7A exhaust Cam

[karlblues2]

OK. Stupid question time....
What is the 7A exhaust cam, why is it better than the ABY one, and how easy is it to fit? Also is it an essential upgrade for my ABY if replacing the turbo to an RS2 stage 3, RS2 injectors and RS2 e/m?
Cheers guys
Karl

[martinjs]

It has higher lift than the stock s2 cam, so opens the valve for longer, i think its pretty much the same as the RS2 ex cam, but a lot cheaper,
It helps with top end power, i have one fitted, along with RS2 bits, but fitted everything at the same time so didnt notice what differenct a cam alone will make.
You can fit the inlet cam from the 7a also.

martin

[karlblues2]

It has higher lift than the stock s2 cam, so opens the valve for longer, i think its pretty much the same as the RS2 ex cam, but a lot cheaper,
It helps with top end power, i have one fitted, along with RS2 bits, but fitted everything at the same time so didnt notice what differenct a cam alone will make.
You can fit the inlet cam from the 7a also.

martin

Thanks for the reply Martin....Anyone know how much they cost????
Can we get them through VAGPARTS??
Cheers

[4WheelDrifter]

7A valve timing at 0.1mm lift.

Exhaust opens 42° BBDC
Exhaust closes 3° BTDC
Inlet opens 6° BTDC
Inlet closes 38° ABDC

HTH

[Jamo]

Do we have the spec of the RS2 cam to compare?

[4WheelDrifter]

RS2 valve timing at 0.1mm lift.

Exhaust opens 24° BBDC
Exhaust closes 1° ATDC
Inlet opens 13° BTDC
Inlet closes 35° ABDC

I think that's right.

[Jay]

RS2 valve timing at 0.1mm lift.

Exhaust opens 24° BBDC
Exhaust closes 1° ATDC
Inlet opens 13° BTDC
Inlet closes 35° ABDC

I think that's right.

Compare the to over laps between the cams- not good on a turbo car you loose loads of torque, unless you are going for a all out comp car you will destory the driveabilty and fuel econ.

Jay

[4WheelDrifter]

I don't think there is any overlap on any of these cams.
Is that right?

[Jay]

I don't think there is any overlap on any of these cams.
Is that right?

There is always overlap on all engines, single or twin cam, its when both valve are open at the same time between the exhaust stroke and the inlet stoke.

Also NA cams have to much duration this to to promote scavenging of the cyl and is more important on NA than turbos.

Jay

[4WheelDrifter]

Don't worry. I had a moment then.
Got my ATDC mixed with my BTDC!
D!ckhead!

[Greg_S]

been thru this one before in some dtail i think and it was worked out there wasnt overlap with them

[karlblues2]

Don't worry. I had a moment then.
Got my ATDC mixed with my BTDC!
D!ckhead!

OK! So for Mr Thicky here, can you repeat the correct ones please

[4WheelDrifter]

Sorry. I was Mr Thicky. AFAIK the timing figures are ok. I just read them wrong thinking about overlap.
Should get some glasses really!

[Greg_S]

http://www.s2forum.com/forum/showthread.php?t=1649&highlight=cam

http://www.s2forum.com/forum/showthread.php?t=1477&highlight=cam

some reading for you

Greg

[4WheelDrifter]

Actually, the figures i have for the 3B cams show the exhaust closes at 9° BTDC and the inlet opens at 3° BTDC. Can anyone confirm this? 6° with both sets of valves shut. That would be a small compression just before the intake stroke.