Trying to reduce EGTs - Downpipe diameter?

[Vitwagen]

My EGTs are too high for my fuelling (IMO), and I'd like to get them down.

It's a AAZ with a garrett T2, 10 PSI boost, a tiny bit of extra fuel and no gov mod. It's also in a Suzuki Vitara (sidekick or tracker in US).

So the downpipe I have is about 1.75" (less on the bends). If I get that up to 2.25" will I see the reduction I want? The rest of the exhaust is 2.25" with just a flowmaster muffler.

I can see EGTs of over 600*c with no smoke AT ALL. timing is at .95 and the engine is otherwise healthy.

Over to you guys 

[theman53]

600c is just around 1100F...I would love to have those numbers. I see 1500F if I stay on mine *which I don't more than maybe 7 times in the engines life* which would be somewhere around 800c. It is accepted that 1200F is a good safe range which you should have no problems.

I bigger exhaust should do no harm to your EGT situation. It should help, but it isn't for sure. It will flow more so if you have a restriction then it will help. If the pipe you have now flows all you need it probably won't change. 1.75" is small probably around 1.5" at the bends, so yeah you should see a drop in EGT and probably even quicker spool.

[vanagonturbo]

Bigger downpipe= lower EGTS, more boost, faster spool. Go as big as you can fit.

[theman53]

BTW I did use 3" all the way from the turbo back on my setup...no such thing as under kill

[vanagonturbo]

BTW I did use 3" all the way from the turbo back on my setup...no such thing as under kill

There is such thing as rattles though