turbo M7

[MrMagoo]

Hey guys I'm thinking hard about a turbo for my m7, its a light and nice handling sled so i dont want to trade for a m8. How happy are you guys with the turbo'd m7?? I understand the electrical complications with the 700 motor but from what i've been told that 10lbs of boost is about the max or else you cant get enough fuel??? Have you guys had any issues like that while running more boost??

thanks

 

[DWHalverson]

I consistantly run mine 12-14psi and have run it up to 18psi before. This is with auxillary injectors though. They are fun and I think you will be happy. I think the M-8 only has a little better bottom end over the 7.

 

[altai1970]

I am in the same boat, looking to turbo my M7 too..... Does any motor work need to be done? What kits are preferred?

Any input from the M7 turbo guys is appreciated...

 

[bigbull]

If I was to set up some more M7 turbos I would do some things different. The electrical issues were frustrating and not worth running the dual injectors IMO. I actually had great power with two injectors at 8-10 pounds with the stock fuel pump.

I would purposely build a 2 injector setup with a garret turbo and run some 50/50 fuel up to 8 pounds and then run full race fuel up to 10 pounds. I would also try to get a consistent cold air flow into the intake WITHOUT an innercooler that arguement is not worth discussing here), I.E. pulling air from outside the hood and having a short and well built charge tube to the airbox. I would have a blowoff valve. I can't answer for Pure Logic, but Attitude will build you a fuel controller for this application. If I was planning on running about 8 pounds of boost most of the time (best for not pushing the duty cycle of just two injectors) I would make sure I was running about 28:1 to 32:1 (factory Cat oil settings on the oil control arm) and leave the oil injection in place. 10 pounds consistently on long climbs, well, the oil would get kinda thin and motor and egt temps would be high. It would rob life from the crank and bearings for sure. So would probably premix at 44:1 and pack an extra set of stock injectors in my pack.


These are my opinions based on the facts and experience of myself. So I am not saying other peoples ways are wrong. I just happen to think for that sled in particular, this is the best way to go, all things factored in.
BB

 

[bigbull]

And regarding the motor, nowadays most M7 sleds have some serious miles on the motor and crank. Put everything back to stock, tear the top end down and replace pistons, rings, roller bearings with OEM product replacements and inspect the cylinders for wear and tolerance. If its over 3000 miles, new crank and bearings and water/oil pump seals etc.

There are some DD gearing changes that can help with some clutching differences between the M8 and the M7, but good clutching like OVS, or Twisted, or Boost Addict's will make most engagement issues and belt life improve good enough.
BB

 

[m7]

I rode one two weeks ago. Man the thing pulls like a jet going down the run way to take off. You can pm luckylyle or mtsthelens on here they both run turbo m7s.

 

[altai1970]

Bigbull- thanks for the great and detailed info....were you building your own kits, or using someone elses? How was the reliability in the M7's that you were around? At 8 pounds, is straight AV gas ok?

thanks again,

 

[mtn_extreme]

I would have to give the flip side to BB's assesment. I run a 2005 M7 with an M8 bigbore kit on it. I put a race gas Twisted Turbo on it at the beginning of this year with the sled having 4000 miles on the bottom end. I have run 110 octane gas at 11-12 lbs boost all year with internal air intake (mesh hood) , no intercooler, and I prefer to premix, you loose the weight of the oil tank and on pulls where you are boosting more fuel in with the turbo you need to have more oil to compensate. The oil pump on the injection system doesn't add any more where if it is premixed in the fuel already it is even. I run 40:1 ratio of AC apv oil. I run duel injectors and have not had any problems with electrical problems and the twisted kits replace the stock fuel pump with high flow pumps. (I don't run a headlight though).