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The setup you have if perfect ( except the exhaust, should be 3.5" min tip to tail ), it is just set up and tuned way off the mark

It is 3.5" exhaust, but it is on a 3" cat I think and stepped up to take the 3.5" exhaust

So I guess I need a bigger cat or ?

post-52098-0-76619100-1429936225_thumb.jpg

The dump and cat are the most important part of the exhaust as that is the first port of call for the exhaust gases

Should be 3.5 from the turbo right through

See if you can get that fixed before heading back to CRD

Venom 5" bodied 3.5" cat is best for flow

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The dump and cat are the most important part of the exhaust as that is the first port of call for the exhaust gases

Should be 3.5 from the turbo right through

See if you can get that fixed before heading back to CRD

Venom 5" bodied 3.5" cat is best for flow

Thanks for the info mate ,Paul was saying the 3" cat would cause a problem with the flow.

Here is a pic of the other side of the cat

post-52098-0-82132000-1429939605_thumb.jpg

That cat is really doing you no favours, changing that alone should give you a good gain, this is under the assumption the catylitic convertor is still intact

3.2ltr is alot of motor to flow through a 3" and while it will flow 400rwkw 3.5" will do it easier and with less backpressure, exhaust backpressure hurts turbo performance

That cat is really doing you no favours, changing that alone should give you a good gain, this is under the assumption the catylitic convertor is still intact

3.2ltr is alot of motor to flow through a 3" and while it will flow 400rwkw 3.5" will do it easier and with less backpressure, exhaust backpressure hurts turbo performance

he was talking about the back pressure and said I should have a 3.5" exhaust , I told him he had me put a 3.5" long before the build, then said maybe a 4" would be better?

I do not think they take any notice what they are doing or what they have done at times , I guess when you work on heaps of cars you forget, not hard to have a quick look to see what is holding up the flow and offer an alternative.what if the cat is not intact . If it is not , would it make any difference to change it ?

I will ask about the Venom and do something about it before I take it to Sydney if it is going to help..

I honestly think you need 4inch for the first half, and a 4 inch cat if its "high flow"..

If your keeping it legal then yea a 5" is the way to go

To put it in perspective, Paul has twin 3 inch exhausts on a 2.8

Once again CRD should know better

I honestly think you need 4inch for the first half, and a 4 inch cat if its "high flow"..

If your keeping it legal then yea a 5" is the way to go

To put it in perspective, Paul has twin 3 inch exhausts on a 2.8

Once again CRD should know better

Trying to keep it legal, well as I can, I do not know where I want to stop with the mods :/

Why would 5" be better, do you mean run a complete exhaust system, just spent $2500 on the one I have, haha

4" system with 5" cat.

In the photo it looks like they necked the exhaust to accomodate the small cat.

So in anticipation of the build they tell you to fork out 2600 beer tokens for a 3.5" exhaust and now they tell you a 4" might be better? Alternatively, they built an engine package and tuned it all at your considerable cost, and immediately after tell you the exhaust is too small? Maybe I missed something.

3.5" will be fine for your goal, though a 4" would be better

I have twin 3" into single 4" on my 3.0

Like i said i would change from the turbo to the stepup in 3.5" with a 5" bodied 3.5" cat and be done with it and that will help the turbo response by allowing the gas to get out of the turbo easier

4" system with 5" cat.

In the photo it looks like they necked the exhaust to accomodate the small cat.

So in anticipation of the build they tell you to fork out 2600 beer tokens for a 3.5" exhaust and now they tell you a 4" might be better? Alternatively, they built an engine package and tuned it all at your considerable cost, and immediately after tell you the exhaust is too small? Maybe I missed something.

No Mate , the exhaust was done before I made my mind up to do the build.

But as you can see they did step the exhaust down to fit the cat?

I am not sure if the cat has its internals ??

If I do something with the exhaust I will make sure it is done properly. I will get as much info as I can before anything is done.

4" system with 5" cat.

In the photo it looks like they necked the exhaust to accomodate the small cat.

So in anticipation of the build they tell you to fork out 2600 beer tokens for a 3.5" exhaust and now they tell you a 4" might be better? Alternatively, they built an engine package and tuned it all at your considerable cost, and immediately after tell you the exhaust is too small? Maybe I missed something.

Where do you stop? Exhaust has nothing to do with an engine build. It has everything to do with performance, but if it's not on the list of things to do where does one stop?

Can't expect them to do all the recommendations. Engine build isn't a car build.

Where do you stop? Exhaust has nothing to do with an engine build. It has everything to do with performance, but if it's not on the list of things to do where does one stop?

Can't expect them to do all the recommendations. Engine build isn't a car build.

I thought I was finished with it, haha

Thought the exhaust was OK, I did not just do the motor, did a job on the drive train, C Spec coppermix twin clutch , Quaif front diff, modified the trannie and have a Nismo 2-way LSD on the back and that all works a treat , add the AD08Rs and all good :)

Where do you stop? Exhaust has nothing to do with an engine build. It has everything to do with performance, but if it's not on the list of things to do where does one stop?

Can't expect them to do all the recommendations. Engine build isn't a car build.

Well CRD is a pertormance shop and should know enough to know to atleast recommend enlarging the 3" section to 3.5" while car was getting upgraded

Well CRD is a pertormance shop and should know enough to know to atleast recommend enlarging the 3" section to 3.5" while car was getting upgraded

I think this was another problem, there was no guidance as to what the car needs, to make the bolt ons I chose work better, maybe I would have said NO, but at least put it out there ??

I will ask them what I should do with the exhaust, then I guess I will have to try and sell the old new one :(

Everything seems easier in 20/20 :)

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