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| HiBoost |
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i had a stg 3 crow cam and (with the turbo) the car was making power above 4500rpm? it had the slugishest take off but when it gets to 4500 it just pulled away.... what is the best cam for me? stg 2? or could i retard cam timing so that i start making power just about 2000 when turbo spools up? and how much tooths do i go back?
_________________ 4LTR-JET: 9.1 @150mph!! |
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| xcabbi |
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You advance the came to bring it in earlier and retard to bring it later. Try and get a cam matched to the boost threshold of the turbo or go one step down from that. If your car spools up at 2000rpm then get a cam that has a rev range from 2000 to whatever you want. If there is no cam that kicks in from 2000 then get one that kicks in earlier. That's if you are buying off the shelf cams and can't afford to go for a custom billet cam.
If you got the cash then go for a custom grind. ebs_4l has a pretty lumpy custom grind cam in his car and from what I've heard it defies all logic and kicks in pretty early compared to other turbo cars with big cams which don't move till over 4000rpm. |
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by advancing cam timing will i loose top end power or would i still have the top end power as std cam timing position?
_________________ 4LTR-JET: 9.1 @150mph!! |
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| xcabbi |
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You'd lose a little. Its just that the fun ends a few hundred rpm earlier if that matters. Don't get caught up in numbers on a page unless you have a dyno queen. I'd take a loss of 500rpm up top and have my torque curve come up 500rpm earlier any day of the week compared to having nothing down low and everything up top in one hit.
Just took my brothers VL turbo out for a spin and might I say that on 15psi it is a real pleasure to drive. shh just don't let him know ok 
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| Dansedgli |
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Whack a standard or XR cam in there and see what the difference is before deciding on a new cam. The XR cams are supposed to be pretty good.
What are the specs of your setup? I got a custom grind done by CVE for my EA and the difference was awesome on boost. Boost came on earlier and the cam extended the power range from 4500 to over 5000. The only problem was that my standard computer and microfueler setup couldnt cope with the loss of Vacuum at idle. It fouled plugs often. The cam would be awesome with an aftermarket ECU. Ive since put in a BA motor where stock cams are good for 500rwkw 
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| Smackdown |
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I thought that with boost setups you didn't want to be running much overlap as you are basically sending boost through your engine before it has the chance to combust?
Am I on the money at all here?
_________________ BA Falcon Futura on EGas. Stock as...
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| ef_frmnt |
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air/fuel mixture will spool the turbo up even more so than normal air.. overlap is one thing you want in a turbo cam
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| HiBoost |
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the carank was at top dead centre and the cam gear was flush with the head? so how much degrees do i need to advance it?Power starts at about 4500rpm and all the way to redline ..
_________________ 4LTR-JET: 9.1 @150mph!! |
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| ebs_4l |
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do you have a vernier (adjustable) cam gear??? you do not move the gear by the teeth, you move it slightly via an adjustable gear
the old camshaft VS turbo issue seems to pop up every now and then.. i do have probably the biggest cam of any of the forum members that i know of, i have over 300deg (303exactly) advertised duration..... 242deg at .050 and .576" lift... my cam is so bloody big that i had to grind some material from the underside of my rockers because my lobes were jamming againt the rockers. it does spool up real nice, it makes 16psi at about 3000rpm. it goes into positive pressure from around 2000. i would like to fit a better flowing intercooler, a 3.5in exhaust, and make a manifold from 1.5in steampipe not 1.25. something a bit better flowing oh, also, i have not yet seen where the power curve ends for my cam, as i have not yet revved it hard enough to see the power curve start to die, my limiter is at 5800, and it certainly aint starting to nose over at that point, i suspect peak power would easily be 6500rpm.... damn i need some forged internals.... LOL
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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| HiBoost |
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i have the adjustable vernier cam gear but its not installed in the car yet.... also i went to calder a while ago with the turbo on .... the car had the crappest take off but however when it hit 4500rpm it just pulled away.... costing me slow times but loads of torque up top and power
_________________ 4LTR-JET: 9.1 @150mph!! |
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| ebs_4l |
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has your car been dynoed?????????
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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| HiBoost |
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ebs_4l wrote: has your car been dynoed?????????
yes but cooler pipeing poped off few times and i had fuel issues (chipp needed alteration) and map sensor s**t its self.....
_________________ 4LTR-JET: 9.1 @150mph!! |
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| ebs_4l |
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no point asking here for camshaft advice to fix your problem, you need to get your tune sorted out first buddy...
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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| HiBoost |
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ebs_4l wrote: no point asking here for camshaft advice to fix your problem, you need to get your tune sorted out first buddy...
i have put stock cam back in since the last dyno, fixed piping poping off and its sits on 12.5 PSI without the map sensor s**t it self after a modification to it, also the chip been sent back for more fuel.....so power is ?
_________________ 4LTR-JET: 9.1 @150mph!! |
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| ebs_4l |
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still, unless you have a a/f meter setup in your car (i do) you have 0 idea of what your tune is like, and without aftermarket management, you have 0 idea on how much timing you are running...
without a timing map it is very hard to diagnose a cam timing problem, when we dont dont know, and you cant tell us how much ign timing you have at any given point... this is just 1 of the reasons i am a big campaigner for stand alone management vs an e-series edit/chip what does your fuel system consist of??? what size injectors and pump???
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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