In regards to this thread.

I just got an E-mail forwarded from a friend.

Yes, Bryan from PCMforless will be at my local machine shop Wednesday doing dyno tunes.

I made a new thread so as not to confuse the two subjects and make a place to post the Dyno gains if any.

Should be really interesting to find out why my car is so slow. Is it me or is it the car.

 

Sounds like a plan.

 

Looking forward to seeing the results!

 

I am still not convinced that tuning is going to gain you that much over the stock LT4 tune which is VERY compatible with the Hot Cam.. matter of fact, that was the original cam GM planned on using in the LT4 motors. the tuning is very very close from personal experience, not alot to be gained.

that being said taking a car with a mechanical fault to get tuned is wasting money as tuning won't correct it. but as sitting the way yours is performing poorly I suppose it is worth a shot.. but not something I would put alot of hope in.

Chris

 

PCMFORLESS = GOD !!!

Alvin made my car go from mid to high 13's to consistent 12.80's and gain 10mph in the quarter after my heads and cam swap. This was with a stock converter, 2.59's and shorties with stock exhaust minus mufflers.

Good luck,

Dave

 

Well WTF do you suggest I do? Tear my motor down on a whim hoping something jumps out and bites me in the *** with no direction?

From the way it runs on the street I can't pinpoint a sigle thing that makes say "well that's gotta be a problem" on the contrary it's performing rather well, smooth acceleration, 4th gear is wicked as hell, put your foot in it and you get that sucking feeling in your back. First is just murder on the hides.

I want to see the RWHP numbers and Tourqe peak first, I'm not going blindly chasing non existent problems, I want some data to go on. Tuning is just a side benefit to all this, it can't HURT anything.

 

If nothing else, hooking his car up to all the technology that Bryan will bring to bear might just help find the cause.

 

Exactly. Bryan won't tune it if he finds somethign wrong and with the experience both of us have hes likely to find whatever has been causing your issues.

As far as the stock LT4 tune being close.. The last one I did picked up 23 hp on a bone stock car. It was on a dynojet used by the biggest nascar team out there. so you be the judge.

 

I think having it on the scanning gear and on the rollers will tell you what is going on, and certainly won't hurt.
The calculations the ECM makes in closed loop regarding BL, through VE tables etc. has an effect on the calculations made in the PE mode (power enrich @WOT). There could be a few different things going on that you can't "see" in the tune. It is my understanding that a stock GM tune is around + or- 10 regarding BL 's etc. While the ECM is still in control, it takes a lot longer than some believe for the ECM to compensate, and does change things.
As to another suggestion I did read, I think you would know if there were any mechanical issues. MO

 

I'm looking forward to your follow up post!

 

Bogus,

I agree.. as I stated with how the car is running, I think if there is something found with the computer plugged in it is great. my point was that if there is a mechanical problem and all they planned on doing was tuning it... they would run into a fit trying to dial it in. I have tried to fix issues with tuning only to find out that there was something wrong elsewhere that needed to be addressed. a broken valve spring to be exact.. something so small screwed with me for 3 weeks until I finally found it.. the inner spring on a set of dual springs broke tore a seal up and was passing oil but not enough to notice.. it also would occasionally hang the vale ever so slightely. I was amazed I didn't loose pushrod from a binding experience.

I want this car to run awesome, I have read through several of his posts, I don't always do that, more heads are better then one, I understand his frustrations. We have all been there. to me tearing one down is like changing oil to someone else.. if it feels like a monster of a job I understand his hesitation to check on everything. I wrote a huge writeup on setting the blancer to TDC toi verify cam timing. this would also be something that PCM4less could use to check with their software onthe dyno.. if it works out great peace of mind.

I in no way wanted to add fuel to the fire and it appears I hit a sensitive nerve and for that I apologize.. I won't interfere or offer help. and I still hope it gets resolved.. it is a beautiful car and a nice packege, I hope ALLT4 gets her dialed in and all works out well in the end.

Off my soap box.

CHris

 

Bogus,

I agree.. as I stated with how the car is running, I think if there is something found with the computer plugged in it is great. my point was that if there is a mechanical problem and all they planned on doing was tuning it... they would run into a fit trying to dial it in. I have tried to fix issues with tuning only to find out that there was something wrong elsewhere that needed to be addressed. a broken valve spring to be exact.. something so small screwed with me for 3 weeks until I finally found it.. the inner spring on a set of dual springs broke tore a seal up and was passing oil but not enough to notice.. it also would occasionally hang the vale ever so slightely. I was amazed I didn't loose pushrod from a binding experience.

I want this car to run awesome, I have read through several of his posts, I don't always do that, more heads are better then one, I understand his frustrations. We have all been there. to me tearing one down is like changing oil to someone else.. if it feels like a monster of a job I understand his hesitation to check on everything. I wrote a huge writeup on setting the blancer to TDC toi verify cam timing. this would also be something that PCM4less could use to check with their software onthe dyno.. if it works out great peace of mind.

I in no way wanted to add fuel to the fire and it appears I hit a sensitive nerve and for that I apologize.. I won't interfere or offer help. and I still hope it gets resolved.. it is a beautiful car and a nice packege, I hope ALLT4 gets her dialed in and all works out well in the end.

Off my soap box.

Chris

 

I's all good, I didn't mean to sound mad. I'm just playing it by ear here, I was planning to have the car tuned not because of **** poor driving at the track or slow times, I just though it would be a good idea with those mods.

I didn't plan to have it tuned this soon, Bryan just happens to be in the area that day so it really couldn't work out better. What better way to see if my driving just sucks or if the car is really down on power?

Maybe there is something wrong but I'll be damned if I just tear things apart chasing my tail. Give me a graph while I have the chance type thing.

Patience Danielson, it'll all work out.

 

I think you are on the right track.. and you are not a bad driver.. you kept the car moving nicely.. except for that hiccup on the 1-2 shift, but if that was a one time thing I doubt it would have showed much difference. my exwife was able to pull the same MPH in my car that I did with slower ET's.. because the power was there.. usually a slower et will gain a better MPH if you review many of the track result threads you find on here.

so my OPINION, is that your driving is not the culprit... although if ya keep shiufting like ya did in the vid you and Bill from ZFdoc will become pals not far from now for some synchros.

let Alvin play with it, with some luck he will fix it or find the culprit. If not drive you car down here and I will help ya find it. although if you see my heard of force inducted cars and take a ride especially in the turbo corvette.. you may have bad (Expensive) ideas upon returning home...lol

I will keep an eye out for the results!

Chris

 

Here's the results from today.

Shot of car on Dyno, big deal.


Here's Bryan himself in the cockpit.


Started out at 331RWHP and wound up at 344RWHP, the tourque was actually higher I think, Bryan said he hit the button at the wrong time or something. He'd have to explain, I don't understand all this.

For some reason the guy running the dyno thinks it's a pain to print stuff out and these are all I got. Oh well.

I found out I probably need a new opti, although it works it's a little jumpy. The graph jumps are the tires bouncing for some reason.





Again, probably best to "Save Target As"
http://www.personal.psu.edu/gls17/Dynoday/dynorun.MPG

OK, now do you all still think I should go out a start ripping it down because something is wrong? I made some mistakes at the track and that's all there is to it. Coupled with less than stellar tires it's tough.

 

Great, are you saying the tuned gained you 13 RWHP? well worth it in my book, if that's what you gained.

 

Yeah, well it's not only that but Bryan turned the idle up just a bit, removed the skip shift, and adjusted the fans for a 160 T-stat.

I was pretty happy with results and the changes made. The car idles way smoother and driveability is even improved over "good" in the first place.

I really wish I knew what the final tourqe number was, they told me and it completely slipped my mind with all the excitement.

 

if your final was 344rwhp. arent LT1's just a tad shyer on torque with the stock displacement's? so what 344rwhp/339rwtq? give or take? one would think 344whp should trap at least 111 or so. i remember in an old posts, you mentioned 105/106 mph. taking it to the track again?

 

Do you know what the SAE numbers were?

FWIW - those are pretty good number assuming you still have stock manifolds

 

glad to see ya got some power from the tune. congratulations!

how far out are you from your header and exhaust install? from experience, I have had customers gain almost an additional 30-40rwhp from a header and catback install on a top end packaged LT4. so with some tuning afterwards.. you will be ina good zone indeed! the only thing I noticed and think is a little low from your first pull is your torque.. even with the restrictive exhaust I would expect it to be a bit higher then it was.. closer to the HP figure! but again.. wait and see what a full exhaust and a new tune does for it.


with headers, you will get that torque up hopefully and push the power right up along with it!!


Chris