rx7tt95

Despite the quite pleasant 80 degree temperatures in Southwest Florida today it was Christmas and Santa paid a visit to drop off a rather heavy turbo into my possession. Formerly a GT4082 with the 82mm exducer wheel, little bob was sent packing to the North Pole where he went through a regiment of training to become big bob, aka Mr. Magic (Sean will get the joke) sprouting the rare 88mm 54-trim compressor section. This turbo doesn't exist unless you modify a 4082 yourself or possibly get one through Sean at A-Spec. It's a fully divided .94 hot side using the GT turbine (what others call the GTQ?), all GT spec front to back, plain bearing. It's possible to get a T04 hot side with this turbo but it's using the heavier, more restrictive old-school turbines.

Here are a few images. I don't have any tools to get the compressor cover off so no shots of the full compressor until later tonight. I'm hoping for big things with the new CLR Motorsports-built Cosmo 13B engine and the new turbo. I'm thinking 20psi daily driven on pump gas, no alcohol or water injection. Intrigued?

rx7tt95

A few more pics. V-band discharge on the compressor was ground down. It's now 2.5" diameter. So one would need a 2.5" to 2.75" silicone coupler. The turbine discharge was shortened and fitted with a 3" V-band courtesey of lots of hard work by N-Tech Engineering. The rebuild/mod to the compressor was done by Majestic Turbo. They could not get their hands on a 4088 wheel, but Seat at A-spec had one in stock. In the end, it'd be easier to just buy a GT40R with the .96(?) hot side but at the time, I didn't have that option as none were available. Regardless of the time/cost (hey, it's only money!) this turbo should perform rather well.

concept-R

Can't wait to see this on...along with impressions.

modrx7

iTrader: (1)

Looking Good that compressor looks exactly like the one I am selling now... if you look closely... see sig for pics. It WILL perform very well for you Glad to see its back in your possession.

Edan

modrx7

iTrader: (1)

SpoolinRX

iTrader: (6)

Nice, that thing is massive

rx7tt95

It's not too big actually...a lot smaller than a GReddy T78 in physical outside dimensions. About the same size as a T04S but with a slightly bigger compressor and exhaust wheel.

Poweraxel

cool glad you got that turbo together... have fun!


Steve

pianoprodigy

Very. You must like to build engines. j/k Good luck the build up!

Dwood432

huh, it looks familiar.

rx7tt95

Well Piano, it comes down to tuning, a great engine builder (Carlos Lopez) and a few internal tricks which allow higher boost pressures on pump gas. It isn't rocket science but most don't seem to discuss it or even consider it on the single turbo forum. There's a member of this board who runs a very similar setup with alcohol injection on 93 octane who's putting down 490's at the rear wheel with a CLR-built engine. His dyno sheet is posted. Not really shooting for 490 on pump and I don't plan on running alcohol injection. I'll be very disappointed if I do not hit 450 on pump.

Dwood, that'd be the larger hot side, correct? It'll be interesting to see how it spools. When do you think you'll have everything together and tuned?

pianoprodigy

Yeah, I probably sounded like an *** there, but, as you know, the forum consensus is not in favor of running that much boost on pump gas. By a few "internal tricks" I would think you mean lowering compression since that is really the only way to lower the chance of detonation (that I know of anyways). Is there a reason that you're against alcohol injection? It seems to me that there are no drawbacks from running it other than the fact that if you tune for it, you had better not run out.

Dwood432

Nope, I have the .94 hot side too. Garret originally only offered a 1.34 hot side. Sean and I talked, and decided that it was better for what I wanted to do to go with the .94. So he had Garret make the .94 hot side for me.

I *hope* to have everything together and running by early April.

rx7tt95

Piano, no, didn't sound like an *** :-) I'm well aware of the general forum consensus and most times those assumptions are wrong. Waaaay too much disinformation! Yes, lowering compression is one trick. But by just dropping in low comp S4 rotors, one increases the reciprocating weight fairly dramatically. CLR addresses this by having the rotors ligtened to 93-spec and dynamically balanced. I'll try and get Carlos to send me a pic of one of their rotors. They're pretty neat and for lack of a better term, they have scallops on the combustion faces allowing the intake "stroke" to occur that much sooner. Combined with some timing/tuning tricks, 3mm mm seals, it works wonders on a rotary's reliability.


Out of curiosity, how much did your 4088 with the custom hot side run? I spent enough to purchase a 40R by the time I got done with the initial turbo purchase and upgrade! I should have mine together within a week or two.

rob20rx7

iTrader: (1)

i dont think carlos is going to allow pics of that to be posted. that work that he does is a science and a specialty which he holds close so no one else can R&D it. (Rip off and Duplicate)

i can tell you that it does work. i dont have the scallops and lightning of the rotors, but do have low compression Turbo II rotors. and they do help with higher boost applications. I do plan to do the scallops and balancing sometime in October..

Laters
Rob

rob20rx7

iTrader: (1)

By the way... Forgot to mention. THAT TURBO LOOKS PIMP!!!!!

rx7tt95

LOL rob...actually he said the rotor pics were ok to share! Showed me a few other things I absolutely cannot share but the rotors are ok. Even if someone did see them he said it'd be impossible to duplicate without much R&D. I'll check with him again.

I thought you had the "special" version of those rotors. I'm pretty excited now!

rx7tt95

Well talked to Carlos and he's ok with posting the picture. The images will be on the new website when it's up anyway. Also, one can't just "copy" this part without the proper research and equipment to complete the modification. Notice the sides where the rotor was lightened to 93-spec weight. The thickness of the rotor faces is much greater than the 93+ and are inherently stronger as a result. I'll be running these with 3mm Mazda OEM seals. Pic of an exhaust port as well. Not finished yet so he doesnt' give away any details. Just for display to show the quality and precision of the work.
Michel

550rwhprex

iTrader: (1)

WOW!!!!!! I never thought carlos would let that out.....

rob20rx7

iTrader: (1)

well its good that he does, in a way this is the only way his work can get outso people can purchase it from him

rx7tt95

When he first sent me the photos, that was my first question! But all the stuff is going up on the new web page regardless and it's impossible to duplicate what he's done just by looking at the pic.

I almost wish I were going for huge numbers to take full advantage of everything he's doing. I may or may not get a race gas tune just to see...I think the GT40 will support 500rwhp with the .94 hot side. I'm more interested in a really broad powerband with great boost response/spool.

rob20rx7

iTrader: (1)

are you gonna be at nasa this weekend? ill be going on saturday.

rx7tt95

Yes scheduled to go there to shoot. Just upgraded my camera gear as well. I think I'm coming down with something nasty though, courtesey of the 1 million snowbirds that flew into SW Florida last week...If I really start to get bad, I'll have to cancel.

ghostrx7

rx7tt95 where in fl do ya live at???

rx7tt95

Other side of the state. Southwest Florida.