Jeep Strokers

Posted: **May 14th, 2020, 11:39 pm**

Hi guys,

I bought a 4.6 stroker from Chad Golen for my 95er YJ, installed 24lb injectors and 62mm TB he recommends together wih a pace setter header with 2.5 exhaust on the other end. Installed DUI kit for 50 kV ignition together with RC9CY4 spark plugs opened to 0.055. Put a wideband O2 on the header end. Running 4.1 axles with 33" BFG. Gas is at 98 octane here. Chad told me stock PCM and intake is fine for this setup.

I wonder what is proper AFR to gain maximum power? When in WOT my AFR goes down from 12.5 @ 3000 rpm down to 10.8 @ 4500 rpm - seems to be way to rich. The dyno chart Chad gave me shows 13.4 AFR @ 5000 rpm where the engine delivers max. power of 270 HP.

I newer had a Jeep stroker before so I wonder what might be a proper AFR range here: should I try to tune for AFR 13 with my APEXI? Do I have to tune the ignition too?

Any helpful suggestion is welcome.

br Frank

Posted: **May 15th, 2020, 2:22 am**

You mentioned 98 octane fuel so I guess that's RON, equivalent to 93 US.
The ideal AFR for maximum power on a N/A engine at WOT is 12.5-13.0:1, so adjust your fuel curve accordingly. As for ignition timing advance, you can adjust that too if the APEXI allows it. For maximum power, advance until you hear a light ping and then back off a couple of degrees.

Posted: **May 15th, 2020, 3:17 am**

Thanks for fast reply - 12.5 to 13 was the range I had expected for a naturally aspirated engine. And yes, you're right: 98 in Germany is same as 93 in US. Because the engine has a high compression I think it is a good idea to go with it.

Unfortunately I cannot tune the ignition by APEXI, but I've red about guys who modified the CPS. Any idea or experience about the range of advancing it, so I can calculate the width of the holes for moving/adjusting the sensor?

Posted: **May 15th, 2020, 6:38 am**

There are several ways to move the CS towards the passenger side. Slotting, adding an additional plate and moving the sensor itself on the plate or even a combination.

IIRC 3/8-7/16`s works out to be ~ 4 degrees.

Posted: **May 19th, 2020, 5:01 am**

Yesterday I did a test run on the highway and managed to log the AFR and rpm together with some other data. Looks like the PCM dramatically raises fuel injection time from 4000 rpm on (my current fuel consumption in the table is calculated from injection time). Also AFR is to rich. It does not rev past 4500 rpm and even this 4500 rpm does sound like ignition timing, plugs ??? preventing the motor from reving up towards 5000 rpm. Any hints and/or suggestions?

Code: Select all

TIMESTAMP              RPM  SPEED(km/h)  m/h AFR2  LAMBDA2   Curr. FC(l/100km  Curr.mpg 
2020-05-17_22:09:07.40 3600          135  84 13,33      0,91            12,8     18,4
2020-05-17_22:09:07.60 3600          135  84  13,4      0,91            12,8     18,4
2020-05-17_22:09:07.80 3600          135  84 13,58      0,92            12,8     18,4
2020-05-17_22:09:08.00 3600          135  84 13,39      0,91            12,8     18,4
2020-05-17_22:09:08.20 3600          136  84 13,28       0,9            12,8     18,4
2020-05-17_22:09:08.40 3700          135  84 15,46      1,05            12,8     18,4
2020-05-17_22:09:08.60 3700          135  84 15,51      1,06            12,8     18,4
2020-05-17_22:09:08.80 3700          135  84 14,96      1,02            12,8     18,4
2020-05-17_22:09:09.00 3700          135  84 14,21      0,97            12,8     18,4
2020-05-17_22:09:09.20 3700          135  84 13,78      0,94            12,8     18,4
2020-05-17_22:09:09.40 3700          136  84 14,06      0,96            27,5      8,5
2020-05-17_22:09:09.60 3700          136  84 14,12      0,96            27,5      8,5
2020-05-17_22:09:09.80 3700          136  84 14,01      0,95            27,5      8,5
2020-05-17_22:09:10.00 3700          136  84 13,93      0,95            27,5      8,5
2020-05-17_22:09:10.20 3700          136  84 13,86      0,94            27,5      8,5
2020-05-17_22:09:10.40 3700          135  84 13,66      0,93            27,5      8,5
2020-05-17_22:09:10.60 3700          135  84 13,84      0,94            27,5      8,5
2020-05-17_22:09:10.80 3700          135  84 13,66      0,93            27,5      8,5
2020-05-17_22:09:11.00 3700          135  84 13,81      0,94            27,5      8,5
2020-05-17_22:09:11.20 3700          135  84 13,67      0,93            27,5      8,5
2020-05-17_22:09:11.40 3700          135  84 13,79      0,94              24      9,8
2020-05-17_22:09:11.60 3700          135  84 13,84      0,94              24      9,8
2020-05-17_22:09:11.80 3700          135  84 13,73      0,93              24      9,8
2020-05-17_22:09:12.00 3700          135  84 13,81      0,94              24      9,8
2020-05-17_22:09:12.20 3700          135  84 13,88      0,94              24      9,8
2020-05-17_22:09:12.40 3600          135  84 13,68      0,93              24      9,8
2020-05-17_22:09:12.60 3600          135  84 13,87      0,94              24      9,8
2020-05-17_22:09:12.80 3600          135  84 13,66      0,93              24      9,8
2020-05-17_22:09:13.00 3600          136  84 13,61      0,93              24      9,8
2020-05-17_22:09:13.20 3600          136  84 13,74      0,93              24      9,8
2020-05-17_22:09:13.40 3700          136  84 13,89      0,94            24,7      9,5
2020-05-17_22:09:13.60 3700          136  84 13,72      0,93            24,7      9,5
2020-05-17_22:09:13.80 3700          135  84 13,71      0,93            24,7      9,5
2020-05-17_22:09:14.00 3700          135  84 13,98      0,95            24,7      9,5
2020-05-17_22:09:14.20 3700          135  84 13,81      0,94            24,7      9,5
2020-05-17_22:09:14.40 3700          135  84 13,72      0,93            24,7      9,5
2020-05-17_22:09:14.60 3700          135  84 13,71      0,93            24,7      9,5
2020-05-17_22:09:14.80 3700          136  84 13,76      0,94            24,7      9,5
2020-05-17_22:09:15.00 3700          136  84 13,91      0,95            24,7      9,5
2020-05-17_22:09:15.20 3700          136  84 13,62      0,93            24,7      9,5
2020-05-17_22:09:15.40 3700          135  84 13,81      0,94            24,4      9,6
2020-05-17_22:09:15.60 3700          135  84  13,8      0,94            24,4      9,6
2020-05-17_22:09:15.80 3700          135  84 13,88      0,94            24,4      9,6
2020-05-17_22:09:16.00 3700          135  84 13,82      0,94            24,4      9,6
2020-05-17_22:09:16.20 3700          136  84 13,58      0,92            24,4      9,6
2020-05-17_22:09:16.40 3700          137  85 13,74      0,93            24,4      9,6
2020-05-17_22:09:16.60 3700          136  84 13,78      0,94            24,4      9,6
2020-05-17_22:09:16.80 3700          136  84 13,76      0,94            24,4      9,6
2020-05-17_22:09:17.00 3700          136  84 13,67      0,93            24,4      9,6
2020-05-17_22:09:17.20 3700          136  84 13,86      0,94            24,4      9,6
2020-05-17_22:09:17.40 3700          136  84  13,8      0,94            24,4      9,6
2020-05-17_22:09:17.60 3700          137  85 13,84      0,94            24,4      9,6
2020-05-17_22:09:17.80 3700          137  85 13,76      0,94            24,4      9,6
2020-05-17_22:09:18.00 3700          136  84 13,81      0,94            24,4      9,6
2020-05-17_22:09:18.20 3700          136  84 13,75      0,94            24,4      9,6
2020-05-17_22:09:18.40 3700          136  84 13,48      0,92            24,4      9,6
2020-05-17_22:09:18.60 3700          136  84 14,89      1,01            24,4      9,6
2020-05-17_22:09:18.80 3700          136  84 13,26       0,9            24,4      9,6
2020-05-17_22:09:19.00 3700          137  85 13,17       0,9            24,4      9,6
2020-05-17_22:09:19.20 3700          137  85 13,22       0,9            24,4      9,6
2020-05-17_22:09:19.40 3800          138  86  13,3       0,9            24,7      9,5
2020-05-17_22:09:19.60 3800          139  86 13,75      0,94            24,7      9,5
2020-05-17_22:09:20.00 3800          139  86  12,6      0,86            24,7      9,5
2020-05-17_22:09:20.20 3800          140  87 12,36      0,84            24,7      9,5
2020-05-17_22:09:20.40 3800          140  87 12,35      0,84            24,7      9,5
2020-05-17_22:09:20.60 3800          141  88 12,18      0,83            24,7      9,5
2020-05-17_22:09:20.80 3800          142  88 12,16      0,83            24,7      9,5
2020-05-17_22:09:21.00 3800          142  88 12,06      0,82            24,7      9,5
2020-05-17_22:09:21.20 3800          142  88 12,04      0,82            24,7      9,5
2020-05-17_22:09:21.40 3800          143  89 11,93      0,81            24,7      9,5
2020-05-17_22:09:21.60 3800          144  89 11,95      0,81            36,9      6,4
2020-05-17_22:09:21.80 3800          144  89 12,06      0,82            36,9      6,4
2020-05-17_22:09:22.00 3800          145  90  11,9      0,81            36,9      6,4
2020-05-17_22:09:22.20 3800          145  90 11,95      0,81            36,9      6,4
2020-05-17_22:09:22.40 3800          147  91 11,92      0,81            36,9      6,4
2020-05-17_22:09:22.60 4000          147  91 11,93      0,81            36,9      6,4
2020-05-17_22:09:22.80 4000          147  91 11,95      0,81            36,9      6,4
2020-05-17_22:09:23.00 4000          148  92 11,89      0,81            36,9      6,4
2020-05-17_22:09:23.20 4000          149  93 11,77       0,8            36,9      6,4
2020-05-17_22:09:23.40 4000          149  93 11,86      0,81            36,9      6,4
2020-05-17_22:09:23.60 4000          150  93 11,87      0,81            43,6      5,4
2020-05-17_22:09:23.80 4000          150  93 11,88      0,81            43,6      5,4
2020-05-17_22:09:24.00 4000          150  93 11,94      0,81            43,6      5,4
2020-05-17_22:09:24.20 4000          151  94 11,85      0,81            43,6      5,4
2020-05-17_22:09:24.40 4000          152  94 11,96      0,81            43,6      5,4
2020-05-17_22:09:24.60 4000          152  94 11,88      0,81            43,6      5,4
2020-05-17_22:09:24.80 4000          153  95 11,92      0,81            43,6      5,4
2020-05-17_22:09:25.00 4000          154  96 11,99      0,82            43,6      5,4
2020-05-17_22:09:25.20 4000          154  96 11,84      0,81            43,6      5,4
2020-05-17_22:09:25.40 4000          155  96 11,86      0,81            43,6      5,4
2020-05-17_22:09:25.60 4300          155  96 11,84      0,81            44,4      5,3
2020-05-17_22:09:25.80 4300          155  96 11,98      0,81            44,4      5,3
2020-05-17_22:09:26.00 4300          156  97 11,99      0,82            44,4      5,3
2020-05-17_22:09:26.20 4300          156  97 11,91      0,81            44,4      5,3
2020-05-17_22:09:26.40 4300          157  97 11,94      0,81            44,4      5,3
2020-05-17_22:09:26.60 4200          158  98 11,91      0,81            44,4      5,3
2020-05-17_22:09:26.80 4200          158  98    12      0,82            44,4      5,3
2020-05-17_22:09:27.00 4200          158  98 11,94      0,81            44,4      5,3
2020-05-17_22:09:27.20 4200          159  99    12      0,82            44,4      5,3
2020-05-17_22:09:27.40 4200          158  98 11,91      0,81            44,4      5,3
2020-05-17_22:09:27.60 4400          159  99 11,98      0,81            44,5      5,3
2020-05-17_22:09:27.80 4400          159  99 11,91      0,81            44,5      5,3
2020-05-17_22:09:28.00 4400          160  99 11,94      0,81            44,5      5,3
2020-05-17_22:09:28.20 4400          160  99 12,02      0,82            44,5      5,3
2020-05-17_22:09:28.40 4400          161 100 11,72       0,8            44,5      5,3
2020-05-17_22:09:28.60 4300          161 100 11,87      0,81            44,5      5,3
2020-05-17_22:09:28.80 4300          162 101  11,9      0,81            44,5      5,3
2020-05-17_22:09:29.00 4300          162 101 11,85      0,81            44,5      5,3
2020-05-17_22:09:29.20 4300          162 101 11,97      0,81            44,5      5,3
2020-05-17_22:09:29.40 4300          162 101  11,9      0,81            44,5      5,3
2020-05-17_22:09:29.60 4400          162 101 11,93      0,81            44,3      5,3
2020-05-17_22:09:29.80 4400          162 101  11,8       0,8            44,3      5,3
2020-05-17_22:09:30.00 4400          163 101 11,87      0,81            44,3      5,3
2020-05-17_22:09:30.20 4400          163 101 11,82       0,8            44,3      5,3
2020-05-17_22:09:30.40 4400          163 101 11,82       0,8            44,3      5,3
2020-05-17_22:09:30.60 4400          163 101 11,77       0,8            44,3      5,3
2020-05-17_22:09:30.80 4400          164 102 11,72       0,8            44,3      5,3
2020-05-17_22:09:31.00 4400          163 101  11,8       0,8            44,3      5,3
2020-05-17_22:09:31.20 4400          164 102  11,9      0,81            44,3      5,3
2020-05-17_22:09:31.40 4400          164 102  11,8       0,8            44,3      5,3
2020-05-17_22:09:31.60 4400          163 101 11,73       0,8            44,1      5,3
2020-05-17_22:09:31.80 4400          163 101 11,81       0,8            44,1      5,3
2020-05-17_22:09:32.00 4400          164 102 11,75       0,8            44,1      5,3
2020-05-17_22:09:32.20 4400          164 102 11,74       0,8            44,1      5,3
2020-05-17_22:09:32.40 4400          165 102 11,75       0,8            44,1      5,3
2020-05-17_22:09:32.60 4500          165 102 11,73       0,8            44,1      5,3
2020-05-17_22:09:32.80 4500          165 102  11,8       0,8            44,1      5,3
2020-05-17_22:09:33.00 4500          165 102 11,76       0,8            44,1      5,3

Posted: **May 19th, 2020, 6:13 am**

I recently got a hpt tuners and I noticed on my 97 wrangler it does in fact increase the injector timing significantly including the power enrichment at the higher wot rpm range. The timing also backs off at those rpm levels. What exact injectors do you have?

Posted: **May 19th, 2020, 9:11 am**

I installed 4 hole injectors (BOSCH 0280155931, 24 lb) that came with the Golen 4.6 stroker kit. fuel pressure is 38 psi @ WOT. TB is 62 mm.

Posted: **May 19th, 2020, 4:25 pm**

0-280-155-931
28.55 pounds
300 cc
215.8 grams
43.5 psi
3 bar
Those are 28.5 pound injectors at 43.5 psi. Haven't built my stroker yet but all the info ive accrued for my build is 24# @43.5psi injector are the biggest I need naturally asperated.

Posted: **May 19th, 2020, 4:30 pm**

Don't forget the ECM goes back into open loop at ~72-75% throttle. There is where the sudden fuel dump is happening.

You should also be able to see the fuel trim delays at lower RPM before enrichment starts.

I run Accel 24`s at 42 psi with the trim delay set to 0 and the trim itself pulled back.

Posted: **May 19th, 2020, 4:39 pm**

Using the calculator you are at 26.6 pounds at 38 psi im at 25.5 psi at 49 psi.

Posted: **May 19th, 2020, 5:24 pm**

FrankKoba wrote: ↑May 19th, 2020, 5:01 am Yesterday I did a test run on the highway and managed to log the AFR and rpm together with some other data. Looks like the PCM dramatically raises fuel injection time from 4000 rpm on (my current fuel consumption in the table is calculated from injection time). Also AFR is to rich. It does not rev past 4500 rpm and even this 4500 rpm does sound like ignition timing, plugs ??? preventing the motor from reving up towards 5000 rpm. Any hints and/or suggestions?

Code: Select all

TIMESTAMP              RPM  SPEED(km/h)  m/h AFR2  LAMBDA2   Curr. FC(l/100km  Curr.mpg 
2020-05-17_22:09:07.40 3600          135  84 13,33      0,91            12,8     18,4
2020-05-17_22:09:07.60 3600          135  84  13,4      0,91            12,8     18,4
2020-05-17_22:09:07.80 3600          135  84 13,58      0,92            12,8     18,4
2020-05-17_22:09:08.00 3600          135  84 13,39      0,91            12,8     18,4
2020-05-17_22:09:08.20 3600          136  84 13,28       0,9            12,8     18,4
2020-05-17_22:09:08.40 3700          135  84 15,46      1,05            12,8     18,4
2020-05-17_22:09:08.60 3700          135  84 15,51      1,06            12,8     18,4
2020-05-17_22:09:08.80 3700          135  84 14,96      1,02            12,8     18,4
2020-05-17_22:09:09.00 3700          135  84 14,21      0,97            12,8     18,4
2020-05-17_22:09:09.20 3700          135  84 13,78      0,94            12,8     18,4
2020-05-17_22:09:09.40 3700          136  84 14,06      0,96            27,5      8,5
2020-05-17_22:09:09.60 3700          136  84 14,12      0,96            27,5      8,5
2020-05-17_22:09:09.80 3700          136  84 14,01      0,95            27,5      8,5
2020-05-17_22:09:10.00 3700          136  84 13,93      0,95            27,5      8,5
2020-05-17_22:09:10.20 3700          136  84 13,86      0,94            27,5      8,5
2020-05-17_22:09:10.40 3700          135  84 13,66      0,93            27,5      8,5
2020-05-17_22:09:10.60 3700          135  84 13,84      0,94            27,5      8,5
2020-05-17_22:09:10.80 3700          135  84 13,66      0,93            27,5      8,5
2020-05-17_22:09:11.00 3700          135  84 13,81      0,94            27,5      8,5
2020-05-17_22:09:11.20 3700          135  84 13,67      0,93            27,5      8,5
2020-05-17_22:09:11.40 3700          135  84 13,79      0,94              24      9,8
2020-05-17_22:09:11.60 3700          135  84 13,84      0,94              24      9,8
2020-05-17_22:09:11.80 3700          135  84 13,73      0,93              24      9,8
2020-05-17_22:09:12.00 3700          135  84 13,81      0,94              24      9,8
2020-05-17_22:09:12.20 3700          135  84 13,88      0,94              24      9,8
2020-05-17_22:09:12.40 3600          135  84 13,68      0,93              24      9,8
2020-05-17_22:09:12.60 3600          135  84 13,87      0,94              24      9,8
2020-05-17_22:09:12.80 3600          135  84 13,66      0,93              24      9,8
2020-05-17_22:09:13.00 3600          136  84 13,61      0,93              24      9,8
2020-05-17_22:09:13.20 3600          136  84 13,74      0,93              24      9,8
2020-05-17_22:09:13.40 3700          136  84 13,89      0,94            24,7      9,5
2020-05-17_22:09:13.60 3700          136  84 13,72      0,93            24,7      9,5
2020-05-17_22:09:13.80 3700          135  84 13,71      0,93            24,7      9,5
2020-05-17_22:09:14.00 3700          135  84 13,98      0,95            24,7      9,5
2020-05-17_22:09:14.20 3700          135  84 13,81      0,94            24,7      9,5
2020-05-17_22:09:14.40 3700          135  84 13,72      0,93            24,7      9,5
2020-05-17_22:09:14.60 3700          135  84 13,71      0,93            24,7      9,5
2020-05-17_22:09:14.80 3700          136  84 13,76      0,94            24,7      9,5
2020-05-17_22:09:15.00 3700          136  84 13,91      0,95            24,7      9,5
2020-05-17_22:09:15.20 3700          136  84 13,62      0,93            24,7      9,5
2020-05-17_22:09:15.40 3700          135  84 13,81      0,94            24,4      9,6
2020-05-17_22:09:15.60 3700          135  84  13,8      0,94            24,4      9,6
2020-05-17_22:09:15.80 3700          135  84 13,88      0,94            24,4      9,6
2020-05-17_22:09:16.00 3700          135  84 13,82      0,94            24,4      9,6
2020-05-17_22:09:16.20 3700          136  84 13,58      0,92            24,4      9,6
2020-05-17_22:09:16.40 3700          137  85 13,74      0,93            24,4      9,6
2020-05-17_22:09:16.60 3700          136  84 13,78      0,94            24,4      9,6
2020-05-17_22:09:16.80 3700          136  84 13,76      0,94            24,4      9,6
2020-05-17_22:09:17.00 3700          136  84 13,67      0,93            24,4      9,6
2020-05-17_22:09:17.20 3700          136  84 13,86      0,94            24,4      9,6
2020-05-17_22:09:17.40 3700          136  84  13,8      0,94            24,4      9,6
2020-05-17_22:09:17.60 3700          137  85 13,84      0,94            24,4      9,6
2020-05-17_22:09:17.80 3700          137  85 13,76      0,94            24,4      9,6
2020-05-17_22:09:18.00 3700          136  84 13,81      0,94            24,4      9,6
2020-05-17_22:09:18.20 3700          136  84 13,75      0,94            24,4      9,6
2020-05-17_22:09:18.40 3700          136  84 13,48      0,92            24,4      9,6
2020-05-17_22:09:18.60 3700          136  84 14,89      1,01            24,4      9,6
2020-05-17_22:09:18.80 3700          136  84 13,26       0,9            24,4      9,6
2020-05-17_22:09:19.00 3700          137  85 13,17       0,9            24,4      9,6
2020-05-17_22:09:19.20 3700          137  85 13,22       0,9            24,4      9,6
2020-05-17_22:09:19.40 3800          138  86  13,3       0,9            24,7      9,5
2020-05-17_22:09:19.60 3800          139  86 13,75      0,94            24,7      9,5
2020-05-17_22:09:20.00 3800          139  86  12,6      0,86            24,7      9,5
2020-05-17_22:09:20.20 3800          140  87 12,36      0,84            24,7      9,5
2020-05-17_22:09:20.40 3800          140  87 12,35      0,84            24,7      9,5
2020-05-17_22:09:20.60 3800          141  88 12,18      0,83            24,7      9,5
2020-05-17_22:09:20.80 3800          142  88 12,16      0,83            24,7      9,5
2020-05-17_22:09:21.00 3800          142  88 12,06      0,82            24,7      9,5
2020-05-17_22:09:21.20 3800          142  88 12,04      0,82            24,7      9,5
2020-05-17_22:09:21.40 3800          143  89 11,93      0,81            24,7      9,5
2020-05-17_22:09:21.60 3800          144  89 11,95      0,81            36,9      6,4
2020-05-17_22:09:21.80 3800          144  89 12,06      0,82            36,9      6,4
2020-05-17_22:09:22.00 3800          145  90  11,9      0,81            36,9      6,4
2020-05-17_22:09:22.20 3800          145  90 11,95      0,81            36,9      6,4
2020-05-17_22:09:22.40 3800          147  91 11,92      0,81            36,9      6,4
2020-05-17_22:09:22.60 4000          147  91 11,93      0,81            36,9      6,4
2020-05-17_22:09:22.80 4000          147  91 11,95      0,81            36,9      6,4
2020-05-17_22:09:23.00 4000          148  92 11,89      0,81            36,9      6,4
2020-05-17_22:09:23.20 4000          149  93 11,77       0,8            36,9      6,4
2020-05-17_22:09:23.40 4000          149  93 11,86      0,81            36,9      6,4
2020-05-17_22:09:23.60 4000          150  93 11,87      0,81            43,6      5,4
2020-05-17_22:09:23.80 4000          150  93 11,88      0,81            43,6      5,4
2020-05-17_22:09:24.00 4000          150  93 11,94      0,81            43,6      5,4
2020-05-17_22:09:24.20 4000          151  94 11,85      0,81            43,6      5,4
2020-05-17_22:09:24.40 4000          152  94 11,96      0,81            43,6      5,4
2020-05-17_22:09:24.60 4000          152  94 11,88      0,81            43,6      5,4
2020-05-17_22:09:24.80 4000          153  95 11,92      0,81            43,6      5,4
2020-05-17_22:09:25.00 4000          154  96 11,99      0,82            43,6      5,4
2020-05-17_22:09:25.20 4000          154  96 11,84      0,81            43,6      5,4
2020-05-17_22:09:25.40 4000          155  96 11,86      0,81            43,6      5,4
2020-05-17_22:09:25.60 4300          155  96 11,84      0,81            44,4      5,3
2020-05-17_22:09:25.80 4300          155  96 11,98      0,81            44,4      5,3
2020-05-17_22:09:26.00 4300          156  97 11,99      0,82            44,4      5,3
2020-05-17_22:09:26.20 4300          156  97 11,91      0,81            44,4      5,3
2020-05-17_22:09:26.40 4300          157  97 11,94      0,81            44,4      5,3
2020-05-17_22:09:26.60 4200          158  98 11,91      0,81            44,4      5,3
2020-05-17_22:09:26.80 4200          158  98    12      0,82            44,4      5,3
2020-05-17_22:09:27.00 4200          158  98 11,94      0,81            44,4      5,3
2020-05-17_22:09:27.20 4200          159  99    12      0,82            44,4      5,3
2020-05-17_22:09:27.40 4200          158  98 11,91      0,81            44,4      5,3
2020-05-17_22:09:27.60 4400          159  99 11,98      0,81            44,5      5,3
2020-05-17_22:09:27.80 4400          159  99 11,91      0,81            44,5      5,3
2020-05-17_22:09:28.00 4400          160  99 11,94      0,81            44,5      5,3
2020-05-17_22:09:28.20 4400          160  99 12,02      0,82            44,5      5,3
2020-05-17_22:09:28.40 4400          161 100 11,72       0,8            44,5      5,3
2020-05-17_22:09:28.60 4300          161 100 11,87      0,81            44,5      5,3
2020-05-17_22:09:28.80 4300          162 101  11,9      0,81            44,5      5,3
2020-05-17_22:09:29.00 4300          162 101 11,85      0,81            44,5      5,3
2020-05-17_22:09:29.20 4300          162 101 11,97      0,81            44,5      5,3
2020-05-17_22:09:29.40 4300          162 101  11,9      0,81            44,5      5,3
2020-05-17_22:09:29.60 4400          162 101 11,93      0,81            44,3      5,3
2020-05-17_22:09:29.80 4400          162 101  11,8       0,8            44,3      5,3
2020-05-17_22:09:30.00 4400          163 101 11,87      0,81            44,3      5,3
2020-05-17_22:09:30.20 4400          163 101 11,82       0,8            44,3      5,3
2020-05-17_22:09:30.40 4400          163 101 11,82       0,8            44,3      5,3
2020-05-17_22:09:30.60 4400          163 101 11,77       0,8            44,3      5,3
2020-05-17_22:09:30.80 4400          164 102 11,72       0,8            44,3      5,3
2020-05-17_22:09:31.00 4400          163 101  11,8       0,8            44,3      5,3
2020-05-17_22:09:31.20 4400          164 102  11,9      0,81            44,3      5,3
2020-05-17_22:09:31.40 4400          164 102  11,8       0,8            44,3      5,3
2020-05-17_22:09:31.60 4400          163 101 11,73       0,8            44,1      5,3
2020-05-17_22:09:31.80 4400          163 101 11,81       0,8            44,1      5,3
2020-05-17_22:09:32.00 4400          164 102 11,75       0,8            44,1      5,3
2020-05-17_22:09:32.20 4400          164 102 11,74       0,8            44,1      5,3
2020-05-17_22:09:32.40 4400          165 102 11,75       0,8            44,1      5,3
2020-05-17_22:09:32.60 4500          165 102 11,73       0,8            44,1      5,3
2020-05-17_22:09:32.80 4500          165 102  11,8       0,8            44,1      5,3
2020-05-17_22:09:33.00 4500          165 102 11,76       0,8            44,1      5,3

Its too rich imo at anything below 12:1 for naturally asperated. 12.5: would be ideal. do you have a way of taking some fuel out above 3800? have you done the cps mod to advance the base timing? Im thinking those injectors are a bit too big.

Posted: **May 20th, 2020, 11:54 am**

The Golen engine kit stated 24 lb for the injectors, but from the BOSCH spec sheet I think you are right and I would assume 26.6 lb is way to much for this engine and the 62mm TB. I wonder why Chad Golen recommends such big injectors for his stroker. My PCM is ODB1 so the only chance I have is manipulating the MAP signal using my APEXI - I will give it another try tomorrow and report the outcome.

Btw: any recommendation where to start for cps advancing?

Posted: **May 21st, 2020, 10:21 am**

Did Chad sell those injectors to you? The specs ive found says they are not 24# injectors for sure. Imo id swap them out or throw a turbo on it as rich as it is lol. If he sold them to you let him know how rich it is maybe he give you another set. As far as cps mod do a search on this forum it will come up.Btw id close the spark plug gaps and run about .035 gap could be why it wont pull past 4500. Too much gap and the spark wont jump the gap under high load. experienced that in my drag race days. lean it out and it should pull to 5000. leaner is meaner.

Posted: **May 21st, 2020, 3:09 pm**

Yes, Chad put these injectors togeter with the 62 mm TB in the engine box.

I followed your recommendation and gapped the RC9YC4 from 0.055 (as recommended by the D.U.I. documentation) to about 0.04 and managed the fuel trim to go much leaner using the APEXI SAFC2. Here are the results:

Code: Select all

    RPM       SPEED      AFR2      LAMBDA2     TEMP.     CUR.FC.  
   4300        160       13,29      0,90       21,1       39,1    
   4300        161       13,39      0,91       21,1       39,1    
   4300        160       13,47      0,92       21,1       39,1    
   4300        161       13,41      0,91       21,1       39,1    
   4300        161       13,35      0,91       21,1       39,1    
   4400        161       13,34      0,91       21,1        39     
   4400        161       13,3       0,90       21,1        39     
   4400        162       13,29      0,90       21,1        39     
   4400        162       13,42      0,91       21,1        39     
   4400        161       13,33      0,91       21,1        39     
   4400        162       13,41      0,91       21,1        39     
   4400        162       13,33      0,91       21,1        39     
   4400        162       13,34      0,91       21,1        39     
   4400        162       13,29      0,90       21,1        39     
   4400        162       13,33      0,91       21,1        39     
   4400        162       13,29      0,90       21,1       38,7    
   4400        163       13,36      0,91       21,1       38,7    
   4400        163       13,29      0,90       21,1       38,7    
   4400        163       13,26      0,90       21,1       38,7    
   4400        163       13,29      0,90       21,1       38,7    
   4400        163       13,3       0,90       21,1       38,7    
   4400        163       13,31      0,91       21,1       38,7    
   4400        164       13,34      0,91       21,1       38,7    
   4400        163       13,36      0,91       21,1       38,7    
   4400        164       13,3       0,90       21,1       38,7    
   4400        164       13,27      0,90       21,1       38,9    
   4400        164       13,28      0,90       21,1       38,9    
   4400        164       13,31      0,91       21,1       38,9    
   4400        165       13,34      0,91       21,1       38,9    
   4400        165       13,26      0,90       21,1       38,9    
   4400        165       13,23      0,90       21,1       38,9    
   4400        165       13,28      0,90       21,1       38,9    
   4400        165       13,22      0,90       21,1       38,9    
   4400        165       13,2       0,90       21,1       38,9    
   4400        165       13,14      0,89       21,1       38,9    
   4500        165       13,24      0,90       21,1       38,8    
   4500        165       13,27      0,90       21,1       38,8    
   4500        165       13,26      0,90       21,1       38,8    
   4500        166       13,24      0,90       21,1       38,8    
   4500        166       13,22      0,90       21,1       38,8    
   4500        166       13,26      0,90       21,1       38,8    
   4500        167       13,29      0,90       21,1       38,8    
   4500        167       13,17      0,90       21,1       38,8    
   4500        166       13,08      0,89       21,1       38,8    
   4500        167       13,25      0,90       21,1       38,8    
   4500        167       13,22      0,90       21,1       38,5    
   4500        167       13,13      0,89       21,1       38,5    
   4500        168       13,24      0,90       21,1       38,5    
   4500        168       13,28      0,90       21,1       38,5    
   4500        168       13,19      0,90       21,1       38,5    
   4600        167       13,25      0,90       21,1       38,5    
   4600        168       13,29      0,90       21,1       38,5    
   4600        167       13,31      0,91       21,1       38,5    
   4600        168       13,34      0,91       21,1       38,5    
   4600        168       13,25      0,90       21,1       38,5    
   4500        168       13,26      0,90       21,1       38,3    
   4500        168       13,36      0,91       21,1       38,3    
   4500        168       13,26      0,90       21,1       38,3    
   4500        168       13,29      0,90       21,1       38,3    
   4500        168       13,37      0,91       21,1       38,3    
   4500        168       13,31      0,91       21,1       38,3    
   4500        168       13,38      0,91       21,1       38,3    
   4500        168       13,29      0,90       21,1       38,3    
   4500        169       13,42      0,91       21,1       38,3    
   4500        169       13,31      0,91       21,1       38,3    
   4500        169       13,23      0,90       21,1        38     
   4500        169       13,38      0,91       21,1        38     
   4500        170       13,24      0,90       21,1        38     
   4500        169       13,37      0,91       21,1        38     
   4500        169       13,27      0,90       21,1        38     
   4600        170       13,36      0,91       21,1        38     
   4600        170       13,39      0,91       21,1        38     
   4600        170       13,42      0,91       21,1        38     
   4600        170       13,36      0,91       21,1        38     
   4600        170       13,29      0,90       21,1        38     
   4500        170       13,38      0,91       21,1       37,7    
   4500        170       13,33      0,91       21,1       37,7    
   4500        171       13,29      0,90       21,1       37,7    
   4500        170       13,37      0,91       21,1       37,7    
   4500        171       13,37      0,91       21,1       37,7    
   4600        171       13,35      0,91       21,1       37,7    
   4600        171       13,34      0,91       21,1       37,7    
   4600        171       13,28      0,90       21,1       37,7    
   4600        171       13,47      0,92       21,1       37,7    
   4600        171       13,41      0,91       21,1       37,7    
   4600        171       13,34      0,91       21,1       37,8    
   4600        172       13,38      0,91       21,1       37,8    
   4600        172       13,39      0,91       21,1       37,8    
   4600        173       13,4       0,91       21,1       37,8    
   4600        173       13,34      0,91       21,1       37,8    
   4800        173       13,38      0,91       21,1       37,8    
   4800        173       13,47      0,92       21,1       37,8    
   4800        173       13,43      0,91       21,1       37,8    
   4800        173       13,29      0,90       21,1       37,8    
   4800        173       13,44      0,91       21,1       37,8    
   4600        174       13,36      0,91       21,1       37,4    
   4600        174       13,39      0,91       21,1       37,4    
   4600        173       13,42      0,91       21,1       37,4    
   4600        174       13,41      0,91       21,1       37,4    
   4600        175       13,39      0,91       21,1       37,4    
   4800        174       13,38      0,91       21,1       37,4    
   4800        175       13,28      0,90       21,1       37,4    
   4800        175       13,41      0,91       21,1       37,4    
   4800        175       13,41      0,91       21,1       37,4    
   4800        175       13,4       0,91       21,1       37,4    
   4800        175       13,39      0,91       21,1        37     
   4800        175       13,35      0,91       21,1        37     
   4800        175       13,38      0,91       21,1        37     
   4800        175       13,44      0,91       21,1        37     
   4800        175       13,42      0,91       21,1        37     
   4800        177       13,43      0,91       20,6        37     
   4800        176       13,45      0,91       20,6        37     
   4800        176       13,44      0,91       20,6        37     
   4800        177       13,34      0,91       20,6        37     
   4800        177       13,35      0,91       20,6        37     
   4800        176       13,47      0,92       20,6       36,5    
   4800        177       13,4       0,91       20,6       36,5    
   4800        178       13,41      0,91       20,6       36,5    
   4800        177       13,43      0,91       20,6       36,5    
   4800        178       13,41      0,91       20,6       36,5    
   4900        178       13,48      0,92       20,6       36,5    
   4900        178       13,33      0,91       20,6       36,5    
   4900        177       13,45      0,91       20,6       36,5    
   4900        178       13,41      0,91       20,6       36,5    
   4900        178       13,35      0,91       20,6       36,5

It is way better performance (test run was on slightly ascending highway) and the feeling at the high rpms was not perfect but much much better. I will narrow the gap a bit more and try again. I will also test NGK ZFR7F-11 which should be as cold as RC9YC4 but has longer elektrodes.

@Tolemar: Thanks a lot for this "enlightenment".

Posted: **May 22nd, 2020, 7:18 am**

Looks a bit lean id add a little back try and get the wot in the 12s especially in the higher rpm range 4000 and up. Yea general consenses on spark is wider gaps is better but in reality it is not. At higher rpm that coil is working harder(less time) to jump a further gap and ive seen my engine start to miss at the higher rpm levels even with a msd an high output coil. I closed the gap and the problem went away.

Jeep Strokers

Best AFR for 4.6 golen engine?

Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?

Re: Best AFR for 4.6 golen engine?