Since Anti-Venom was asking I guess I'll put a thread out here. I got my system hooked up with my old zz-9 cam for the lack of valve overlap and some brand new cometic headgaskets. Just a little review here's what I've got.

Previous posts on the subject:

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stage 1 http://forums.corvetteforum.com/showthread.php?t=527703

stock pass header to a 2 1/4" cross over pipe that comes into a log style header on the driver's side to the turbo, a 60-1 HIFI with a .84 divided tangential housing. Using a delta gate to manage boost. The engine is a 393ci with ported stock heads, 9.5:1 cr. No intercooler but I did have a 35 hp nitrous shot. It's all controlled with an accell Gen 7 DFI with some 72lb injectors.

I got it all togther and took it for a short spin.

-The turbo still spools way to fast. I can create boost at under half throttle and its there really quickly.

-I could feel the engine start to stumble when I crossed from boost into vaccume. I'm not sure if it was a stumble or detonation.

-Timing was set to what I had with my old Cam at WOT with a 1.5 degree retard per psi of boost.

-I was running the car very rich or so my wideband told me. I didn't have a tune for the car with that cam so I had to rely on the program to come up with a starting point.

-The intake temps were above 200*F according to the data log. And they didn't seem to want to come down after the boost was off, I might be heat soaking my intake pipes(Stainless) When I did use the nitrous I did see the intake temps drop to what they were when I first started the car about 100*F

-I did see 10psi when I slammed the throttle for a quick second.

-After a mile or two down the road I got back home to try and take some more timeing out I found oil and coolant dripping out of the head in the same place where I blew my head gasket last time. I was then done.

So the cam had some characteristics that made the boost come on different it wouldn't stay at 7psi anymore but would spike to whatever. I really can't afford to spend a grand or more on a bigger turbo that I should have on there (t76 or so) and an intercooler so I guess I'm going to switch my cams back replace the head gasket again, and stick with the N2O for now. I'm sick of working on the car, I just want to play with it for the rest of the summer. If you guys have any suggestions as to where to go from here, or how I might have screwed up, or just random questions please let me know. Thanks.

 

Turbo's too small... That's probably the reason it's spooling so quickly. You need to get those IAT's down too, time for an I/C. I would also suggest loc-wiring your heads (of course if you're shifting the gasket that quickly you've got other probs that need to be addressed).

Pulls good though doesn't it...
-Jeb

 

Actually Jeb, It didn't really pull. I didn't get a chance to send it to wot for long enough to really get a good feel for the car. I did seem like it was less powerfull but I'm guessing that is because the hesitation/detonation I was feeling.

After spending most of today thinking about it though I think I'm just going to scrap the setup and start all over. I figure since I need a bigger turbo and a bigger wastegate and an intercooler that I might as well spend the extra $300 and make me a new exhaust setup as well and do it right this time. I'm pulling the a/c off the car since the system needs a recharge and I'll get around to that about a week before I die. Now I can put the turbo where the ps resivoir is and run the down pipe where back and down where the a/c tank thingy is. I should be able to pick up an impalla LT1 header for the passanger side and that should give me room to sneak a 3" pipe right next to the engine mount up to the turbo. But this is all theoretical until I get enough ambition to rip the car apart again and try it. Maybe this winter, I need to drive it for a while. Hopefully I'll get my coveted 10 sec timeslip with the stroker and nos.

 

It didnt pull because the tubine inlet pressure was very high. I have been messing around for a few weeks with a VNt gt37 that I put on a subaru. To make a long story short, if you shut the VNT to much to try and create high early psi (more than 10 which by the way it gets by 2700) it ends up corking up the motor so much that it's sluggish even though the boost is higher. relax the vnt and it's a monster. I suspect something similar is happening to your car only you can't get a bigger exhaust housing with a few keystrokes. However you can get a 1.35 a/r t4 housing (HOT SIDE)that will alleviate alot of that backpressure for about 200 bucks. and I agree with jeb, if you pushed out a gasket that easy you have bigger fish to fry.

 

I don't think I pushed out the head gasket. I haven't had luck with the cometics that I was using, they seem to leak oil around the outer cylenders and this one just happened to leak coolant too. The reason I replaced it was because I was sick of the oil leak. I've got some felpro head gaskets comming, they should have been here on friday but oh well next week will work.

I understand about the super great back pressure messing with the engine. There's no real point in doing that though, I think I just want to get a bigger turbo. And as I stated above I think I'm going to redo the piping and put the turbo up top pass side.

Oh, a random thought occured to me today in the shower(where I think best) I messed with the delta gate spring when I put it on the second time. I let it out all the way to try and get it to open up sooner so I don't over boost and hopefully release some of that pent up back pressure. Could I have let it out all the way so it wasn't using the spring? This would leave me to believe that it would open up on lack of vaccume or just as I crossed into boost. Could this be the hessitation/detonation I thought I felt something but it may just have been that I herd the wastegate opening up and the extra noise going on and off at that point. I am running now down pipe or dump tube. Just a random thought.

 

Well, I just ordered a 1.15 a/r p-trim turbine houseing With the v-band welded on it was $130. I talked to Joe at http://www.boostedsystems.com He's a great guy and helped me with alot. He's around the forum at turbomustangs.com alot.

It should be here by next week, along with the head gasket. So I'll be putting the car back togther n/a running it for a while to break in the gasket and then slapping the turbo back on just to see what it does. It should be ammusing to say the least, or so I'm really really hoping.

 

Hell yea brother I think your on the right track. I was thinking about your head gasket problem. Cometic recommends a 5 finish on the surfaces. If your block is stock it might be to rough to seal it up. or maybe warped?