vettezilla

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I am planning on building a turbo motor for my 94 Vette. My plans are in the ball park of 800 RWHP without nitrous. My plans are to remote mount the single turbo out back for weight distribution an heat and a 355ci LT1 (I was told a 355 would be stronger then a 383 or 396 due to the location of the wrist pins)... my question is what size turbo would I need for this build is, is there any websites where I can research these kind of builds. I have a set of AFR 210 heads for this build with 64 cc combustion I believe if memory serves me correctly. Where are some good sites as well to get a rotating assembly

12sec97Z28

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Www.lt1boost.net. Not sure if he's a sponsor here or not. He was on CZ28.com. Anyway, he knows his stuff on LT1 turbos. 800 is probably doable on a 88mm but it's a lofty goal on a LT platform. Also, talk to him or someone knowledgeable about your goals.

If you want a dyno queen you can throw a huge single turbo on, make big peak numbers but not have a usable, streetable powerband. If you want a driver's car, you MAY have to sacrifice a bit of peak power but will have much more usable power under the curve. This is especially important if you are staying 355 instead of stroking it. I'm admittedly not a turbo guru yet but you also may have trouble making that power on a remote mount system. Maybe someone else can weigh in, but I don't recall seeing those systems putting up serious numbers.

I got my crank and rods in the for sale section here and CamaroZ28.com then had my builder spec the pistons for me. You can catch REALLY good deals on LT performance parts these days. Good luck on it.

Shownomercy

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Now, how come when someone else says it, its fine?

Rear mounts are lame, do not do that if you want a decently responsive system. As far as vette kits, you may be needing to find a pipe welder and make your own kit. Keep it a T4 flange, get a PT7675 or the turbonetics equivalent 7875, and you should have a nice power band.

Keep in mind you need a wastegate, blow off valve, boost controller, built trans, built rear etc etc.

I do not see how a 355 vs 383 has different qualities, but up to you, the 383 will net a better platform IMO. All about the pieces coming together in the end.

WhistlingZ

My car, 355, 9:1 compression, afr 190cc heads, baby blower cam, gt4788 front mount turbo on 15#s made 758 rwhp through a th400, 9" with Detroit locker on pump gas... Would have made 800+ but was floating valves with more boost... New valve springs going in soon..

It can be done on an lt1...

vettezilla

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What is wrong with remote mount turbo setups, is there a lot of turbo lag generally with these setups or are they inefficient or both... they sound great in theory extra heat out of the engine bay better weight balance cooler charge.

Shownomercy

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Turbos function better with heat. So ya.

96capricemgr

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Turbos are efficient because they are reclaiming otherwise wasted energy(heat) from exhaust gasses. Further away you mount the turbo the more of that energy is lost before the turbo can use it.

bufmatmuslepants

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And the farther the turbo is the longer it takes for the exhaust to spin it, and the turbo to push it to the engine, so yea more turbo lag.

vettezilla

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Another issue is there isn't a whole bunch of space under the hood on these cars and I do not want to lose AC to make it fit... I was always under the impression that if the turbo or turbos were sized properly that lag shouldn't be a whole issue... is there a whole formula when it comes to figuring out which turbo you need.

96capricemgr

iTrader: (1)

A well built V8 engine and system should have enough NA power to respond and begin getting the turbo spooled up quickly. Lag is a relative term.
In simple terms the exhaust backpressure is going to endup being higher than whatever boost you get back out of the turbo, lag is that backpressure building and the wheel on the turbo accelerating. The greater the volume of the plumbing in the system the longer it will take to build that backpressure, be it half a second or 3 seconds or whatever.