pluto

Here's a dyno pull we did on one of our customer's car using the GT40R turbo with our manifold. The boost level with this pull is around 13.5psi (.95kg/cm2 on pfc and almost 1.0kg/cm2 on the boost gauge). The car was actually started to run lean (not as lean as it shows on the dyno) but it was starting to run lean so I let off at around 7krpm. We later find out the lean condition was caused by low on fuel while we were on the dyno (eventhough it shows 1/4 tank on the fuel gauge). We tuned the car up to 15psi on the street before dyno pulls and left it there until he does the dual pump setup before tuning for higher boost on race gas. We're expecting 500rwhp with this car at 20psi of boost. More dyno charts to come in the future

Here're the specs of the car

Gotham Stage 3 engine w/ balancing to 5 grams
Greddy 2 row I/C
Gotham GT40R turbo kit w/ single wastegate setup
midpipe w/ silencer
Blitz exhaust
ACT Extreme clutch w/ ACT flywheel
PFC
850cc/1600cc injectors
Defi link gauge system
HKS Twin Power
3 bar map sensor
MSD ignition wire
NGK racing plugs for leading

APEXL8T

Steve , I bought the single super pump from Gotham ....how much WHP will it handle? I changed from a cosmo and have designed everything for 500WHP around 20.
But you state his needs to go with two pump setup.
Thanks
Ito Port Motor
(2) 7 MSD &AL-2
780/1600 (Gotham)
TO4R
3.5 straight out
PFC
AERO FPR

Wargasm

Added this to my site...

http://dyno.zeroglabs.com/dyno.php

http://dyno.zeroglabs.com/graph.php?...1&SUBMIT=GRAPH

sk8world

iTrader: (5)

Steve, What was the AR on the exhaust side?

Asleep

Steve,

Is that with the .54 or .56 trim compressor wheel?

Tony

pluto

I'm not exactly sure of the reason for asking about the A/R or the trim. From memory, it was the .94 A/R? and a 64.xmm compressor wheel so i guess its a 56trim? It's bigger than my GR63 and smaller than my GR67 turbo

pluto

the pump we sell should be good to about 430rwhp, you can get more out of it 500rwhp by hard wiring the pump to a 12V battery and a better ground. Factory wiring isn't big enough to supply the current needed to support the hp level.

ghostrx7

Its amazing what a nice manifold will do with that turbo...

APEXL8T

Thats what Freddy and I did . Thanks Art

onefastrx7

Steve,

the dyno chart looks really good, but how far was the dyno afr from the actual afr?
It is dangerously lean...

Asleep

There were a number of GT40R turbos (is your a true Garrett GT40R?) that had 56 trim wheels on it. These were the early versions I am told. The most recent ones have a 54 trim commpressor wheels on them. Garrett was surprised that I had a 56 trim on mine and went into a fit trying to figure out the history of the turbo when I had to replace the compressor wheel.

The real world seat of the pants difference is quicker spool-up on the slightly smaller compressor wheel. Measured by my pants and logged on my laptop, 300-400rpm quicker spool-up in 4th gear runs from 2500-7000rpm.

pluto

Based on the wideband I was using, it did go as lean as 11.7:1 so I let off at 7krpm. mid-range was around 10.7:1 Their a/f was probably off by around 1.5 from looking at it.

pluto

Good question, I'm not exactly sure what trim is what since I didn't measure the exducer but it was the new version of the GT40R since it was purchased recently. We did get 15psi by 3800rpm on the street in 4th gear, just didn't really show it on the dyno and logged.

Asleep

I am seeing 22psi by 4400rpm in a 3rd gear pull.

pluto

That's good to know Tony. Do you have any dyno charts for your car? I know that you tune the car yourself but wasn't sure if you have done any dyno pulls on it since I haven't seen one from you posted anywhere.

From the plots that i compared from using the GT40R

http://dyno.zeroglabs.com/graph.php?...1&SUBMIT=GRAPH

it looks like both zkeller and sk8world were getting 20psi at above 5000rpm. Is there something different that you did compared to the other two guys to gain an additional of 600rpm in spool up?

I know that rx7tt95 runs a non-ball bearing journal w/ the greddy manifold so he doesn't really count but I'm trying to figure out how you could spool 600rpm sooner than the other two guys (especially in 3rd gear).

It would help tremdously to see your dyno chart for comparison purposes.

adictd2b00st

kinda related.........how do you think the 1.06 a/r would be in comparison? would u see any noticable improvement up top ?

Asleep

Steve,

The same thing was happening to me (5000rpm for >20psi) with the 56 trim and unrestricted oil pressure at the wheel. The 54 trim (and oil restrictor) brought it down to sub 4600rpm. Timing/tuning changes gave me my best of 4438rpm on 94 octane. This data was gathered in 3rd gear. Since I did both changes (wheel and oil restrictor) together I state those together.

I've had so many "developmental" issues with the turbo and the manifold (now its a leak at Vband/DP and between the T4 flanges) that I have never felt it was "done" to dyno. Nothing bad intended towards Aspec and Sean. Most of the issues are ones related to being the first GT40r kit and Garret issues. I think this turbo will spin quicker with a tweaked manifold. Do you have any pics of your manifold? Need any comparison testing done with it?

All I have is my logs (FC-Edit and Innovate) to go my for predicting HP. I am running out intercooler and injectors. I am seeing a large spike in IAT above 16psi(Apexi FMIC) and maxxing out the injectors at 10.7 AFR at >6000rpm (2x1650, 2x860, Bosch '044, rocky steady pressure).

I need:
1) a Greddy 3-row FMIC
2) 2x1000cc top feed primaries
3) Fix the new leaks
4) time and money!

Then I am ready to spin the rollers. Data suggests I have hit close to my goals of >500 at <20.

Being an engineer keeps me tweaking the sucker and refusing to believe it could be done.

Tony

Asleep

Not sure. I would estimate that it would have a such a negative effect on my ported engine that it really wouldn't make more up top.

Now on a bridge ported (maybe even half-B) engine I bet that sucker would ROCK!

adictd2b00st

hmmm..... cause i'm in the process of ordering one for my car right now. mine is just a street port, so nothing crazy...... my engine builder tells me that precision now offers a whole bunch of different options for the gt40r and that i should look into going that route. Any suggestions?

Asleep

If you can get me compressor and turbine maps for the wheel's that they are using I can tell you how it would compare to what I have right now. My porting is smaller than a race port. More like a street port.

pluto

Tony,
You can see our manifolds here

http://www.gothamracing.com/catalog/...roducts_id=851

We already did the comparison test since the owner of the car had the GT40R turbo kit previously and didn't like the spool up and power potential. With the current setup, he was suprised with the night and day difference.

ghostrx7

Here I was thinking I was the only one with problems with that kit, leaking vbands, manifold was banana shaped. Had to get the manifold machined flat, and changed the vband to a 4 bolt...problem solved...

adictd2b00st

thanks, i'll be sure to post up what info i can find

Asleep

Wow. Nice. Have any before and after numbers on the spool up? PM me a price for one with a T4 foot print and the single WG option, please. What is the I.D. of the piping?

Old Slow Coach

Did you happen to catch this thread?:https://www.rx7club.com/single-turbo-rx-7s-23/v-band-flange-gasket-467421/

Order a sheet of this gasket material and get yer tweak on!