turbo and cam sizing
02-23-2012, 12:57 PM
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turbo and cam sizing
Well motor is coming out as we speak today to diagnose the issue (seems to be the headgasket has let go) and when it goes back together im changing it up a little bit since my 2871's appear to be maxing out (or could possibly be the cams not flowing enough as to which that is im not sure)
Im looking to do cams and all that accompany them, having a hard time deciding on sizing though. i think a 264 in and out would be adequate but i dont want to get those in and still not flow enough on the top end, but im afraid a 272 will take too much off the bottom.
And as far as turbo sizing im limited by the small t25 gtm manifolds.
so im limited to a few options:
this in a .86 AR
http://www.atpturbo.com/mm5/merchant...Category_Code=
or this with a gtx wheel but a smaller .72 AR
http://www.atpturbo.com/mm5/merchant...Category_Code=
For refference currently have vq35hr (now 4.07L BC stroker)
8.59:1 cp pistons
ported and polished heads
cjm twin hangar and full return
currently dw850cc injectors (thinking of swapping to id1000's if i change turbos)
thoughts/advice on what you would do?
Im looking to do cams and all that accompany them, having a hard time deciding on sizing though. i think a 264 in and out would be adequate but i dont want to get those in and still not flow enough on the top end, but im afraid a 272 will take too much off the bottom.
And as far as turbo sizing im limited by the small t25 gtm manifolds.
so im limited to a few options:
this in a .86 AR
http://www.atpturbo.com/mm5/merchant...Category_Code=
or this with a gtx wheel but a smaller .72 AR
http://www.atpturbo.com/mm5/merchant...Category_Code=
For refference currently have vq35hr (now 4.07L BC stroker)
8.59:1 cp pistons
ported and polished heads
cjm twin hangar and full return
currently dw850cc injectors (thinking of swapping to id1000's if i change turbos)
thoughts/advice on what you would do?
Last edited by ace32x; 02-23-2012 at 12:58 PM.
02-23-2012, 01:33 PM
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also was talking with my fabricator at work and he was saying he could cut the t25 flange off and either weld or braise on a t3 flange on the gtm manifold to fix the issue
02-23-2012, 01:59 PM
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I'm running the 262 cams from JWT with no issue with my 3071R with billet wheel
You don't want your power to go too high on the RPM range unless you want to always be high in the RPM range to get power
You don't want your power to go too high on the RPM range unless you want to always be high in the RPM range to get power
Last edited by Glex25; 02-23-2012 at 05:48 PM.
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02-23-2012, 05:46 PM
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hey sorry for stepping in , but I am also looking for cams and cant decide if I should do 262 or 272. I'm single 6765 with a rev up no port or polish, stock valves , upgraded springs.
If someone could recommend which cams I should get, Since I'm already moving the power to the right with single turbo would 262 give me more mid range and lower top end? or should I just go 272 since I wont make much power in mid range anyway ???
If someone could recommend which cams I should get, Since I'm already moving the power to the right with single turbo would 262 give me more mid range and lower top end? or should I just go 272 since I wont make much power in mid range anyway ???
02-23-2012, 05:49 PM
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I was mistaken my cams are 262 JWT S7R and I'm running twins
I have a dyno graph with a slipping clutch
Next month I'm going for a new tune and will have a better graph for you
but if you with too aggressive a cam your power range might be too short and high in the RPM range
I have a dyno graph with a slipping clutch
Next month I'm going for a new tune and will have a better graph for you
but if you with too aggressive a cam your power range might be too short and high in the RPM range
Last edited by Glex25; 02-23-2012 at 05:52 PM.
02-23-2012, 05:57 PM
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I was mistaken my cams are 262 JWT S7R and I'm running twins
I have a dyno graph with a slipping clutch
Next month I'm going for a new tune and will have a better graph for you
but if you with too aggressive a cam your power range might be too short and high in the RPM range
I have a dyno graph with a slipping clutch
Next month I'm going for a new tune and will have a better graph for you
but if you with too aggressive a cam your power range might be too short and high in the RPM range
stage 1
256 intake duration/10.50mm lift, 264 exhaust duration/10.5mm lift.
stage 2
272 intake duration/11.0mm lift, 272 exhaust duration, 11.0mm lift.
or one of the Tomei cams ...
02-23-2012, 07:00 PM
#12
im still waiting on them to show up but i went with something alot of the domestics do and am running a reverse pattern vs the square pattern most of the vq people are running. stage 1 NA kelford intakes and stage 2 FI kelford exhuast, it should give me the breathing on the exhuast side to still rev it out but leftshift the powerband some because of the NA style intake cams. i just will have to run more boost to hit the same power as others with bigger intake cams, which is fine since you really cant take full advantage of the billet precision wheels till 28+ psi thats where they really start flowing more then the cast wheels according to my talks with precision.
i will admit i have no idea how this style setup will work on a engine with variable valve timing though.
i will admit i have no idea how this style setup will work on a engine with variable valve timing though.
02-23-2012, 07:07 PM
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im still waiting on them to show up but i went with something alot of the domestics do and am running a reverse pattern vs the square pattern most of the vq people are running. stage 1 NA kelford intakes and stage 2 FI kelford exhuast, it should give me the breathing on the exhuast side to still rev it out but leftshift the powerband some because of the NA style intake cams. i just will have to run more boost to hit the same power as others with bigger intake cams, which is fine since you really cant take full advantage of the billet precision wheels till 28+ psi thats where they really start flowing more then the cast wheels according to my talks with precision.
i will admit i have no idea how this style setup will work on a engine with variable valve timing though.
i will admit i have no idea how this style setup will work on a engine with variable valve timing though.
02-24-2012, 05:52 AM
#18
I'm running a very modified JWT 700 kit, had some issues with my turbos dieing on me so I had a buddy make me some Frankensein's that are a little different the the GT2871's the kit came with. The plan is to run about 22-25 psi and shoot for 550-575 at the wheels, but I dont have any head work other than cams and springs right now. I've got another set of heads that I'm going to build this winter though.
02-24-2012, 07:16 AM
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I'm running a very modified JWT 700 kit, had some issues with my turbos dieing on me so I had a buddy make me some Frankensein's that are a little different the the GT2871's the kit came with. The plan is to run about 22-25 psi and shoot for 550-575 at the wheels, but I dont have any head work other than cams and springs right now. I've got another set of heads that I'm going to build this winter though.