[Flyin79bird]

Just curious about a turbo selection...I just bought my old LeMans back...before I sold it it was going 9's back in the late 90's. I have the drivetrain from back then...was wondering...looking to make this a protouring car and was toying with the notion of detuning the 477 that is sitting on the stand to run a turbo setup? Won't see much track time but would like to know what size turbo I could put on this motor to achieve approx. 1000hp. I am sure the current setup...heads/cam bottom end can support the turbo...just not sure what size turbo would be needed. Remember I am looking to detune the current combo to do street driving but be able to turn the wick up at the track. Its currently a 477...forged crank,eagle rods, ross pistons(going to dish to lower comp.) e-heads (340cfm/int, 275cfm/exh) and block/heads o-ringed. Cam is a comp cams solid roller that was originally ground for nitrous w 4/7 swap...approx 660/633, 284@.050...111cl. The block is stock and filled but have seen guys make more w turbo pontiacs and have lived. For now it will have to work as it will be mostly a street driven car for now. I was thinking somewhere in the 80mm range on the turbo to start. Car is 3450 with me in it. If I win the lotto I will get a MR1 or AP block.

[Travis Q]

An 80mm turbo will definitely do the job. A cam change is in order, I would keep it fairly small and kepp the rpm window fairly low, which will help the stock block live. Another thing that will keep you out of trouble is to keep the compression ratio low, which will widen the tuning window and make the engine less detonation prone, both of which ae pluses to keeping the stock block in one piece. I wouldn't stray much above 8:1....some people will tell you to put more compression into it, but with a small cam, you won't be able to tolerate much compression due to very high dynamic compression ratios.

You might want to think about twins.....you may be able to fit two smaller turbos into the engine bay easier than one larger unit, and a lot of times the total initial cost is about the same, sometimes even less. Give me a call if you have any questions, 256-476-1053. I can also help you source some of your parts, if needed.

Travis Quillen
Quillen Motorsports Engineering
www.quillenmotorsports.com

[BruceWilkie]

http://forums.maxperformanceinc.com/...d.php?t=618082 This is a serious built 406 SBC Take note of head flow/balance similar to a stockish E head. Compression at 9:1 Cam is a Comp xr street roller 236/236 at.050 115 LSA barely over .600 net lift w 1.65 rockers.

I agree with Travis, get that compression below 8.5 and down size the cam. Something similar to Nelsons grind probably on 116 LSA because of your longer stroke. Figure around 900-1000 hp around 5000-5500 rpm is easily doable and very driveable and reasonably easy on the bottom end if you keep detonation in control.

FWIW Turbo69bird runs a 2 bolt(studded) 455 cast crank with good rods and pistons and a single T88. Stock iron heads. With a blow thru carb on a performer intake and a hyd cam(flat tappet iirc) has put his street bird well into the mid 9's. He has recently swapped to EFI and initial test passes on a very safe tune were a bit slower but still in the 9's on pump gas. He moderates the turbo forum on PZ. IIRC his motor never sees beyond 6000 rpm.

[v869tr6]

I think if you filled the block you might want to look at replacing the missing water.
My engine has about 2 gallons of filler and I didn't replace the lost volume and now all I do is melt pistons above 20psi boost.

[70 bird]

I would look into a borg warner s480 with a 1.32 a/r its an 80mm and should hit your number.

[BruceWilkie]

Originally Posted by v869tr6

I think if you filled the block you might want to look at replacing the missing water.
My engine has about 2 gallons of filler and I didn't replace the lost volume and now all I do is melt pistons above 20psi boost.

IIRC the instruction sheet for my Diamond pistons suggested different clearances for empty partial and filled blocks. Might have been the ring instructions or both. I'll dig them up. You may have other issues and/or they may be cooling related too.(I've played the "plasma spray" game a few times myself.) I'll PM you.

[jts ocd-stang]

Hey I was just wondering where you got your turbo the "Borg Warner S480" from and how much if you done mind did it cost you,as the S400 is $585.00 NEW,do they have any re-manufactured ones for sale?What type and size of POV do you run on your setup?Thanks for your time and effort for your responding.Pics would be nice as well??
Regards,
Jason

Originally Posted by 70 bird

I would look into a borg warner s480 with a 1.32 a/r its an 80mm and should hit your number.

[70 bird]

I have a s475, if I had it to do over I would have bought a s480. When I built my car I had no idea how good the turbo would work so I went with the cheap $585 s475.
fwiw.... the 475 will support more power than I can hook-up on the street.

I did a build thread over on PZ there is alot of info on my set-up in there.

http://www.pontiaczone.com/forum/showthread.php?t=20819