mx5cartalk.com

Hi guys,

I have an NA6 with a garratt M24 ar80 turbo. It doesnt kick in until 4500 rpm, is this just a tuning issue and can I get it tuned to kick in earlier?

Im running 7psi (170 rwhp)

Thanks Nicky

Its just an S13 turbo.

Im guessing you have a small dump pipe or exhaust. Amirite?

Dann

Sorry Dann, not sure, i think the exhaust has been upgraded as the previous owner did a bit of rallying in it. I have a pod filter and extractors. Sorry I cant give you anymore info

If you don't know the spec of your setup, how can people help?

As I am not mechanically minded, I was unaware of the amount of info you would need, sorry.

Its all good.

Basically a common issue with the mx5 world for some reason, is exhausts that are far too small.

A big exhaust allows the exhaust side of the turbo to breath much better, spinning easier, and that of course spins the compressor side easier. And then viola, lag be gone.

JOJO82's car has a little T25 of an S13 too, and starts boosting at 2000rpm, its not a fancy manifold but it does have a full 3" straight through exhaust, that would be the first thing, check the exhaust diameter.

Dann

Well done Dann.
My ute muscles with a smoothed turbo and a better exhaust. 'The pipes, the pipes'.
Greg.

I think it's an AVO kit on Nicky's car.

Did the 1.6 AVO kit have that restrictive notch in the dump pipe to clear the firewall?

Yes, it sucks.

Im building Patrick Bramston a whole new setup fixing that issue and a few other things very soon, His car doesnt come on till 4000 odd either.

Dann

Just have to drive it quicker Nicky and keep the revs up

Yes it is an AVO kit on mine. Thanks for your help guys, I will do some more investigating, it would be great to get it to kick in at 2000rpm

sticky nicky wrote:As I am not mechanically minded, I was unaware of the amount of info you would need, sorry.

Don't be sorry nicky, you gave as much info as you knew, and asked a straight question, theres nothing wrong with that, and then someone will ask you a question, and in the end you get the answer you asked for.
Thats how forums work, some people just expect you to be a mechanic

Cheers
Dale

Thanks Dale, I plan to check out my exhaust today and see what Ive got.

Has nothing to do with the dump pipe at the boost, it's your wastegate actuator, get a Turbosmart t piece it will fix it instantly, had the same problem recently with the same turbo,
Instantly picked up 30 kw@ the wheels with the boost controller.
Steve.

But the question is how to make power earlier, not how to make more power.