Ok guys.. I have been playing with this idea for a while now. My drivetrain is built for it (other then clutch). So here is the rest of my idea...

A built iron 408 up front... lots of folks are doing these so I am not going to get too far into that. Needs to be capable of ~1000 hp. Fuel system will consist of something similar to the Nasty performance Stage 3 street kit. Not sure what size injectors to go with... I am thinking 65# or more.

Turbo setup.. This one is hard. I would prefer that people don’t bash the STS choice, instead if you have ideas or concepts to assist then chime in. First we would clean up the piping and routing by doing Batt relocation... some custom piping by Billy at STS will most likely be the answer here.

We have had some good thermodynamic conversations about the effect of exhaust gases as they cool leaving the engine, what volume efficiency and speed effect that may have at the rear of the car vs. the front and how to maximize the compressor maps of the right turbo.

I am limited by a couple key factors…
1# the actual size of the turbo must be able to fit under the back of the car…. So no 88’s, hell even a GT-42 76 is too big. After some good convo with Jose I believe that the 76GTS is the largest turbo housing that we can fit under the rear of the turbo add the 80mm upgrade and we are in the house of 1200HP for a front mount, ???? for a rearmount? What do you guys think about the AR? .81? .96?

2# is that I need to insure that the pressure to the manifold does not become greater than (Please insert # here)… I think its 2:1 but I cant recall from my convo with Jose. This is a challenge with the factory STS piping (insure it is capable of flowing the necessary CFM) and the joints (don’t want to blow the pipes apart every time I mash the gas).

Well… I have lots more to add… but I am out of time for lunch. So I am going to head back to work. I think this is enough to get responses and information from some of you turbo guru’s.

 

id go with the .96 AR to help combat backpressure which shouldnt get greater than 3:1 i think it is

 

**** there is a vette guy with a 106 stuffed under the bumper

 

With the 408 and auto, go .96A/R. We have made some pretty good numbers in the past. Some of the lag and top end suffers, but it's still enough for 9's.


Jose

 

I think the hard part would be really hooking the car. The really quick cars are building boost at the line and I'm not sure how that would work with a rear mount.

 

I'm kind of curious why your trying to save a few dollars while building a 9 second car?

 

Here is what you are refering to......lol. Biggest waste of turbo possibly ever. Whoever picked this unit has absolutely no clue how to pick a turbo.

 

We do it with a 2 step. It will work with a rearmount as well, but you have to retard the timing some additional degrees to get that added heat to the unit.

 

Car already has suspension, 9", and a 2 step. If I remember right he was already cutting some 60's in the high 1.5 range.

 

I think your going to need some larger then supplied up-piping. Might look into oval tubing since the areas the STS route get pretty tight clearance wise with the small tubing they provide. Also, we had to weld a bead around the piped on the car here or it would simply blow the piping off at the connection by the LCA. Good luck though.

 

Actually there are three Corvette guys running rear mount singles behind high dollar 427's. Two are very high dollar. 1,500 RWHP+ and will run low 7's. All three have run 8's on their previous setups on a 10.5 tire and full interior car.

The are number of other Corvettes (six to eight) 402-427 that running twin rear mounts 800+ rwhp.. Four I know are going to be running 20+ psi..

 

Jose... thanks for the quick chime in.... You are my sourse for most of my turbo info. When we talked you told be about your concern with manifold pressure being too great. Could you elaborate some?

CAT3... my concern exactly.... I am trying to figure out how to get a larger flowing piping from the back to the front.

Buyamerican... wow... those are some numbers I have never heard. On rearmount setups?? 7's??

TRTurbo (Billy)... My best 60' is a 1.51 on shitty factory wheels and ET streets. Have you had any luck with a way to get larger CFM piping on the cold side?

Boostaholic... not doing it to save a few bucks. I want to have a 9 sec turbo car that I can drive 2 hours to San Antino with the AC on... race.... then drive home. A true daily driver.

RyanJ... I have lifted both wheels in the air on launch... the Harlen 2-Step works well with a strong clutch and 5k dump under load

Soooooo the big question.... Has anyone done this yet? Anyone have some suggestions on what I need? Any advice? Turbo guys I would still love some input on the best turbo for this application.

 

I've got backpressure issues with my R-Trim wheel, the issue is I can't get enough pressure LOL I'm running a .70 a/r and it spools fast to 10-11psi then creeps to 13 but thats it, even with the wastegate unplugged and the top port sourced to boost to hold it shut. On the .84 housing it only makes 6 psi.

Distance = more time to cool =cooler exhaust = dense = less volume.

I'm probably one of the few guys complaining about not enough back pressure LOL I want 20psi dammit! At least 15 for now.

The strange thing about my setup is how fast it makes the boost, even on the .84 housing. Gets right up and then just sloooowly climbs.

 

Zombie... that is a lingering fear I have. I want to ceramic coat the whole hot side to keep as much heat in to the turbo as possible. Thought about wrapping it.. even putting a blanket on the turbo... anything to max the temp/velosity at the exhaust side of the turbo.

 

Hmm never seen or heard of any of those cars. Fastest C5 out there is Paul's Z06 that is well known on corvette forum. As for in the 7's with a single rear mount.....maybe 1/8th.....but 1/4 mile, I'll have to say

 

BTW, I have been on the corvette forum for a LONG time, the most I have seen an LSX engine do on that forum I believe 1320 rwhp done by a modified P.T.K. kit with twin custom 70mm turbo from Jose@ Forcedinductions.

 

You are uninformed so I would not prematurely draw conclusions. Most of these cars have been on track for last few years.

Cartek; Paul Z.(front mount(1,150 rwhp)) & Mike (single STS rear mount, now 900+ rhwp) will race against them.

Brent (runs with Cartek) also to my understanding is putting together a 7 second ride.

Two guys who have had work done by Vette Doctors (Paul and Bill)
Paul was well into the eights on his previous setup. Right behind Paul.
That setup looks really mean. Both setups are rear mounts. 427/402

Silas, who is getting his car done at ECS. 427 STS TT
ECS also has two (402/427(1200rwhp) Novi/F2 cars that should both push eights (low nines now) as well as well another new Thumper front mount 427.

There are half dozen other rear mounts as well pushing the limits.

Don't bring a knife to straight line gun fight.

 

Have they already run a 7 sec pass, or are those bench racing times??

 

Buyamerican... So who are the two 1500+ RWHP single turbo rearmount cars? Are they F-Bodies or Vetts?

 

Your original post said 3 rear mount cars already running 8's and 7's . None of the cars mentioned are running anywhere near 7's, and none close to 1500rwhp. Heck only Casper has been that high, and in a C5 only the P.T.K / custom kit has done 1300+. I guess bench racing is good enough on the internet.