Jeep Strokers

finally went to the dyno . it was all good and ready to rock . but then came murphy and is %^$#@^ laws ...
took the jeep to a mustang dyno yesterday, and for some reason the rev limiter decided to kick in at about 4300 rpm on every pass.
there is NO lean spots in the afr no surges, the engine is working great just the rev limiter kicks in early
i did manage to make one pass to 4500rpm but thats it..
i think the FIC is messing with the ecu , did someone else add that problem before ??
here is the my dyno pulls..
264 whp at 4500 and still climbing
44 kg_m at 4000
PICS...



also wondering what could be the final output on this engine if its pulls to 5200rpm like it should ???

just a very wild guess, if your torque goes in an equal bow past the peak it would give around maybe

40kg at 5000rpm is about 285hp

37kg at 5200rpm is about 275hp

SkauneJohan wrote:just a very wild guess, if your torque goes in an equal bow past the peak it would give around maybe

40kg at 5000rpm is about 285hp

37kg at 5200rpm is about 275hp

i can live with that 285 RWHP
just need to fix this damn rev limiter problem

gotta love all the modern electronics and computers NOT

atias wrote:i think the FIC is messing with the ecu

I think you're right.
Anyway, your weather corrected numbers were 259.5hp @ 4600rpm & 308.1lbft @ 4000rpm. I reckon the real peak would have been ~270hp which is excellent.

Cheromaniac wrote:

atias wrote:i think the FIC is messing with the ecu

I think you're right.
Anyway, your weather corrected numbers were 259.5hp @ 4600rpm & 308.1lbft @ 4000rpm. I reckon the real peak would have been ~270hp which is excellent.

thanks . not too bad from a 5 years old daily driver,with your original recipe motor with the cranecam still kicking and a supercharger on top.

gonna try to bypass the msd 6A tomorrow and see if the rev limiter(misfire) still continues.
this is the same rev misfire that you can hear in this video-
http://www.youtube.com/watch?v=HbbNMhrU2X8
the only problem is that it making it at 4300-4500 rpms checked at the rpm gauge + laptop(fic) + dyno computer, all show the same.

SkauneJohan wrote:gotta love all the modern electronics and computers NOT

needs to try the technical tap on the modern electronics also

Make sure you calibrated the FIC to the engine RPM.

Do you have an FIC log from the dyno run?

SilverXJ wrote:Make sure you calibrated the FIC to the engine RPM.

i calibrated the fic using the DRB tool to match the rpms spot on.

SilverXJ wrote:Do you have an FIC log from the dyno run?

yes sir i do.

atias wrote:thanks . not too bad from a 5 years old daily driver,with your original recipe motor with the cranecam still kicking and a supercharger on top.

Yeah, my original build motor with the Crane 753905 cam probably would have put down around 210rwhp/265rwtq in N/A form. How much boost is your supercharger making and do you have an intercooler?

i got 8-9 psi at 5000-5200 rpm, now i'm only seeing 6 at 4300-4500, give or take half a psi.
it have water to air intercooler with a water tank for ice in the back and a heat exchanger up front of the radiator.
water meth injection,split headers with two exhaust systems,43lbs injectors,massively ported 7120 head, Crane 753905 with the 99833 crane valve springs installed at 1.700 height,
aem fic 6, msd 6a ignition, 12 cw crank , 707 connecting rods, sealed power hyperSomething pistons,62mm throttle body,ngk bkr6e sparkplugs,and a very old ALBREX centrifugal supercharger, and probably forgot a few things.

this video is from last year. changed a few things from back then.

Your engine sounds wicked.
The boost numbers seem about right given that with a centrifugal supercharger, boost rises in proportion to the square of the rpm. If your engine was revving to its full potential at 5200rpm, you'd probably be not far short of 300rwhp.

thanks dino .
and the funny thing is that next in line after me on the dyno some guy brought a wrangler jk with a 6.1 hemi conversion and he only got 250 RWHP with is 6000+++ RPMS .

oops, I totally missed out that you have a centrifugal compressor

very cool!

42kg at 5200rpm is equal to 312hp

40kg at 5200rpm is equal to 297hp

so I agree with Dino that around 300hp seems right

Am I missing something here??? The torque and horsepower curve always intersect at 5250rpms!!! According to your graph, they intersect at ~4400rpms. I am suspicious of the indicated engine speed on the graph. It looks like it pulled to more than 5250rpms.