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Drivability for high lift cams


Noz
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I'm unsure of what lift mine are but they are 280's and i have 1000cc injectors. The idle when cold goes from trying to stall and the car shudering/rattling to 2500rpm ish, warm it idles as it should smooth at little under 1000rpm. The big thing with my cams (don't think its the turbos fault) is the power climbs and keeps doing so and feels like its still gaining power when the car runs out of revs!..it pulls harder and harder and then the shift light comes on despite still trying to surge forwards.

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I'm unsure of what lift mine are but they are 280's and i have 1000cc injectors. The idle when cold goes from trying to stall and the car shudering/rattling to 2500rpm ish, warm it idles as it should smooth at little under 1000rpm. The big thing with my cams (don't think its the turbos fault) is the power climbs and keeps doing so and feels like its still gaining power when the car runs out of revs!..it pulls harder and harder and then the shift light comes on despite still trying to surge forwards.

 

Yep, your turbo follows the cam profile. You might be better off going down to 269 or 272's, unless you want to build your bottom end for more revs?

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GSC Power-Division's big and nasty cams for the 2JZ-GTE! Not for street use. 1000+ HP applications running anything from Methanol, NO2 or 45+psi. Call for more details. This is a serious cam for serious horsepower.

 

S3 Specs gsc-6030S3

Intake 290 Duration 11.30mm peak lift

 

:cool:

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Mine ticks over very nice with SRD 280 duration 9.9 lift cams.

 

I like the SRD cams myself, they have been proven to work very well, cars with these cams seem to make good power for the turbo size, just look at Jamesy's car and mine, for the turbo size i cant think of any Supras in the uk close to our power.

 

Been thinking about changing to some of the new lighter SRD billet cams with a custom profile at some point, now would have been a good time as my cams are out of the engine at present while Lee changes my car over to L19 exotic studs.

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It's because the lifter buckets are quite a small diameter in the *JZ heads, so a high lift cam runs the peak of the lobe off the side of the bucket, which knackers both the cam lobe and the bucket up. On race engines , given room, you put in bigger diameter buckets to alleviate this problem. There's probably not a lot of meat in the head of a 2JZ to allow much bigger buckets, I have never really weighed one up with this in mind. Really big lift needs a finger follower design set up.

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GSC Power-Division's big and nasty cams for the 2JZ-GTE! Not for street use. 1000+ HP applications running anything from Methanol, NO2 or 45+psi. Call for more details. This is a serious cam for serious horsepower.

 

S3 Specs gsc-6030S3

Intake 290 Duration 11.30mm peak lift

 

:cool:

 

why not for street use? how is this going to affect the drivability.

 

also can someone PLEASE answer my question:

 

same duration with different amounts of lift, how does lift affect performance?

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why not for street use? how is this going to affect the drivability.

 

also can someone PLEASE answer my question:

 

same duration with different amounts of lift, how does lift affect performance?

 

They dont class 1000+bhp as a street car, i do however.

 

The higher the lift = the further the valve rises meaning more air, more air needs more fuel, both combined means more power.

Edited by JamieP (see edit history)
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this will also mean more wear i assume?

 

would anything else need to be upgraded to run say 10.3mm lift than springs and retainers?

 

Most likely.

 

Depends on the power and revs you are going for i guess, If doing it i would and did go the with everything uprated in the valve train, mine has took a lot of abuse this year and Lee reported everything to look as new today so im happy.

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Ok make sense. So if keep the lift low but have a slightly longer duration. Say, 9.9mm lift and 300 duration, this would probably just run as well as 280 duration but choke the chamber more at low RPM, and without a seriously high RPM rev range I wouldnt see any improvement?

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