I posted this in the NEWB section since at the time it seemed like some I should know but didn't, but no one has answered so I'm bring it it to the Tech section.

I need an 85mm inlet on an 88mm turbo. Who does this? Does anyone have pics of the reducer or sleeve? Is there a better turbo at this size than the GT47-88 for a 350" motor spinning @7500 rpm? I need answers quick. I need to get this kit started ASAP. Any of our vendors want to build this turbo for me? I need 1200 rwhp from it. Can I just buy a GT47-88 and make a sleeve on a lathe and tack it in place or install it with set-screws?

 

i beleive the tv8101 is a 85mm turbo. some have been mid 5's in the 1/8th

 

there are all kind of things you can do to make more hp than that. if all you are worried about is inlet size a 106/85 or 98/85. which are just the big wheels cut down to spec and then taper out to the full size wheel but inlet size is still small.

 

OK, I think I understand that. This is what the rules state:

Single 76mm T6 Turbocharger (small block) 3100 lbs.
Single 80mm T6 Turbocharger (small block) 3200 lbs.
Single 85mm T6 Turbocharger (small block) 3300 lbs.
Single 88mm T6 Turbocharger with 85mm reducer (small block) 3350 lbs.

That's all. So, you're saying I can run an 85mm inducer that is actually cut from a 106 wheel? How much HP are we talking about here? Ok, I'll take 1 please, LOL. Supporting Vendors, please stand up!

 

by your rules you posted no you cant run a single 106 and an 85mm reducer. you can run an 88mm turbo with a reducer. most of the larger turbos that have reducers have clipped fins on the turbos to fit the reducer and are a completely seperate comp housing all together. id get a upgraded bw unit to 88mm and have somebody do a comp housing for the 85mm at the same time. i dont know of who to ask to do this, but one of our sponsors should be able to accommodate you.

 

If I was building for those rules. I would get the gt-4788 and have the wheel changed out to the new billet wheel and get a cover that was machined to 85mm at the inlet and piss on their korn flakes instead of just letting you run it as a regular 88 mm. The new wheel is worth about 75 hp over the factory wheel. Thats just me though.

 

That sounds hardcore. I like it. Now, about those forum sponsors... Come on guys!

 

There is a big difference in sleeves and clipped wheels and a turbo with a reducer on the front of the cover. Here's what I'd do and it'd be legal based on your rules. I'd take a 98mm turbo, clip the inducer and put a sleeve in through the depth of the inducer bore that gives you an 88 mm minor diameter and the major diameter of a 98mm. Then I'd have a tapered bellmouth reducer made for the front of the cover which tapers the 85mm opening back to 88mm over 6 or 7 inches.

 

that sounds like what they do in NMRA. Who builds them like that?

 

I understand I can't run a 106 with a 85mm reducer. I said 85mm INDUCER cut (clipped wheel?) from a 106 wheel. "trueblue02" was suggesting what Shane explained. I think that is the direction I want to go. Sure sounds expensive, LOL.

 

Before you spend money you might want to call and check rules. I asked and was told the reduced turbos are a no go. Its gotta be a true 88mm i.e gt47,turbonetics. I hate to see you at the track and not allowed to run that class cause of the turbo being illegal.

I know what the rules say and I agree with shane and trueslow but they dont like the turbo cars.

 

These are the rules. If it were as easy buying a GT47-88 and being done with it, I'd have done it by now. 85mm is the inlet size rule. So, even if I just bought a GT47, I'd still need to reduce the inlet size to 85mm.

I agree they hate Turbo cars, that's why I'm going to bust them in the ass with one using THEIR rules. I want to run 5.0's or faster with an "88".

 

Here are some pics of the reducer I had my boss make me for my 101 (down to 88mm). If it were me I would contact someone like Jose @ Forced Inductions or the guys at Supernatural Turbo's. Either of those two places seem to have a good handle on custom turbo's to meet the various rules seen these days.

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I have left Jose a couple messages, hopefully Monday he'll get back with me. I'll also call Supernatural and see what they have to say. Your sleeve looks like what I imagined making on the lathe. If I need to make one after I get my turbo, I'll design it in SolidWorks and make it like Shane suggested with the long tapering bore. Thanks for the pic.

 

some rules dont allow clipped comp wheel turbos. your rules look to be that way, so id double check just in case.

 

His rules say nothing about limiting a clipped wheel. They say 88mm which intimates an 88mm wheel leading edge. So you can clip it all you want as long as your inducer bore is 88mm + the clearance all the way to it's end in the scroll.

 

The Nitrous guys are gonna cry foul, but I'm going to do it anyway. As much as they're going to get away with, I need as much turbo as I can get. If they ban it, then I will have a very nasty 88mm turbo for sale next season.

Shane, I can't thank you enough for your input. It's going to go a long way in my talking to a turbo builder and not sounding like a complete dumbass.

 

yea see i would make sure hes can ue a clipped wheel or he maybe spending a grand or more for a turbo that gets him bands on the first race day.

 

Done correctly, it would be very difficult to tell a clipped 98/88 from a big frame straight 88. Where you get into trouble with rules is when you only clip it 1/4 or 1/2 deep as opposed to clipping it all the way back to the end of the inducer bore. For a while there were no commonly available 85mm wheels and if you wanted that turbo, they were all clipped from an 88. I wouldn't use anything bigger than a 98mm as my base. With the bellmouth tapered reducer on the front of the cover, you will easily make the power you need to make and more. And then you can always pull the reducer for races not under that rule.

 

Ray charles could see the difference between my 98/88 vs the gt4788 or even the y2k88.