N/A Cams VS TT Cams. Benefits from mixing?

[3000gttom]

good info... thx

[3000gttom]

i guess they arent all the same profile then... really doesnt make sense to run more overlap on the turbo car though

o well i guess it was the same engineers that decided to make a turbo car for low end torque lol and get waxed by supras

[J. Fast]

i guess they arent all the same profile then... really doesnt make sense to run more overlap on the turbo car though

o well i guess it was the same engineers that decided to make a turbo car for low end torque lol and get waxed by supras

It doesnt matter if they have more overlap. What matters is how high they lift proportionate to another. Is one open full bore while the other is cracked a smidgen? If that's the case they're still in overlap becase they're both open but the reversion rate is less. You have to take into account the position of all the moving parts in the combustion chamber vs. time vs rpm.

I'm surprised you challenged Mc.. Hez a Mastar Tek ...

[3000gttom]

yea hes a nice guy... technically we were both wrong in parts lol

overlap is actually quite important and it only happens with both of them just barely cracked because the piston is at top dead center at that point... for turbo cars adding overlap generally makes turbos spool later and you can gain some top end power but you have to watch out because EGT's will go up... i guess they are at a good setting for the tiny 9b's though

[RealMcCoy]

yea hes a nice guy... technically we were both wrong in parts lol

overlap is actually quite important and it only happens with both of them just barely cracked because the piston is at top dead center at that point... for turbo cars adding overlap generally makes turbos spool later and you can gain some top end power but you have to watch out because EGT's will go up... i guess they are at a good setting for the tiny 9b's though

Show me where I was wrong on anything I posted....?

As with any stock cam, it was made to compromise between performance, drivabilility and emissions... You can make more power by decreasing the lobe centers and retarding the assembly as a whole. (primarily done by retarding the exhaust cam) Obviously the real solution would be to buy much bigger cams, but particularly in this platform, we're quite accustomed to making the most of what we have...

Narrowing the lobe centers and retarding just moves the torque curve to the north... Something that has been proven countless times to benefit our cars over the years, regardless of what turbos are used.

[Blackmount]

moves the band north eh?

[RealMcCoy]

moves the band north eh?

Unless you're in Australia, that means up...

[3000gttom]

TT and N/A cams are the same profile.... TT exhaust cams are retarded 2 degrees to INCREASE overlap.

look at the profiles again... the intakes are the same the. on exhaust the TT opens 2 degrees sooner and closes 2 degrees later so they arent the same profile. TT is 247. NA is 243

edit: i dont know if the intake cam lobe centers would line up but its possible that putting intake cams on the exhaust would give TT guys a 4 degree bigger cam and 2 more degrees of over lap and n/a guys could get an 8 degree bigger cam and 4 more degrees of overlap

[RealMcCoy]

look at the profiles again... the intakes are the same the. on exhaust the TT opens 2 degrees sooner and closes 2 degrees later so they arent the same profile

I think you need to familiarize yourself more with the meaning "after" and "before" TDC.... Both events happen 2 degrees later.

[J. Fast]

look at the profiles again... the intakes are the same the. on exhaust the TT opens 2 degrees sooner and closes 2 degrees later so they arent the same profile. TT is 247. NA is 243

edit: i dont know if the intake cam lobe centers would line up but its possible that putting intake cams on the exhaust would give TT guys a 4 degree bigger cam and 2 more degrees of over lap and n/a guys could get an 8 degree bigger cam and 4 more degrees of overlap

you're going in the wrong direction. you want the exhaust hole as small as possible when you have a ton of back pressure from tiny turbo.

do you understand the cam timing information McCoy posted?