Well you got to think about why is it happening and what can cause it. The only to things left to check are 1)Compression, 2) Cam timing. You have already exhausted every other idea. It has to be something serious b/c no little thing should make the motor lose that much power. You should have somewhere in the area of 380rwhp. You said you drove the car 250 miles and then you went to the track, that seems like a short break in time before running it at a track, I know you only shifted at 5500 but still. And how did you break it in? Was that 250 hwy miles or stop and go miles. It needs to be stop and go so the motor is always changing rpms, thats what seats the rings. Did you use synthetic oil during break in? You seem smart enough not to. Just some Ideas. Then there's the chance of the cam being ground wrong which can happen. But if you get it that far apart then send the cam back to comp and they should check the grind for you to see if its off. Or just order another one. B/c it might be highly doubtful comp will help you if have driven this car 25k miles with the cam even if its the wrong one. And something had been wrong from the get go b/c 107 trap speeds is about ~310rwhp. My car did 106 in the 1/4 and I have never dynoed it but I am sure it had about 280-290rwhp from my times and speed. You have done everything else, now do a compression test. And did you ever check the fuel pressure @ WOT? Even with the new pump check it, at this point nothing is worth overlooking. For some fluke you fpr might be dirty or something crazy. HTH.

Trent

 

And try another dyno in Turbo_Z's car. Its like getting a second opinon from a doctor. I know its far but just so you know how far off the one your working with is.

 

It might be blow by, pop the oil cap off while the motor is running if smoke comes out then the rings arent sealing to the walls. May wanna try a leakdown just to be sure.



It wont open the valves all the way. Like having a cam with .600 lift with 1.6rr only have .570 b/c the valves arent adjusted right. If they are comp "R" a 1/4 might be to much past zero lash, try an 1/8 or some people just leave them at zero.

 

BLKLT1Z28- I only went 250 miles because i was told the motor probably only needed about 100-200 then change the oil and it would be good to go. I was told because the tolerances on this motor are good enough it doesn't need the long 500+ mile break in. The break in was mostly city but with a few 20+ mile trips out of town.
Ok well i think i'll plan on actually buying a Fuel pressure gauge and checking it this weekend. I'll also try to do a compression test. Thats gonna be such a PITA with the SLP headers. Then that'll narrow it down quite a bit.

 

Well, no break in is neceesary on hydraulic roller cams, so thats out the window unless he had a new shortblock done. If he had a shortblock done, then break in is necessary. Rockers too tight means they stay open too much and rockers too lose means they wont open enough. Definitely hit another dyno, but track mph still stinks either way. What does AI think?

 

That has occured to me before. Ill try 1/2 past to see what happens or find some R lifters. Im sick of throwing money at it.

About track times. I have ran a best of 13.058 at 108.5 with 2.166 60' and shifting around 6k, 3.42 gears. My mph seems a bit low but this track is kinda slow and its at 1100 ft.

 

My car doesn't huff any smoke at idle and doesn't lose any oil during the time between oil change. I've run it with the valve cover cap off and no smoke and i even checked out of the dipstick tube as i've heard of that problem with others. I don't run synthetic oil just the regular stuff.

In reply to RealQuick yes the track time wasn't the greatest but a friend went to a diff track with nothing else and gained 4-5mph with the exact same setup. It is just known as a **** poor track but you have to take what you can get in this area unless you want to drive 200+ miles to KC.

 

Sounds like your track stinks. best bet is to hit another dyno or a different track.

Who is faster in a race, you or turboz?

 

I see from your last log that you are only pulling around 280 gms/sec through your MAF. This only equates to around 310 hp or so at the wheels. To make 380 rwhp, you should be pulling around 350 gms/sec of air.

You need to find out what is limiting the airflow of your engine. You either have a severe restriction in the exhaust (your MAP values seemed ok), or you have a problem with the valvetrain. If you are sure your valvelash is correct, I'm going to guess your cam was ground wrong or you installed it a tooth off.

This is assuming you have a stock MAF and it's functioning correctly.

 

Ok thanks Rich. I'll look into that also then. Brad AKA (Turbo_Z) had told me that you take the grams of air flow/sec *1.1~ hp, but the odd thing is that on some of our runs the gms/sec would vary by up to 20 but the hp level wouldn't change.

 

Actually the last and only real time we ever raced i won.

 

MAF readings could be low if you have a vacuum leak...

Do yourself a favor, grab turboZ's MAF and try it on your car to see if you still get the same flow. If not, your MAF is off, plus you might still have a vac. leak if the numbers are still low.

 

I agree that a vacuum leak can cause the MAF reading to be low, but since his power output so closely matches the airflow his MAF is reporting, I ruled it out. Plus, I think his car would have problems idling with that large of a leak. His idle vacuum is around 60 KPa which around 12 in/Hg. That seems about right for a cam that large. What vacuum do most people see with that cam?

He banks have even O2 readings and its hard to get a manifold leak that doesn't skew the numbers to one bank. His injector DC is very low for the power he should be making, yet his O2 don't indicate he is running lean. This also suggests his MAF is reading correctly.

With 30lb SVO injectors, I see a DC of 70% at 6000rpm with MAF readings of 340. His injectors are only seeing around 55%.

 

I'll add my couple of ideas.

Cheap and easy:
Your website lists a borla (w/ electric cutout) and midlenths as your exhaust. That is crappy for performance right there. What are you using for a Y pipe? A fairly cheap mod that should help some...a cutout closer to the merge of the y pipe. I picked up 30rwhp+ from cutouts near the header. The overall setup isn't very condusive to hp, but it would be expensive to replace/upgrade.

If you have comp Rs at 1/4 past they are too tight. Mine are at 1/8 to 1/4 and were too tight. My car stopped pulling at 5700 when it shouldn't have. I'm going to go to 0 lash (maybe just a hair past to keep them a little quite). Lash can have a big effect on powerband and upper RPM stuff. Loosen those up a bit.

Have you double checked your TB is operating correctly? Mine was a PAIN to get even somewhat liveable. It wasn't opening fully and sometimes stuck open. Check that its opening 100% and that the TPS sees it as 100%. (Simple and common sense but easily overlooked).

Sorry to hear your still having problems...once you get it running correctly it will be a beast. Don't give up on it.

 

Well then, Hmmmmm. I know what its like to have a crapy track, so lets through that out of the equasion not to mention your up there compared to me (1100ft, I'm sea level) Do you have your egr plates on your intake blocked off? Or do you have to deal with emsissions? I dont here and I blocked off my egr but left on the pipe that went to the exhaust manifold so it would pump exhaust into my intake and it had no place to go b/c the egr valve was gone. Then I finally closed up the tube to the exhaust and sealed the intake and it ran good again. But here in FL we have no emmisions But if you do maybe you can check to make sure its all working properly. I am just trying to think of something that hasnt been thought of yet, to save you from tearing into the motor to get the cam out. If the compression tests comes back bad then chase it with a leakdown test to see where its going.