Chubby

The shop doing installation put on stage 3 heads instead of stage 2. The car is a 2000 vette 6 speed, 3.42s. LS6 intake, LS1 edit, LT headers 1 3/4,Touring exhaust, 30# delphis, 178*. The car dynoed at 403 RWHP (at 6200 RPM), 380 or 388TQ. I am not getting charged any extra, but I am concerned that the exhaust velocity is being slowed down too much and that this may be leading to decreased exhaust scavaging.

I have a stock TB and pulley, but do have an ORP. With this combo I was hoping for 420- 430 RWHP. Do you guys think this is an acceptable setup? Or should I insist upon st 2 heads and new cometic gaskets/ ARP head bolts? I spoke with Craig at GTP and he said that I should not loose power, but from what I have read stage 3 heads are only for 4.00" bores and up. If I keep the heads what are the ramifications?
The work was done by a reputable forum sponsor.

Thanks in advance

Greg

VINCE

iTrader: (1)

Why did you go with Stage 3's in the first place? I agree your #'s should be higher.. What size valves are in those Stage 3's? If you have the opportunity I would go with Stage 2 heads.. That's just my opinion..

Chubby

I wanted stage 2s. It was a mistake on the shops part, not myself or GTP. 2.05" valves.

Chubby

I wanted stage 2s. It was a mistake on the shops part, not myself or GTP. 2.05" valves.

BTW, I do not plan on boring or stroking it any time in the for seeable future

Greg

VINCE

iTrader: (1)

Have the shop correct the error..

sr71bb

iTrader: (3)

I agree. Go back to Stage 2's. I make 416 RWHP, 401 TQ with STOCK LS1 heads and SpeekTek F1 cam (230/226, .591/567). Estimated HP with Absolute Speed Stage 2 heads in transit should be 460/465HP although I will admit the motor is a bit of a freak by probably 10-15 HP.

Most porters get high flow numbers and sacrifice low to mid range numbers by enlarging the runner volumes in the head WAY past stock volumes.

Chubby

I recieved a fax of the dyno sheet today. 403 RWHP@6200 and 381TQ 4600-5100. HP and TQ intersect just short of 5500 rpms, correct me if I am wrong but I thought they were supposed to meet in the neighborhood of 5200 rpms. I am having trouble scanning the results into this reply. If anyone could help me out I would e mail the file.

Any feed back is greatly appreciated.

Greg

H82BBad

auto or manual car what headers? full list of mods please

XtraCajunSS

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Chubby:
<strong>I recieved a fax of the dyno sheet today. 403 RWHP@6200 and 381TQ 4600-5100. HP and TQ intersect just short of 5500 rpms, correct me if I am wrong but I thought they were supposed to meet in the neighborhood of 5200 rpms. I am having trouble scanning the results into this reply. If anyone could help me out I would e mail the file.

Any feed back is greatly appreciated.

Greg</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">HP and TQ will cross at 5250RPM if they are both on the same scale. Look to the right and left side of your graph. I'll bet the scales don't match. Ask for a graph with forced scaling and you should see the proper correlation.

Shane

Angry'Z

maybe I missed it but I didn't see a cam in your thread. Should I assume that you only changed the heads? GTP stage 3 heads are different from stage 2's in the following ways 1)bronze valve guides 2)Ti retainers 3)the runners and chamber are hand polished. The size of the valves are most likely the same as stage 2. If craig told you that you won't lose any power you can pretty much take that to the bank. If anything, your flow numbers will be better due to the hand sanding that is involved. I have been to his shop and seen a set of stage 3's <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> they are like glass. Has the car been tuned? Maybe the cam isn't right for the better flowing heads? Craig should be able to help you out as far as cams go - I mean that is what he does.

Michael

VINCE

iTrader: (1)

TR224 cam..

Chubby

H82BBad,
The car is a 2000 corvette with a 6 speed, K&Nn descreened MAF, LS6 intake, TR224 112 with .561" of lift, GTP Stg 3 heads with Ferea? 2.055" valves, Stainless works 1 3/4" long tubes, Bassani offroad X-pipe, B&B touring exhaust (RESTRICTIVE) and LS1 Edit.

Shane,
you are right , HP and Tq do not correlate. Thanks for the insight.

Michael, TR 224 cam.

TB is stock as is the underdrive pulley. No exhaust cut outs. I spoke with Craig at GTP, he seems very straight up and was very helpful. He did not thnk the larger valves would hold me back at any point on the dyno, and thought that more HP would be found with more time dyno tuning.

Greg

JC00SS

Sounds a bit low IMHO. Check my sig. The dyno was done in 98*heat.

TimZ28

Before anyone starts swapping heads I would first get the exact state of the tuning. By this I mean...

- Timing
- A/F ratio as reported by a wideband

You said you have 30# delphis and a descreened MAF. This is really an unnecessary combination of modifications and will make tuning much more difficult. Post some A-tap data if you can.

Tim

kick_*ss

iTrader: (1)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JC00SS:
<strong>Sounds a bit low IMHO. Check my sig. The dyno was done in 98*heat.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have to agree, I am still on stock heads and have the TR224/.562/112lsa CAM, Stock MAF, FLP LTH, SLP D/D, ASP pulleys, and before tuning with LS1Edit I have RWHP Max Power = 368.8, Max Torque = 353.3.87, and this was still with the Rev limiter at 6250.

blownlx

your hp and torque does intersect at 5250. Look at your hp and tq and they are just scaled differently. hp is just an eqation derived from torque and rpm

White98Z

iTrader: (3)

I have pretty much same set up numbers in sig

Chubby

HP and TQ are scaled differenly. From the numbers you guys with similar set ups are putting down I would say that I am on the down side. Larry recomended replacing the coil packs (which I had sent with the car). For some reason the TQ curve dips 25 ft-lbs between 3800 and 4500 rpms and it starts to fall off at 5250. Hope the new coil packs remedy this.

I consumed oil for about the first 15 to twenty thousand miles. I have 27,xxx miles now and hardly any oil consumption now. Redline 5-3o in the winter and 10W-30 summer. Wonder if carbon build up could be causing a problem.

Chubby

I forgot, A:F is 12.8 to 13.

VINCE

iTrader: (1)

My question is..... You went to a shop and they were suppose to install Stage 2 heads and made the mistake and putting Stage 3 heads on. I would make them correct the first mistake and then go from there.. Why try to tune Stage 3 heads when you obviously need to put the Stage 2 heads on that you paid for? Get what you paid for.