7A Exhaust Cam

[Jamo]

appearently i read in a german forum that Peter from PKmotorsport that his view is that matching the 7A cam with an ADU inlet it wont give anything obvious because of the overlap.Dope!!!! so me getting the 7A cams was useless??? Will it be any better if both of them are used??

Running both 7A cams would give you stronger pull from when on boost and up to redline at the cost of adding about 200-300 rpm lag.

Glad to see a tuner has backed up the theory with results

[A80Avant]

I have emailed Peter myself but havent got an answer yet.I just found that from another person mentioning it.If i get a definitive answer then ill post it as well.

Jamo,do you reckon then that it is best to see what the result will be to use both cams and remap?I mean i do have deliberatelly a little lag on although the 3071 can come in sooner,so my bet is that with a remap i can keep the same lag as now.Will it be any better than the RS2 cams though?

I have been trying to get an answer from MRC as well,but no luck..

[Jamo]

Unfortunately there's only a few real world results out there but all with various specs.

I know of a few forum members who ran the 7A and are now reverting back to stock cams. The best option was the one Prosty did, he had the 7A cams reprofiled which knock 1000 rpm of his lag with his turbo.

Personally i'd go the opposite and look for a standard AAN / ABY exhaust cam and give it a test.

[A80Avant]

i have talked to prosty and he said that he eventually didnt loose all that 1000rpm as he was promiced.His view was to go for a set of cams from new at the end of the day.Yes i know Peter offered me a set of cams which run from 3500-7800rpm adjustable but i would also need to change the springs for 760euro.I got the 7A cams much less than that...

i would like to test them and decide,only i dont know the costs of that.I would need to have the car on a dyno,do a pull with the RS2 cams i have now,change the cams to 7A,remap and do a pull again...not cheap i reckon!

[A80Avant]

Talking to Javad,he recons that the use of both 7A cams on a GT3071R setup is better than the ADU cams and they generally use them for that purpose.Both of them that is..

[Rusty]

Basically you can use whatever cams you want but you have to accept that with both 7A cams the lower end performance will be lesser. The ADU cams are a good compromise and the ABY inlet/7A exhaust is a proven setup for cars running 400bhp or so by Doug. It's all down to what you want to achieve really...

[A80Avant]

to get things straight in my mind,when you say that low end performance,what rpm range do you mean?

Is it from 2500-4000rpm? cause the performance there is already low due to lag.SO basically the ADU cams,could have been working with a smaller turbo (or the RS2 turbo for that matter) but since that is now bigger(GT3071R) then what is the point?I know the 3071R is a small turbo to be honest and if it wasnt for all that surging it could have been made to work as it did initially with my first map which was coming on from 3300-3500rpm,but now since im already closer to the 4000rpm range for full boost,does it mean that by using both 7A cams the 2500-3500 range will be even lower in power?Does it mean that the car will not be as lively? or is it something that can be overcomed by mapping?And to what extent?

Ross made full boost with his 3071R turbo @ 3500-3600rpm more or less by using the 3b inlet and 7A exhaust cam.How big of a difference will it be to go for both 7A cams then?(dont want to spend more money getting 3b or aan cams now...)

[Rusty]

The RS2 inlet cam is the same as the rest, it's simply the exhaust that's different and the RS2 cam pulley.

[A80Avant]

so the cam pulley makes the difference in overlapping then?

[Rusty]

Nope. It adjusts both cams, there isn't any overlap from what I understand

[A80Avant]

i meant if someoone would use only the exhaust 7A cam with an ADU sproket and ADU inlet.
would there be any overalap if there were both 7A cams there with ADU sproket?

[A80Avant]

Let me put it in another way.Since it all boils down to what you want from the car to perform:

If you had a turbo that spools after 3800-4000rpm would you go for ADU cams or 7A cams ?

[Rusty]

I'd personally try 7AexADUinlet / both 7As or perhaps some CatCams if I was feeling flush.

[A80Avant]

I do want to give the 7A cams a try,but with the according remap done.Thing is that this should be done properly on a dyno with a before and after run to spot the differences and decide what needs to be done....

[Bram]

I asked also these questions to Javad and he recommended to use both 7A cams for the GT3071R turbo as he has done a few tuningsessions with good results he said. However he advised to retart the 7A cams for less lag in the lower revvs and higher outpu top-end.

I also asked the question to Marc Swanson and he recommended to use the ABY inlet and 7A outlet for best results.

So I guess the main question, reading all these speculations and answers; What is meant by the best performance?
High top-end power, good powerband from low revvs to redline, same spoolup compared to stock cams, etc.

The more I think about it I think I will stick with my ADU cams and camwheel.......

But I feel tempted to try the ABY inlet and 7A outlet one time......