Jeep Strokers

Plechtan wrote:If you get a chance, try running a basic 4.6 with the 99+ intake. Be interesting to see how the numbers compare.

I've done that already and the results are hardly mind-blowing, and not even close to Hesco's super-overinflated dyno numbers. Then again, that's exactly what i expected if you remember what i said in the EAP thread. Here are my "before and after" numbers:

Old Intake: 199.8rwhp @ 4750rpm, 253.7rwtq @ 3500rpm
New intake: 201.7rwhp @ 4700rpm, 258.2rwtq @ 3400rpm, maximum gain 5rwtq at 3400rpm

Same dyno, both weather corrected, no changes except for the intake manifold swap and bumping the MAP voltage up from 5.1 to 5.2v to correct a slightly lean condition caused by the new manifold.
So there you have it: 1.9rwhp, 4.5rwtq, torque curve shifted slightly to the left, and a near-1mpg gain in fuel economy.
I'm still happy because I had realistic expectations from the manifold swap and never believed all the hype.
Here's my dyno sheet with a nice, flat torque curve from 1500-4500rpm:

The reason why I'm going with the Unichip is because it can modify afrs in all rpm and load ranges and modify the timing as well. I like the fact that it has the complete 3 harnesses to interface the obd2 pcm. I can bump redline up(don't wanna see anything over 5500 with this setup), lose the governor(I have a switch already that cut's the speedo input to the pcm--has seen 136 once), and engage the aux fan earlier(I have a switch for that too). Silver has had all these mods reflashed to his now blown pcm by Kolak(maybe the pcm didn't like the mods). I do wish I could program it myself(DYI is the mantra), but I'll have a tuning guru tweak it(a Jeeps gotta be cake compared to a GTR, right?). Road tuning the psc1 was fun(illegal at times) but I couldn't touch the closed loop and I needed an ftc to adjust timing(it retards the timing, but if you retard 355*, you actually advance 5*). I soaked my psc1 months ago and assumed it was dead(had no map output) until I got the good response from split sec last week. So during the time I ordered the Uni, I have found out the psc1 is ok and also that I can keep the pcm in OL constantly(helping Ecomike over on Naxja) and dial in whatever afrs I want across the whole rpm/load range(backburner). I have had this itch with Unichip that I want to scratch--even if it means I blow $800 chasing 20hp. Can't forget about the dyno sheet . . .

The OBD II computers (especially '00+) are much fussier about mods than OBD I so I'd say a chip tune is almost mandatory on '96+ models to optimize the fuel/timing curves. The Unichip is probably one of the best for 4.0L/stroker Jeeps but the Split Second FTC1 is also very good.

http://www.splitsec.com/products/ftc1/ftc1ds.htm

The FTC1 also provides timing control in addition to fuel control. The PSC1 only provides fuel control so its function is similar to that of the Apexi SAFC.

gradon wrote:The reason why I'm going with the Unichip is because it can modify afrs in all rpm and load ranges and modify the timing as well. I like the fact that it has the complete 3 harnesses to interface the obd2 pcm. I can bump redline up(don't wanna see anything over 5500 with this setup), lose the governor(I have a switch already that cut's the speedo input to the pcm--has seen 136 once), and engage the aux fan earlier(I have a switch for that too). Silver has had all these mods reflashed to his now blown pcm by Kolak(maybe the pcm didn't like the mods). I do wish I could program it myself(DYI is the mantra), but I'll have a tuning guru tweak it(a Jeeps gotta be cake compared to a GTR, right?). Road tuning the psc1 was fun(illegal at times) but I couldn't touch the closed loop and I needed an ftc to adjust timing(it retards the timing, but if you retard 355*, you actually advance 5*). I soaked my psc1 months ago and assumed it was dead(had no map output) until I got the good response from split sec last week. So during the time I ordered the Uni, I have found out the psc1 is ok and also that I can keep the pcm in OL constantly(helping Ecomike over on Naxja) and dial in whatever afrs I want across the whole rpm/load range(backburner). I have had this itch with Unichip that I want to scratch--even if it means I blow $800 chasing 20hp. Can't forget about the dyno sheet . . .

Does the Unichip really do all of that? I though it just did fuel and timing like the Splict Second FTC1. I know the FTC1 is a wire in, abd the unichip is a plug in, so is that and the ability to tune yourself the major differences?

gradon wrote: Silver has had all these mods reflashed to his now blown pcm by Kolak(maybe the pcm didn't like the mods).

Nah... it worked fine for quite a while.. only ater the battery was drained and charged several times did the PCM have troubles. I did like all the features the kolak upgrade gave me, as you say, the electric fan comes on earlier, firmer shifts, a/c off in WOT for 10 seconds, higher idle, etc. From what the company told me it seems like they use a hex editor on the PCM as they don't have the original code.

I do wish I could program it myself(DYI is the mantra), but I'll have a tuning guru tweak it(a Jeeps gotta be cake compared to a GTR, right?). Road tuning the psc1 was fun(illegal at times) but I couldn't touch the closed loop and I needed an ftc to adjust timing(it retards the timing, but if you retard 355*, you actually advance 5*).

Thats the one thing I really don't like about the Unichip.. you need someone to tune it for you. I agree with you about road tunning. Always fun doing WOT runs.

I can keep the pcm in OL constantly(helping Ecomike over on Naxja)

Are you talking about un plugging the temp sensors?

$800 chasing 20hp.

$800??

Cheromaniac wrote:The OBD II computers (especially '00+) are much fussier about mods than OBD I so I'd say a chip tune is almost mandatory on '96+ models to optimize the fuel/timing curves.

I wouldn't say OBDII is that fussy. I have done many mods to the 4.0L and strokers and the OBDII never complained.

It is not true that you can't tune the unichip, you can. It just costs $1,000.00 for the programming software, but you can program as many as you want. So get a group of friends togather and have them chip in.

The unit cost me $407 and it costs another $300-400 to get it custom tuned. If I went back with the psc1, I'd put the jet2 chip back in to advance the timing(which made mine ping from 2200-3000,instead of 2500-3000 CL), unplug the cts, which leaves it in OL, and make a complete map across the rpms/loads. No more zeroing fuel trims in CL and no longer would I be stuck with 14.7 at part throttle in the 2K+ range. I would drop the afrs to 13s to get rid of the ping and take advantage of the extra timing. The only drawback is idle, which would have to stay 13.0-13.5 even after warmup and the cel from the now disco'd cts. I'm a bit curious, to say the least.

So it's possible to make my Jeep never see open loop? Is that necessary with an FTC1 or will it only adjust closed loop operation?

PolloLoco wrote:So it's possible to make my Jeep never see open loop? Is that necessary with an FTC1 or will it only adjust closed loop operation?

No, you can keep it in open loop by unpluging the coolant temp sensor, so the computer never thinks that the engine gets up to temp.

RAPTORFAN85 wrote:No, you can keep it in open loop by unpluging the coolant temp sensor, so the computer never thinks that the engine gets up to temp.

Damnit I got open and closed loop confused. I had it right the first time then I edited it.

What I can do is keep it in the mode where it does not give fuel based on its pre-programmed fuel maps, correct?

Correct, in open loop it won't run on the predefined maps in the computer, it will give fuel based on the sensor inputs. (O2, MAP, etc...)

I just looked at the Split Second product brochure and the FTC1 only retards up to 20*. It seems that it's meant for boosted applications where you may need to retard the timing to run less-than-premium fuel.

" Only 20 deg" ? Seems like quite a bit to me

Plechtan wrote:" Only 20 deg" ? Seems like quite a bit to me

My bad, I meant to quote this from an earlier post in this thread:

gradon wrote:I couldn't touch the closed loop and I needed an ftc to adjust timing(it retards the timing, but if you retard 355*, you actually advance 5*).

My point is that the FTC1 cannot be used to advance the timing, not even by retarding an extreme amount. Now I need to find a way to advance the timing. Can I just do that with the timing chain for the camshaft? Mopar cams have no advance.