STS Kit - Stock cast manifolds or Headers
STS Kit - Stock cast manifolds or Headers I'm trying to decide what to put on the car, I have brand new coated pace setter long tubes and I have some 2000 cast iron manifolds. Neither are on the car so I can choose which ones to put on. The motor is 370 cu in, 8.6:1, completely forged plan on running 10-15 psi and will be a daily driver. Looking for anywhere from 500-600 rwhp. I want good boost response and spool up. The turbo is a Master Power T70 with a .81 housing. I'm in California as well with some strict smog checks. I'm thinking the headers will be a problem at smog time or can be, will hurt my spool/response time BUT probably give me more top end breathing. The cast manifolds will be fine for smog, probably hold up better in the long run and give a better spool up/street manners. I may be off base but does anyone have personal experience with this. Let me know what you think. Thanks
We have worked with both. The manifolds are fine and might work better for you because of smog. The headers could work for smog but could leak. We havent had leaking problems on our LS1, and we dont have to worry about smog. An install on an LT1 did have have header leak problem, but then again he had a leak problem before. You could also think about ease of plug changes, and money might be better spent else where. Comes down to preference.
What about the performance aspect of it, do you think the headers increase the lag and slow the velocity since the tube size is bigger? Or do you think the manifolds will limit the top end but give more bottom/mid range and if so any estimate. That would be a very interesting back to back dyno comparision. Thanks for your help - Dave
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I'd stick with stock manifolds personally. I have tried both and didn't notice any difference between them. If you really think about it, most front mount turbos have some pretty restrictive looking manifolds yet they still make big power. 
I would just go with the stock manifolds. Headers are not significant on the STS. As far as the t-70, you should reach your hp goals w/o much of a problem. I put a GT-70 on a 408, but with a .96 housing and it spools great. I would see what happens with the .81 before making any changes.
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12 Second Truck Club
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From: Sacramento, CA
In theory yes it would but in practice why bother.. It owuld be costly and ugly and probably wont net much of a result. If the turbo is sized properly then lag wont even be an issue.
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12 Second Truck Club
Joined: Feb 2002
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From: Sacramento, CA
Originally Posted by TurboBerserker
LOL, Erik and I are prime examples of turbo sizing. Just the lil bit of difference between his 6.0L and my 5.3L makes a world of difference. We both have the same turbo and system yet he has almost no lag and I have a boatload.
*I wanted more top end right now and will be doing a 6.0L when this motor dies*
Originally Posted by trtturbo
I would just go with the stock manifolds. Headers are not significant on the STS. As far as the t-70, you should reach your hp goals w/o much of a problem. I put a GT-70 on a 408, but with a .96 housing and it spools great. I would see what happens with the .81 before making any changes.
I have been hoping for some #s from that car, but issues keep coming up. When it left my shop it was making boost. After the IC was installed it wasnt. He brought it back and we got it making boost again and changed the boost controller they installed to ours. Now there is a coolant issue. He did say that before that happened, it made alot more power that it ever did with the 2 stages of nitrous and that was 530rwhp.
Maybe we will get some #'s in a week or so.
Maybe we will get some #'s in a week or so.
