Disc ratio? The hell are you talking about? You talking about the air fuel ratio I'd assume, just bring it to a shop with a dyno and have them tune it, they'll know the proper AF ratio to tune for. I'm assuming you'll just be using an S-AFC to tune?

 

you'd be a lot better off with something as simple as an SAFC over a FMU... an FMU might get you to the point of your engine being safe, but it'll never be a perfect tune with one. you'll go from being rich out of boost to possibly being ideal under maximum boost, but anywhere outside of your short ideal stretch you'll be lean or rich.

 

I really hope by FMU you didn't just mean a fuel pressure regulator.

 

With the FMU it would run normal under boost its just i dont know which ratio i should use lik a 12:1 ratio for example. So with every one pound of boost i would get that much more gas so if i had the right raito i wouldnt need SFAC i would just need a AF guage to make sure that it is right. Also not its a Fuel Management Unit. I live in knida a small town in Iowa their are no performace shops around. The only dyno we have is at a college that isnt open to the public and at a disel shop which u can use but not to tune.

 

Yeah I know what FMU stands for lol. An S-AFC is technically an FMU. Most shops tune for about 12.5:1. If you have a wideband and a long stretch of road you'd be fine tuning with an SAFC.

 

i was told that DSM turbos have special plate ..... but iono , just what i herd from the grape vine

 

different flange designs, yes

 

wat do u mean a special plate.

 

How about getting a wideband and putting it in your car so that YOU can tune it?

 

Special plate? No. lol

 

yeah i knew that my buddy will make me a manifold since he works at a welding shop. I do want to get a wideband but i dont get much money from my job so im kinda doing it cheap but no ghetto riging it. So i still want to go with the FMU.

 

hmm, I know with stock 270cc injectors, a 10:1 ratio would suffice. How big are dsm's? What you can do is start with a rich ratio like a 12:1 and use a valve (aka boost controller) in the vacuum line connected to the FMU to change the ratio. Yea, it's pretty ghetto, but I don't think you care because you're already using a FMU, haha.

 

let me kno if u need any single slammer parts i have a complete engine i'm parting out

 

Flanges change from turbo to turbo though, thats a given.