Jesuscookies

iTrader: (1)

Okay folks,

Just like it says. If you had your choice of either turbo kit. which one would you pick and why?

POM HB

Money = no object. I'd go for GT serie for being BB. Newer technology from big company should be a good thing. R85 on the other hand should be very interesting....maybe even better than GT40R from the dyno sheet provided. Cheaper too. One thing tho, they said the price would be under 3K and it's now 3.15K. Not much different, but ...you know.

Poweraxel

its sort of hard to compare apples and oranges.. Looking at "Joe Smoe's" dyno and comparing to your car is total non-sense... someones dyno sheet that were all looking at could have different porting, boost, timing, fuel, etc.. than your car


i also see that alot of people looking at dyno sheets look for Max HP #'s.. looking at the Torque curve is more important!

in order to compare 2 turbos we really need to isolate the same condtions for both turbos(car,weather,boost,fuel,dyno, etc....)

you cant go wrong with either turbo though


good luck!

allrotor93

iTrader: (126)

i went with the r85 because demetrious put the thing through hell and it didnt even flinch. the only way to get a shaft as large as the once on the r85 is to step up to the gt42. my car will be the first on the dyno with the r85 so we will see a graph in the next week or so.

Jesuscookies

iTrader: (1)

Yes I agree, but to some extent the dyno will give you an idea of what the turbo is capable of, and what your car with similar porting, and tuning will acheive. I realize there are going to be many other variables involved, and this is just a rough estimate.

What do you think of the Torque curve on the R85? even if it is just a rough estimate. Wish I had a dyno of a GT40r to compare to.

Perfect, when are you and Sean setting that up? Seriously though, there are no GT40R Dynos available that I am aware of. You guys should put one out so others can have a better idea of how they behave on a rotary. It would probably go a long way in selling the kit.

Murphy's law says otherwise

Wargasm

I think that the R85 dyno looks very nice, but that's one car, built by D for selling his kit. I'd like to see how it works on a few more cars.... I also don't like "secret spec" turbos... I'd prefer to know exact part numbers for every component on that turbo.

Do you know the specs on yours allrotor93?

Either way, I'm looking forward to seeing some results on BOTH turbos in the list.

Jesuscookies

iTrader: (1)

Double Post

ErnieT

iTrader: (2)

I would pick the R85. Due to the fact that Demetrios has pushed that turbo to the limits and it's performance is proven on both the track and the dyno. He is one of the few tuners that actually provide a dyno sheet and dosen't leave it up to the public to speculate. Some may say car was built by him etc etc but at least he published the results.

The GT40 shaft is threaded into the compressor instead of passing all the way through with a reverse threaded nut on a large shaft like the r85. Many of these style turbos have backed off the compressor under high loads causing failures.

maxcooper

I think they both look like great setups. We'll have to wait until people have them on their cars before the dyno sheets start rolling in. I'll post mine when I have some with the R85, but I'm slow so it will probably be a few months.

I recently ordered the R85 kit, so that's what I voted for. These were the two kits I was deciding between. I really think they both sound outstanding. Both vendors seem trustworthy: A-Spec has a lot of happy customers, and I had met Demetrios back in 99 and he seems like a trustworthy guy that has been in the rotary scene for a long time. The R85 dynos prove that it can run well, and the GT40R compressor map and big turbine leads me to believe that it would be appropriate for my needs (decent spool and doesn't choke the engine at high RPM). The performance of both should be excellent, but we'll have to wait until people start dyno'ing with them to get a clear picture of how each performs on customer cars. I hate to say it, but for me it largely came down to price, both for the initial kit, and for repairs if/when I throw some seals at it.

After having the non-rebuildable, takes-forever-to-get-an-expensive-replacement RX6, the prospect of having some more economical and less time consuming repair or replacement options was important to me. Both the GT40R and R85 are a major improvement over the RX6 in this regard, but I think the R85 is the best of the two in this regard.

-Max

GoRacer

iTrader: (2)

I think Max would be a good test pilot for the R85. Not that Demetrious isn't but isn't he a full time racer? I think most of us are wannabe weekend warriors. The gt40R is only what $300 more and you get BB and water cooling which is very important to me. Hopefully someone will slap one on and we can compare it to Max's. Oh yeah, the inconel sounds great but it's very heavy. I think heat coating the BB wheels would be better. Max, heat coat the hot side before you slap that puppy on.

DCrosby

I have a lot of respect for Max, but the R85 kind of came at me from left field, and the 40R has been on my radar for a while, and unless I'm confusing things, there are a bunch of people out there with GT 40r's and it seems to be gathering a crowd... the 85 has one guy, which happens to be the same guy who's selling it.... not very convincing to me... but Max knows a lot more about rotaries than me...

ErnieT

iTrader: (2)

One of the main differences is that the one guy that developed the R85 seems to have a little more experience with high powered rotaries then most Not knocking anyone else but his experience trying many different style and size turbos is what achieved what to my knowledge is the highest rear wheel horsepower street ported turbo charged 13b. His dyno sheets for his car speak for themselves. I am not saying if you get the R85 you will make as much power as D does on his race car but what I am saying is the you are getting the same turbo technology that goes into his car.

This was the first turbo he hit 9's with when he ran a 9.8@141 without nitrous. There is no doubt in my mind when I get settled into my house and pic up another RX7 this is the kit I will use.

Jesuscookies

iTrader: (1)

I am also very curious about the spool characteristics of both of these turbos. I was told that the GT40R would have full boost within 300RPM of the GT35/40, or at about 3700RPM. This sounds great, but is this number a little too optimistic? When will the R85 Reach full boost? And will either of them be as laggy as a T78?

GoRacer

iTrader: (2)

I think the 40R will be more streetable then the R85. I don't really understand why the 35/40 is called a 35R when it uses a regular 40 wheel on the hotside. Isn't the 35R a full BB? That would make the 35/40 a 1/2 BB 35/40 and not a full BB 35R. So what was the point of that? Well the 40R is full BB and should spool as quick as the 35/40 or we shall see. Anyhow, yes Demetrios is the man but was the original poster looking for a drag setup or street/strip setup? I think the R85 will have more spool delay, especially with an inconel exhaust wheel.

allrotor93

iTrader: (126)

the r85 dyno was on a streetported 13b with an aftermarket intake manifold. i have the kit on my car but dee still has to tune it. he has already sold a handful without even having the prototype done. i think there will soon be a wait for the kit.

Jesuscookies

iTrader: (1)

Looking for best all around. I.E. streetable, able to bust an 11sec quarter mile, and full 15 psi worth of boost by 3500RPM

maxcooper

The 35R is full (dual) BB. So is the 40R. The 35R should spool a little bit faster than the 40R.

"35/40" is just another name for the 35R.

My guess is that the 40R will spool a little faster than the R85 (but I do not know for sure). But that is okay for me, especially since I think the 40R is going to spool very quickly.

-Max

rzograbian

either one you choose, you old turbo's are mine!! just tell me when!

btw, i voted for the 40R... (oh, im posting pics of the water injection now)

maxcooper

Thanks for the vote of confidence, Derek. I guess I have a sensitive radar. I swear I didn't see the R85 kit in one of my Mustang magazines.

I haven't seen any dynos for a GT40R yet. Michel had some for his GT40, but that is a different compressor.

No one has R85 dynos (besides D) because the turbo hasn't shipped yet. It sounds like I am not the only one with an order for one, though.

-Max

MeLoco

The only problem I see is that the dyno for the R85 is not with stock intake manifold that can make a big difference and the version he ran nines with is that the same turbo also? as far as dyno sheets they are good for reference points but they can and do get fudged. So I always wait and see a few to get a good idea before I just see one and say that must be the standard. We will have to see. But I'll be happy with my 40R as Im sure those who by the R85 will be.

MeLoco

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MeLoco

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Sponge Bob Square Pants

Where can one find more information on the R85? (besides the search function)

allrotor93

iTrader: (126)

www.kgparts.com

he did run 9s with this exact turbo. it only comes in one size. he is also selling the turbo kit that he uses on his race car.

ErnieT

iTrader: (2)

It is the same turbo he first broke into the 9's with and when he ran nines he was using the stock intake manifold.

Demetrios and Kieth have a dyno sheet using the stock manifold with the R85 at around 24psi and it shows 598rwhp wich is only 20rwhp shy of what he made with the upgraded manifold. He is just reluctant to post it because on one axis it shows MPH instead of RPM which may confuse people as the low boost runs are different and he doesn't want anyone questioning his integrity.