Originally Posted by 1989GTA

Pushrods do seem a little long. I believe stock is 7.4". The EPS camshaft going in my new 427 short block specifies 7.425". Maybe it is just a bunch of things adding up with out a magic bullet so to speak.

Originally Posted by slow trap

the tfs heads takes longer p-rods. i may be wrong but off the top of my head seems like alot of people use 7.55s on their tfs headed combos. there are variables like shaved heads,thinner gaskets, different base circles on the cam but 7.55 should be close.

Originally Posted by JakeFusion

I'm at 16.5 degrees now... adding 70cid might help swallow the overlap.

But back on topic. Something is up with that setup. I would expect just about any 416 based combo to sniff 530+ in terms of power and at least 490 in torque but would prefer to see 500+ there too.

Originally Posted by Goosecaddy05

i barely made 500 with my setup so not any 416 will hit 530+ and i dont think my build is really missing much cept for a dismal cai... although i was expecting to at least get to 530 ... that said op numbers do seem low, but who knows... i can have a 60 hp difference from going to different dynos in my town... all being dynojets

Originally Posted by Goosecaddy05

i barely made 500 with my setup so not any 416 will hit 530+ and i dont think my build is really missing much cept for a dismal cai... although i was expecting to at least get to 530 ... that said op numbers do seem low, but who knows... i can have a 60 hp difference from going to different dynos in my town... all being dynojets

Originally Posted by JakeFusion

CTS-V also eat up more power with the IRS I believe... it's a different setup than the Vette, which seems to make more power than the solid axle F-Bodies.

You're compression is also low and your headers are choking out the setup. I bet if you milled the heads and got compression close to 12:1 and put 1-7/8" headers, you'd pick up 30-40rwhp.

Hell 346s with H/C pick up upwards of 20 just by swapping to the bigger headers. I know the bigger CID would make even more.

Originally Posted by JakeFusion

CTS-V also eat up more power with the IRS I believe... it's a different setup than the Vette, which seems to make more power than the solid axle F-Bodies.

You're compression is also low and your headers are choking out the setup. I bet if you milled the heads and got compression close to 12:1 and put 1-7/8" headers, you'd pick up 30-40rwhp.

Hell 346s with H/C pick up upwards of 20 just by swapping to the bigger headers. I know the bigger CID would make even more.

Originally Posted by 74u

Hi Sam-

So you were in the same room for dyno tuning. You tuned/drove the car and gave it a pretty good once over while it was strapped. I know this isn't what you were hired to do, but I would love to hear your impression of the car and any suggestions you may have.

Do you think it's possible that the car is running on seven, or valve(s) hanging open from pushrod length, or exhibited any symptoms of a hurt motor, assembly defect? Pull no punches

All headers are hot...and since you tuned it I have gotten great gas mileage, steady 825rpm idle, and really no sign of a inefficient broken motor. My next step is compression testing. Then what? Where is my torque & horsepower?

I went to RedLine the same evening we dyno'd and made two nearly identical passes exactly as you saw the car.

92mph with some quick pedaling required on the 1/2 shift...I feel there may be 2-3 more mph in it with better traction/air...way below where I hoped to be, and unfortunately not even where I was with my old combo that floated valves.

Originally Posted by Pray

As I stated in my previous posts refering to tuning, I am sure you know your WB and dyno and tried a bunch of stuff to get the best results you could. I know the little issues with the dyno and WB of the dyno I use and how it all needs to be lined up or set up to work. I was simply trying to add value to the post analyzing what information was posted. In my experience with tuning on the dyno I use there is more to be gained than 10rw by tuning. If that was all we were going to gain with a difference of 2 points of AFR and 8* of timing then why would we do it.

Since you are basically the only person trying to help here that has actually laid hands on the car what is your opinion on what is going on. I think we all agree that the numbers are not adding up on the dyno or the track. I think you input would really help the situation here.

Originally Posted by Sam88Gta1

It appeared to be a solid engine when it was on the dyno even though it was down on power, it has a smooth power curve. I think your only option is to try a bigger header and exhaust system. I personally think its worth 20rwhp at best. Check pushrod length, at the same time check compression and leakdown. If you don't have those tools you are welcome to borrow mine.
Going to a 102mm FAST isn't going to gain anymore power over what you have now. The first course of action should be the injector change, though that isn't going to gain any power or torque.

Originally Posted by Sam88Gta1

It appeared to be a solid engine when it was on the dyno even though it was down on power, it has a smooth power curve. I think your only option is to try a bigger header and exhaust system. I personally think its worth 20rwhp at best. Check pushrod length, at the same time check compression and leakdown. If you don't have those tools you are welcome to borrow mine.
Going to a 102mm FAST isn't going to gain anymore power over what you have now. The first course of action should be the injector change, though that isn't going to gain any power or torque.

Originally Posted by Sam88Gta1

Not every car gains 50rwhp with tuning. This car only gained 10rwhp going from 22* up all the way to 30* and a/f from 12:1 up to 13.5:1. Its not always magic.