7a exhaust cam on rs2 setup,yes or no

[mcandmar]

Audi cq? You mean the pic UrS4Boy has posted? that is actually the cylinder head from my CQ20v when i did the head rebuild

[andy10v]

Doug at MRC has dyno plots same engine 7a cams 7a pulled harder coming on boost
Rwd19t has plots with them clocked making great gains

This one?

Look at the plots below on standard chip and turbo that's K24 at 1.1bar. The cylinder head flow figures have been tweaked through valve and seat work resulting in more flow under the lift curve of the cams when opting for 7A exhaust with stock AAN intake.

End result is that the 7A exh mod is more suitable than stock cams for the particular application in question throughout the rev range and especially mid to top.

http://www.s2forum.com/forum/showthread.php?t=10461&highlight=7a+cams

http://www.s2forum.com/forum/showthread.php?t=42953&highlight=7a+cams

Some of the info in those threads seems to imply that a 7a exhaust cam can be useful, with appropriate support.

[Jamo]

The thing with the 7a exhaust alone is you lose low down grunt, ask 4wheeldrifter

[andyg plym]

I know this has been talked about before, and I have done a search. but what I want to hear is from personal exsperiances using the 7a cam with a 3b inlet, as aposed to using both 3b cams,this is with RS2 turbo,EM, injectors,airbox,7a fpr,evo intercooler,3"turbo back exshaust.
What are the pro's and con's of useing the 7a cam,I have one and need to decide whether to use it or not.

i have an rs2 specced aby coupe with 7a cams in and chipped by mrc to 1.9 bar.
having had 5 previous s2's i would say personaly that given a choice i wouldnt bother. im fully aware of turbo lag etc, but the s2 lacks the torque lower down the rev range. i could drive my other stock turbo'd s2's round town all dy in 6th gear and they would pull well.
problem is do you sacrifice low end torque for top end power? i would say go for torque because we all know what speeds the s2 is capable of and nowadays its just too dodgy speeding etc..
just my 2p worth

[UrS4boy]

I don't know if I will be able to explain it correctly, but I'll try.....Sorry if I didn't explain it clear enough or if I said something wrong.
Cheers.

That did NOT answer my question. My question relates to the cam sensor shutter wheel and whether or not you "twist" the exhaust cam 10 deg (like the RS2 exhaust cam) during the installation. As you suggested, you can get a bit more power either down low or up high by advancing or retarding the position of the full valve opening (relative to the piston and crank). With an RS2 exhaust cam, it is rotated 10 degrees to take advantage of this. However, the cam position shutter wheel attached to the RS2 exhaust cam sprocket has the shutter opening adjusted accordingly so the ECU gets the "normal" (like ABY or AAN) cam position info. I installed an RS2 exhaust cam in my AAN but because I only have the AAN exhaust cam sprocket and cam position shutter wheel, I did not rotate the RS2 exhaust cam 10 degrees. I installed it as per normal: O-O marks together. I presume with a 7A cam into an RS2 you would rotate it 10 degrees and reuse the RS2 exhaust cam sprocket and cam position shutter wheel.

Dave F.

[javispa]

That did NOT answer my question. My question relates to the cam sensor shutter wheel and whether or not you "twist" the exhaust cam 10 deg (like the RS2 exhaust cam) during the installation. As you suggested, you can get a bit more power either down low or up high by advancing or retarding the position of the full valve opening (relative to the piston and crank). With an RS2 exhaust cam, it is rotated 10 degrees to take advantage of this. However, the cam position shutter wheel attached to the RS2 exhaust cam sprocket has the shutter opening adjusted accordingly so the ECU gets the "normal" (like ABY or AAN) cam position info. I installed an RS2 exhaust cam in my AAN but because I only have the AAN exhaust cam sprocket and cam position shutter wheel, I did not rotate the RS2 exhaust cam 10 degrees. I installed it as per normal: O-O marks together. I presume with a 7A cam into an RS2 you would rotate it 10 degrees and reuse the RS2 exhaust cam sprocket and cam position shutter wheel.

Dave F.

You are right, I did not answer your question... the thing is that my answer was to 220hp post, but I forgot to quote him. I have now edited and quoted it.
I don't know the answer to your question. The only thing I can tell you is that a friend of mine, with a 3B with RS2 specs mounted the RS2 cam, and I think he installed it with its own wheel. I'll ask him.
From what I have read, the 10 degree difference between the ABY/AAN and RS2 come from the different cam pulley used in the RS2. I don't think that this answers your question, but I am sure that somebody else will.
Cheers.

[prj]

The thing with the 7a exhaust alone is you lose low down grunt, ask 4wheeldrifter

On all cars I've mapped with the 7A exhaust cam I did not feel any difference in spool.
Anyway, at the end of day - go to your tuner and ask. This thread has too much random hearsay by people without experience on the matter.

[220bhp]

This is precisely why I started this thread.There will all ways be for and against,but what I want is to hear from anyone that has fitted a 7a cam into a 3b with a set up
simular to mine,however having said that, I am greatfull for all the comments for or against.

[prj]

This is precisely why I started this thread.There will all ways be for and against,but what I want is to hear from anyone that has fitted a 7a cam into a 3b with a set up
simular to mine,however having said that, I am greatfull for all the comments for or against.

I have mapped a dozen of cars with 7A exhaust cam, while that is not a lot, I told you my opinion... and this is that in case of the RS2 turbo there is no noticeable difference between cars with a similar setup with it fitted and not. 1.5 degrees of timing made a bigger difference than the cam.

[220bhp]

Looks like its my 7a cam up for sale then.PMs please.

[Jamo]

On all cars I've mapped with the 7A exhaust cam I did not feel any difference in spool.
Anyway, at the end of day - go to your tuner and ask. This thread has too much random hearsay by people without experience on the matter.

Re-read my post, I said grunt aka torque not spool

[prj]

Re-read my post, I said grunt aka torque not spool

Spool and torque are connected...
Anyway, what I mean is - I really did not notice it driving any worse off boost with the 7A cam. Neither did I notice it driving any better on boost really...
With larger turbos, the difference is more pronounced, but with the RS2 unit, I don't think so (read: it was not enough for me to notice).

To the OP: If you have the cam already, no point selling it.
Just fit it, since you will get a bigger turbo someday anyway.