need help on turbo sizing
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need help on turbo sizing The setup is a 370 iron block, 8.5:1 compression, 6 liter heads, custom cam. I am looking to run 14-15 pounds on the street, and 18 pounds at the track (with race gas). My initial thoughts are a gt-67, but I don't want to run out of turbo. I would like to make full boost as soon as possible, but again, I don't want the turbo to fall on it's face before I hit redline (about 7300 rpm).
So what size turbo, and what a/r does everyone think I should go with?
So what size turbo, and what a/r does everyone think I should go with?
First of all which kit are you going to use? If its custom, then the 76GTS or GT42-76. If space is a concern, then 76GTS. I would say T88, but you want quick spool so thats kind of out. As for the 76GTS, .96A/R all the way. Also PSI is not a good way to dictate a setup. A 346 at 18psi and a 408 at 18psi are moving 2 totally different levels of air.
Jose
Jose
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I understand what you are saying. See my sig...this is your favorite turbo setup. 
I was thinking about the 76's but wasn't sure if it was overkill. Do all of your specs stay the same knowing it's a rear mount?
Thanks Jose.
I was thinking about the 76's but wasn't sure if it was overkill. Do all of your specs stay the same knowing it's a rear mount?
Thanks Jose.
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From: st paul mn
i seen some pics on here of the phamspeed sight w the budget kit. and the web sight is down right now but w/o intorcooler runs 2500. i would like to go w i/c and the turbo under the cars hood but i want to spent up to 5 for the set up and tune if possible i thought it was a t60 turbo
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Yes power is the way to select the unit. I can say this, a 70 will not support 18psi unless your running a big 70 with a nice size A/R, but it will hurt spool up which already suffers a little with the rear placement.
Jose
Jose
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Jose, what your saying is what I'm concerned with. Could I go with a 76, but smaller a/r? I don't know a ton about turbo sizing, which is why I posted this. But, I am assuming the smaller the a/r the quicker the turbo would spool, but you run the risk of it falling on it's face on the top...is that right?
Thats right...thats part of the reason why a rear mount system doesn't work to well with big turbo setups. You have to run a small A/R to bring up the boost, but end up then choking the system up top. Just a flaw in the design. Doesn't mean it can't work, but its just not the best option for what you are wanting to do.
Jose
Jose
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I hear ya...the good thing is that the new motor will rev well over 7k rpm. So, if I have to run a larger a/r, at least I'll be able to stay in boost for a longer period of time. Thanks for the info though.