Who doesn't hug their car?

 

Once again, I totally understand your viewpoint. in all fairness, we dont tune cars, we dont build cars, we dont build motors, and we turn away almost all customer vehicle builds, SOLELY so we can focus on engineering and development. We have a 2wd dynapack we do 99% of our testing on, the other 1% is starting to be at sean ivey's dyno. I think people would rather see outside tuners on independant unbiased and respected dynos, regardless.

My best advice is that you need to drive a twinscroll equipped 35R. You clearly are familiar with your singlescroll 35R setup, until you have actually experienced and felt the difference that just the twinscroll hotside makes, its almost impossible to convey.

all the interest we've been getting for the past few months has been twinscroll 35R interest, so we dropped the 40R testing to do the 35R. 40R will be tested, but the 35R moved up in the priority chain. A 40R setup is fully capable of 780whp, especially using our twinscroll 4094R with our non-ac downpipe. that is in no way an unrealistic number. Sorry for the bad news, but we dont have these kits in stock, and we dont sponsor.

in some of the smaller turbos (30R) there might not be a huge (over 200-300rpm) difference in static full boost spoolup as seen on a dyno, but with 40R, 42R, and larger there is a very very significant difference from twinscroll to single scroll spool -- 800-1000rpm in the case of a 42R.

that is correct, a 4094 is rated to 780. i do prefer the 4088 as it can get to 760+whp maxxed out. A 37R setup would get absolutely destroyed by a twinscroll 4088R


those #s do seem a little high, but i have no doubt they are possible. judging by his powerband, there may be a bit more left in it if you increased plenum volume and changed turbine housings a little.

yes, very easy to do.

the 4088R's 63.5mm inducer might be smaller than the 66.7mm inducer of the 37R, but inducer is not everything!!! the 4088R exuducer is larger (88mm) as compared to the 84mm of the 37R. It is really a much bigger compressor wheel!! you can really see it when you hold the wheels next to each other. more importantly, the 4088R is a 7 blade compressor, not a 6 blade like the 37R... every revolution of that 7 blade compressor is moving much more air than an equivalently sized 6 blade...

you have no idea how capable the 40R really is. someday maybe we can prove it to you

i hope it doesnt get any weirder than that, your girlfriend might get really upset... j/k dan

 

CBRD is on board with full race now

cb

 

Thats what I think as well Geoff . Larger compressor wheel with extra blades and in a smaller trim , for those that don't know the GT4088R's C117 compressor is 88mm 52 trim where the T04R compressor (37R if people must call them that) is 84mm 63 trim .

Where the 4088R gets a big leg up is its large wheels (both sides) are in medium size trims where the BB T04R/T04Z/37R has a huge comp trim and a medium turbine trim . Technically the P trim was at the larger end of the T04 trim scale but still smaller than many GT turbines with that brain dead 84 trim size .

For ****s and giggles I'd like to see a T4R (same as T04Z but with a 60-1 comp) tested against a T04Z/37R . Old world compressor with 7/14 blades and 76mm 60T - at least they are a better speed match/trim match than the T04Z/37R IMO .
The HKS T04Z with is boutique housings may prove differently but personally I believe the "37R" is a huge victim marketing exercise by people who should know better at Garrett . True we do need better (smaller) turbine trim sizes than 84 but dinosaur T series turbines ? Spare me .

Your caustically , cheers A .

 

Small correction--all else being equal, fewer blades will result in more flow, but less pressure ratio capability. Of course, "all else being equal" never exists...

There are many many factors that play into a wheel's ultimate flow capability besides blade count (and wheel trim).

The 40R's wheel offers a lot of flow and high efficiency over a broad mass flow and pressure ratio range. A lot of mapwidth. It's a good wheel.

 

According to the maps, the 60-1 compressor will run into a significant disadvantage to a T04R compressor as the PR rises.

I agree in that the width of the efficiency islands in the map appear to make a GT40R a relatively 'broad spectrum' compressor with respect to varying displacements and VE. I might point out however that the T67 seems to work surprising well at high PR with these engines, perhaps because my calculations show that at a PR of 3, at 8500 rpm, moving from 80-95% VE will result in moving from ~50-60 lb/min, which happens to be in a very efficient spot for both GT40R and T67 compressors. If we change the displacement to let's say, 2.4L, the picture changes.

This being the case, I wouldn't argue for a minute that a GT40R has a superior compressor in general, but given what's indicated in the maps, one might need to consider the performance of the GT40 vs. T67 with several different vehicle platorms to reveal it.

 

So can somebody make an in car video of spool?

Us poorer folk would really appreciate it!

 

Thanks jay. getting even more off-topic, working with the 4094R lately, weve been pretty disappointed. some input from jeff evans (our tuner) --

i just tuned 4 cars with the twinscroll 4094r -- on all of them, Above 30psi, it barely made any more power than the 4088r. Even with the 1.19a/r housing, it only makes 30-40whp more. At 35psi boost was dropping back to 30psi (that is with the 1.19a/r housing), and IAT's went up another 50 degrees compared to running just 30psi. Even with the 1.06a/r housings boost still dropped off above 30psi pretty badly, and the power just was not there. This was on 3 honda engines, and a supra 2jz. The turbine does not flow enough to keep up with the compressor, regardless of the housing a/r. This turbo might work on a DSM or nissan well, but havent tried yet. I have tuned two virtually identical b-series engines running FR divided twin gate manifolds, same cams, displacement, compression, intake manifolds, exhaust, etc. They are close enough to do a good comparision. One was using the 1.06a/r, and the other a 1.19a/r on the 4094r. The spool was a tad bit slower with the 1.19a/r by about 200-300 rpms, and the power at 30psi was withing 20whp of each other. Above 30psi the 1.06a/r just didnt make any appreciable power, meaning for another 5psi of boost there was only 30-40whp increase... Its a large mismatch that "should" work, but just does not.

... all that being said, what do you think is going on? I am a sworn follower of the 4088R, but the 4094R just is a backpressure monster. Im interested in trying these out on 2.0 and 2.4L evos, but dont want to waste the time if the results are consistent with the supra and honda testing thus far

 

so geoff when are you guys going to come out with a manifold for bigger turbos ..i.e. 42r and s372 (with r cover specifically)...

 

so wats were the numbers on the dyno after installing the kit did i miss it???

 

We've been forever waiting for the GT4088R Dyno numbers on a EVO... It has not yet been done to my knowledge.

 

was there any numbers for the FR 35r kit?

 

All I've seen have been drag times on a 30R, evodan2004 is supposed to be dynoing the 30R and then switching to a 35R here soon!

 

here it is:



probably will be released in january '08

from what i heard, the car is finished. the dyno is supposed to be done shortly. The car is owned by a major g35/350z shop and the owner said he will post the results here. he is being quiet about it until the car is finished and dynoed. built motor, 40R, should be fun


yeah CBRD (chad block) will be dynoing evodans 30R, then swapping out to a 35R for a direct comparison. this is a 100% stock motor, just some cams and coil on plug. great initial test.

 

Based upon this test will dictate weather I got with the HTA 35R or your TS with the GT4088 turbo.. I can't wait for the results! May the best kit win!


I'm also interesting in seeing these results as I have been following them very closely!!!
-Thanks Geoff for the heads-up update!