Ok, so my car went to MTI on Sat to get the stage II heads installed. Previously I had their C1 cam, off road X-pipe, Pully, TPIS Headers, MTI Ram Air and PCM Reporgram. It dyno'd at 385/380. Decent numbers, but to tell you the truth, I was a little disapointed. It did seem faster than the numbers indicated though. Raced a couple cars from a roll that trap 122 and beat them. So I was happy with the performance.
Since my last visit to MTI, I added only the Borla Stinger Exh. When they baselined it again on Monday Am, it made 405/402!!! So I picked up 20 Hp and 22 Tq with just this exh??? I have about 3000 more miles on it now and I am sure that accounts for some of it, but I am still pretty happy. Can't wait for the numbers later in the week with the heads on!!! Hey this would be a great advertisement for Borla!

 

Ok, just got the dyno sheet faxed from MTI: Final numbers with heads 437 RWHP 412 RWTQ!

 

Excellent numbers - hope you get it to the track and get the beast tamed soon :)

Les

 

I would contribute some of the gain to PCM relearn. If you were running the stock exhaust, I would also contribute the free flowing (read: zero restriction) of the Borla's as well. Nice numbers never the less. :cheers: :cool: :cheers:

 

Great numbers!Congratulations.What are the spec on your cam? :cool: :cool: :cheers:

 

Well, I had the PCM reprogramed when I had the cam installed, so I don't think that was a factor. Between the time I left MTI with the cam install and came back for the heads, trhe only diff was the exh...


The cam is the MTI C1 and the specs are as follows:
Dur: 222/222 Lift: 566/566 LSA: 112

 

Just because it was programmed, doesn't mean it had relearned. These PCM's are always adjusting, and I can guarantee you, you picked up some from the relearn. A good example of the relearn, came from John Page at 21st Century Muscle Cars (the new LPE shop in Dallas). They installed a Blackwing on an '02 Z06, did before & after dyno, and gained 6 rwhp. After a weeks worth of driving, they dynoed again, and it gained another 4 rwhp. You have LTFT (long term fuel trim), which can only be relearned from an extended period of driving. They are set from the factory for the stock application, and any modifications will cause them to run incorrectly until they have properly relearned. Sorry to be long winded, but the PCM does have to relearn for maximum gains, and not just for 5 minutes. :cheers:

 

Ok, so are you telling me that I will gain even more HP in the comming weeks? Thanks, I am even happier now! :D


[Modified by MillenniumVette, 9:33 AM 9/12/2002]

 

I knew the Borlas were good for 20 rwhp on a 99 coupe with that stock exhaust system but didn't know you could get comparable improvements with the 02/03 Z06 that already has a less restrictive stock exhaust. Interesting...

But it sounds like you have a higher lift cam which may benefit more from the less restrictive Borlas than a bone stock engine... Does anyone have numbers on the Borlas on a bone stock 02/03 Z06? Do the Cats have to go bye bye with the Borlas? Please excuse the ignorance on this point.

I do agree with the PCM re-learning theory. :cheers:

 

If his PCM was programmed properly then I seriously doubt that his HP gain was caused by a PCM relearn. LTFT values are used as a correction values to fix fuel-metering errors. The PCM reads your various sensors (MAF, MAP, RPM, ECT, etc..) and provides the mixture it thinks is required to get 14.7:1. If the O2 sensors tell the PCM that the mixture is off during closed loop operation then the PCM will then start to compensate with STFT, which eventually becomes LTFT.

If the PCM was properly programmed than the fuel trims should be somewhere near zero, and definitely less than +5% after driving around for 100 miles or so. This should not have a major impact on his WOT power.

The only situation I can picture where a relearn would cause a pretty big power gain would be if the PCM programming was really off and the car was running very lean closed loop and WOT. The relearn would fatten things up and bring it back closer to where it should be. Looking at another possibility, if the PCM programming was causing a very rich situation a relearn would lean out closed loop but it would not help at WOT because the PCM will not lean out WOT and risk detonation or burned cats. The PCM will never lean the WOT Power Enrichment tables. This would leave you with a rich WOT mixture even after the relearn. Again, if the PCM was programmed properly none of this should be an issue. The power difference after a relearn should not be all that much. If it is then your programming is off.

The power difference should be coming from the exhaust change. As far as the BlackWing example goes, something sounds off there. Most stock cars with just a BlackWing eventually end up running with fairly high LTFT values after a relearn. This can cause an overly rich condition at WOT, which usually causes a loss of some power. I am guessing that his 4 HP gain was caused by dynoing the car on a different day with different weather, different correction values, or even different gas.

Every car can be a bit different so YMMV.

 

Also, my point was not that "ALL" the gains were from PCM relearn (see earlier post above). I am saying part of the gains were from PCM, but most were due to the less restrictive properties of the exhaust, essentially with no mufflers.

Dyno again in a few weeks, and see what you're at. :cheers:

 

There is no way that any of us can determine that from our keyboards. This depends entirely on how well the PCM was programmed. For all we know the PCM may now be going overly rich at WOT after it corrects for a lean closed loop condition. This would cause a small loss in WOT power from the rich condition.

The only way to see what is actually happening is to scan the car with an ODBII scan tool after logging about 100 miles, along with checking the WOT ratio with a wideband.

:cheers:

 

Are your cats off?

 

Here are the cam specs from MTI

B1 221 221 .558 .558 114
T1 221 221 .558 .558 112
C1 222 222 .566 .566 112
C2 224 224 .581 .581 112
X1 230 227 .591 .571 112
R1* 232 237 .560 .560 114
S1* 244 244 .612 .612 112


Nice numbers. How is the idle? I have heard they are making 440-450 with the X1. But I haven't heard either the C1 or the X1 at idle. Also, I wonder if they will pass emissions...

 

I believe the answer is there...no. :)

 

Thanks for the specs J-Rod. Would internal engine mod (pistons) be necessary with the X1? Wonder what the idle is like also--hopefully Lumpy :yesnod: :yesnod: :) :cheers:

 

The idle is a bit lumpy, but I love it. Has never stalled even once. Runs pretty much like a stocker, except with a lot more HP!

 

good job dale-

i wonder what mine is doing now since its been a couple months :eek:

hopefully i should be over the 400 mark since ive got a little more aggressive (C2) cam.

even though youll beat me, i still wanna get a run in ! !

 

Thanks Kevin! I will be at Fudds tomorrow night if the weather is good. I read that a bunch of the guys were out last tuesday as well for some runs, so maybe we could do something tonight..... I put a post up on Viv's board to see if anyone was interested in some runs. I hear that Tony has a Supra now and that it's pretty stout.... Could be a good test for me.

 

well, i might be able to go tonight if the landscaping guys hurry up- currently my garage is blocked my a ton of sandstone. theyre coming out tonight, so hopefully it will be moved- yeah, tony got a nice red 98 poopra. call me if you remember when u head out ! !


thanks