408 Iron Block with what turbo??
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I have finally decided on getting a built shortblock and after much deliberation, went with a 408. The shop where my car is at told me to go with a custom 72mm turbo, which was recommended by their turbo guru at Borg Warner. This is a 99.5% street car so they are going for quickest spool as possible. Doesn't this seem too small for this big of a motor? I don't want to have a turbo that spools up great, but then falls beyond its efficiency level in the upper rpm range. What do you guys think? Is this a little too small for a 408, or will this provide great spool as well as a strong upper end?
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72mm is way to small for a 408.
I wouldn't do anything smaller than a t6 flanges 88mm like the s88 or gt4788.
You need more than the 72mm can flow no to mention serious back pressure issues.
I wouldn't do anything smaller than a t6 flanges 88mm like the s88 or gt4788.
You need more than the 72mm can flow no to mention serious back pressure issues.
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Originally Posted by cablebandit
s488 or s88 with a 1.10 t6 exhaust housing
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Originally Posted by geegro05
yeah but when would the turbo spool up with that big of a turbo? Did I forget to mention this is a GTO (heavy as hell) with a 6-speed and a rear mount turbo? I need one that will spool up good in lower to mid range rpm, and still be able to breath up top.
No one has tried to run that large a turbo in the rear of a street car.
a 76 will have issues feeding the car, i wouldn't want to think about a 72mm
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One of our S88's will make big power for you. Also we have a used one that has been turned in, freshened and is ready to go for a fraction of the price of a new one. Customer has now gone with one of our bigger series units that is due out in fall which he will be testing for us.
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I like my garrett gt-4508 81mm, ball bearing and makes boost as soon as you push the gas....it's almost like a nitrous car....and it's suppose to support 1250hp....just a thought....
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Originally Posted by red beast
I like my garrett gt-4508 81mm, ball bearing and makes boost as soon as you push the gas....it's almost like a nitrous car....and it's suppose to support 1250hp....just a thought....
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Originally Posted by Alex @ CMS
you might want to rethink your combo.
No one has tried to run that large a turbo in the rear of a street car.
a 76 will have issues feeding the car, i wouldn't want to think about a 72mm
No one has tried to run that large a turbo in the rear of a street car.
a 76 will have issues feeding the car, i wouldn't want to think about a 72mm
For MAX spool on a rearmount car, do not use headers or cats. A shorty header at the most, use a smaller dia pipe depending on power level. a single 3" will flow great but take longer to fill up. Wrap the exhaust with heatwrap! we picked up alot of spool and it lost a bunch of heat from under the car.
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Originally Posted by Jake@EPP
We ran a 76GTS outback on a camaro with a 408 low ci. It did spool late but that was expected for a larger outboard. However, on the customers previous 382, the 67mm did 708rwhp on 13.5psi . This new gts does 670rwhp on 11 or so psi.
For MAX spool on a rearmount car, do not use headers or cats. A shorty header at the most, use a smaller dia pipe depending on power level. a single 3" will flow great but take longer to fill up. Wrap the exhaust with heatwrap! we picked up alot of spool and it lost a bunch of heat from under the car.
For MAX spool on a rearmount car, do not use headers or cats. A shorty header at the most, use a smaller dia pipe depending on power level. a single 3" will flow great but take longer to fill up. Wrap the exhaust with heatwrap! we picked up alot of spool and it lost a bunch of heat from under the car.
as far as large turbo i ment a t6 flanged 88mm.
What happened to all those sts cars that got the MPS wheeled 67/76s?
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Originally Posted by DrTurbo
One of our S88's will make big power for you. Also we have a used one that has been turned in, freshened and is ready to go for a fraction of the price of a new one. Customer has now gone with one of our bigger series units that is due out in fall which he will be testing for us.
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Originally Posted by Jake@EPP
We ran a 76GTS outback on a camaro with a 408 low ci. It did spool late but that was expected for a larger outboard. However, on the customers previous 382, the 67mm did 708rwhp on 13.5psi . This new gts does 670rwhp on 11 or so psi.
For MAX spool on a rearmount car, do not use headers or cats. A shorty header at the most, use a smaller dia pipe depending on power level. a single 3" will flow great but take longer to fill up. Wrap the exhaust with heatwrap! we picked up alot of spool and it lost a bunch of heat from under the car.
For MAX spool on a rearmount car, do not use headers or cats. A shorty header at the most, use a smaller dia pipe depending on power level. a single 3" will flow great but take longer to fill up. Wrap the exhaust with heatwrap! we picked up alot of spool and it lost a bunch of heat from under the car.
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Originally Posted by geegro05
Sorry for my lack of turbo knowledge, but what is meant by the outboard? I was hoping the 76 would spool great on a 408, so this outboard thing kinda confuses me
Also, the cats were taken off like 2 years ago, we arn't running headers, and we have new stainless steel exhaust wrapped from the manifolds back and sprayed with that black stuff.
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Some STS kits dont seem to want to follow the rules while others make great power.
JDz28 made like 600+whp on a 347 and pump gas no meth.
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Originally Posted by markp03
I will be running a 408 with a t6 76mm turbo, front mount of course. I will let you know how it goes. Motor should be here in 2 weeks or less.
Let me quess..... a GT42-76mm Unit with a T6 Flange???
I bet shes's out of steam by 11-13 psi.....
Extreme back pressure with that turbo......
Kyle
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Originally Posted by NA$TY-TA
Let me quess..... a GT42-76mm Unit with a T6 Flange???
I bet shes's out of steam by 11-13 psi.....
Extreme back pressure with that turbo......
Kyle
I bet shes's out of steam by 11-13 psi.....
Extreme back pressure with that turbo......
Kyle
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So I guess Jose talked with my shop and he recommended to them a TC76. That sounds a little better in my book. One question I have is what is the deal with the $100 race cover worth 75-100hp gains? Is this legit? Also, would it be worth it to get a ball bearing turbo?