Smith-02

pablo83

Feel better now?

Pdub383426

I had a gt28 on my 686cc Yamaha, and now have a gt20. Still a little too small, will be looking into a gt22 in the near future. Made 70hp at 8psi with the gt28

pablo83

Would you mind giving me more specifics on your install? What model bike was it? Do you know what HP it made before the turbo? Was your turbo oil, or air/oil cooled? How is the lag? Thanks.

Pdub383426

It is a Raptor 700. It made 46.5hp before, that's with K and N, stock pipe without spark arrestor. Turbo was oil cooled. The lag with the GT28 was pretty nasty, I went to the gt20 and it hits very soon in the RPM range. The gt28 probably would have worked better, but I used a stock pipe and mounted the turbo up under the subframe, so it was a direct shot to my throttlebody. I've seen other GT28's used on Raptors, and work real well when the turbo is right after the exhaust ports, I just didn't have the tools to mount mine there with the two exhaust ports coming out at different angles.

Might want to look into making yours EFI if it's the Honda 650, the new Trx700xx comes with EFI you might be able to adapt, it was originally build off the Honda 650 (late model)

pablo83

Thanks for the info. It sounds like my project will be very similar to yours. Do you know what production years of the raptor come with EFI?

Pdub383426

06-09 All have EFI, that can be found on the internet. The throttlebody's are 45mm stock, and can be bore to 48mm, more than enough to feed a 650cc motor. And there are aftermarket Throttle body's available up to 54mm right now, but they're pricey as ----. Your best bet is to fab up a raptor one, or a new Trx700xx Throttle body and fuel pump. The carbs on offroad bikes seem to have alot of trouble, with debri and all. The self correcting closed loop systems make turbo's for us cake