[Scrawny]

How will they go with under 6psi boost? Thinking light aircraft tug with short bursts of 10 mins at around 150hp. Doable?

[ozzycouch]

PM zook_ute, he was running a turbo for a while, can't remember if it was modified though.
I can't see a problem with running a bit of boost, my old mini with stock guts ran about 7 psi, and it only had three crank bearings. Lol

[greenzook89]

I've got no firsthand experience, but the swift people seem to have very few issues running the M15/16/18 with a turbo and 8psi or less. When I was looking at boosting Mrs Greenzook's Swift, if the boost was kept low internals weren't really an issue.

There is also a bloke in brissy with a M13A turbo Jimny, running 5psi and no management changes and it hasn't become a grenade..... yet....

[Scrawny]

So light boost won't be an issue then?

[greenzook89]

If it was me, I'd boost a M18, quick look tells me the M18 has a 9.6:1 compression whereas the M16 has around 11:1

A good friend of mine runs a twin turbo VQ35 which from factory has around 10.3:1 Compression, has been feeding it 8 psi for the last 2 years with a great tune (310rwkw) and no issues.

Adding boost to a high compression motor comes down to the tune IMO.

[royce]

Yeah they go ok

I'd probably go with an M18 just to get a bit more size and ease of purchase