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Discussion Starter #1
Hello Team need some help with my cam selection twin 62mm LQ4 ported 317 heads already have both cams. looking for 700+whp with turbo 350 trans. Thanks

FTI 230/228 610/600 115
GT2-3 207/220 581/587 117.5
 

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since you already have both cams go with the fti, no reason to leave power on the table by running the smaller cam

unless u dont mind running a few more lbs and want a really quiet motor
 

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most would say my cam is too big but I run a 248 254 on a 116 but you better have you have low back pressure or this cam will fall on its face. twin 72's at 2900lbs no numbers yet. :smt102
 

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Its all about the EVO and IVC events. Very informative thread in the ls section on the topic.


Twins will have very little backpressure. You will be able to push the evo out approaching 60. Ivc somewher around 48 or so.
 

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Discussion Starter #6
Thanks guys what would be a good exhaust housing for this set -up, good spooling and not too much turbo lag. Thanks
 

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If a [email protected]'' cam can run 145+mph, and pull until 6800RPM in a 4900lb 4x4 truck 370CI, 317 heads and PT88/T4 I don't see why you would need more than that for under 1000HP. I've tested cams in my truck from 209~225 and lsa from 110~116 and what ran the hardest might surprise you..
 

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Wouldnt suprise me. Ive seen 218/230 make 960 to the tire.


Again its all about the EVO and IVC.
 

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Discussion Starter #9
Well the FTI cam looks big but not sure about the lag, the GT2-3 do not look like a turbo cam.
 

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What EVO IVC would your recommend for a 427 with AFR 225 heads (hand ported by Tony Mamo) and truck manifolds running a GT55-94 turbo with a 4L80E trans?
 

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Speedracer... What intake manifold are you gonna be running?


Thats a good sized turbine wheel for those cubic inches. Thats going to allow you to open the exhaust valve sooner and take advantage of a higher initial cylinder pressure to spool that turbo. i would be looking to have it up around 58-60.

If youre running a single plane carb style intake the IVC can be sooner because the IVO needs to be sooner. A super Vic on that engine would be about 45-48 ivc and a Fast 102 would be 52-55.
 

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Ok so you will want a later IVO and IVC. That intake will be what decides the Rpm limit of your motor. Prolly gonna be around 6300-6500.

Id speculate itd look something.like this. 240/244 @.050 with a 115 lsa and a 112 ICL.

I am by no means an expert. Dont take what i say as the gospel. Im just sharing knowledge ive gained thru running a handful of my own combinations and the lessons taught to me by Mark at Bullet. If youve ever had him spec you a camshaft you know what im talking about.
 

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Thanks, I talked to a guy at Comp Cams and he recommended a 232/236 @ .050 with a 115 lsa and a 111 ICL which I thought would work but I was thinking a little bigger, along the lines you are suggesting.
 

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lil john, what say you to this combo..


370
9.1:1
317's - stock w/ good springs
pro-flo xt intake
cam is a va speed vtc4


looking to run e85, but may use pump gas instead..
turbo is an s91 1.32a/r

looking for 950+ hp.
 

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I like the overall engine combo. I dont know the runner length on the proflo. It seem shorter than a fast by looking at it. The EVO is awesome. Dont understand why itd need the exhaust valve closed 3 degrees before tdc... Personally dont see any point in closing it prior to 0. With as much turbine as you have making.it a reverse split like that is pointless imo. I wouldve made the EVC 3 or 5 which wouldve put a little more overlap in it but 13 degrees versus 7 wouldnt have been a big deal.

I agree with the intake lobe duration with you intake. Your motor isnt going.to hit the wall at 6500 like it would if it had a fast on it. It should go 7000 easy. That IVC point is a little late imo with a 3.62 stroke thou. Mightve put it at 48 and shorted the duration a couple degrees which wouldnt change the rpm.capability much if any.

The guys at VS know more about LS cams than i do but the one thing i dont agree with is the EVC point and making.it a reverse split with a stock unported head. If it was something like a trickflow head that flowed more on exhaust i could fathom why it was done.
 

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Discussion Starter #18
LS1 guys are making 900+ hp with smaller cams, LQ4 should spool great and make power with the FTI. Thanks
 

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Yea but with twins you are gonna be leaving some on the table as far as spool and response with the EVO as late as its gonna be with the FTI cam.

It will work and meet your goals though.
 

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I like the overall engine combo. I dont know the runner length on the proflo. It seem shorter than a fast by looking at it. The EVO is awesome. Dont understand why itd need the exhaust valve closed 3 degrees before tdc... Personally dont see any point in closing it prior to 0. With as much turbine as you have making.it a reverse split like that is pointless imo. I wouldve made the EVC 3 or 5 which wouldve put a little more overlap in it but 13 degrees versus 7 wouldnt have been a big deal.

I agree with the intake lobe duration with you intake. Your motor isnt going.to hit the wall at 6500 like it would if it had a fast on it. It should go 7000 easy. That IVC point is a little late imo with a 3.62 stroke thou. Mightve put it at 48 and shorted the duration a couple degrees which wouldnt change the rpm.capability much if any.

The guys at VS know more about LS cams than i do but the one thing i dont agree with is the EVC point and making.it a reverse split with a stock unported head. If it was something like a trickflow head that flowed more on exhaust i could fathom why it was done.

i think ultimately the car will get some afr 225's.
 
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