Gotham Racing GR67 dyno numbers
12-15-05, 10:03 AM
#1
Gotham Racing GR67 dyno numbers
A few months ago I purchased the GR67 turbo kit from Gotham racing. My old turbo setup was giving me issues and I had enough. When I reveived the GR67 kit I was amazed at the craftsmanship, it's truely top notch. I got the dual wastegate option and a hot side of 1.0 incase anyone was gonna ask.
My old turbo kit consisted of an innovative T-66 dual ball bearing with a .84 hot side and an HKS cast manifold with HKS wastegate.
The install on the GR67 was much more straight forward then my old kit. Everything was easily accessable and bolted in easily. The only problem I had was with my V-mount. The core sits fairly close to the turbo once everything is bolted up. Luckily I found a K&N filter that fit perfectly, so it does work with a V-mount. Once everything was bolted up Steve Kan was called in for tuning. We took my car out on the highway and tune for 15.5 lbs, but it should be safe up to 17 if i so choose.
The first thing I noticed about the new turbo is how fast and strong it spools up. Eventhough the new turbo is non ball bearing and a 67mm compressor housing with a 1.0 hot side it spooled up quicker then my old setup. My old setup would get about 10lbs of boost at 4,000rpms in 4th...the new one gets 9lbs at 3,000rpms in 4th, and when this one hits...it hits hard! I would strongly recommend this turbo, it's got great bottom end and rock solid top end, this sucker pulls hard all the way to redline.
Okay so here is what everyone probably just skipped over my reading to see.
Old turbo at 16.5 psi with A/Fs in the 10s (4th gear i believe)
GR67 at 15.5 psi in 3rd gear
On the dyno
Just a little pic
My old turbo kit consisted of an innovative T-66 dual ball bearing with a .84 hot side and an HKS cast manifold with HKS wastegate.
The install on the GR67 was much more straight forward then my old kit. Everything was easily accessable and bolted in easily. The only problem I had was with my V-mount. The core sits fairly close to the turbo once everything is bolted up. Luckily I found a K&N filter that fit perfectly, so it does work with a V-mount. Once everything was bolted up Steve Kan was called in for tuning. We took my car out on the highway and tune for 15.5 lbs, but it should be safe up to 17 if i so choose.
The first thing I noticed about the new turbo is how fast and strong it spools up. Eventhough the new turbo is non ball bearing and a 67mm compressor housing with a 1.0 hot side it spooled up quicker then my old setup. My old setup would get about 10lbs of boost at 4,000rpms in 4th...the new one gets 9lbs at 3,000rpms in 4th, and when this one hits...it hits hard! I would strongly recommend this turbo, it's got great bottom end and rock solid top end, this sucker pulls hard all the way to redline.
Okay so here is what everyone probably just skipped over my reading to see.
Old turbo at 16.5 psi with A/Fs in the 10s (4th gear i believe)
GR67 at 15.5 psi in 3rd gear
On the dyno
Just a little pic
12-15-05, 12:41 PM
#7
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Nice numbers!
I do have one question though....
Why does it cross over at around 6600rpm? Correct me if I'm wrong but isn't crossover normally around 5250? Wouldn't this throw off the readings?
I do have one question though....
Why does it cross over at around 6600rpm? Correct me if I'm wrong but isn't crossover normally around 5250? Wouldn't this throw off the readings?
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12-15-05, 02:05 PM
#8
Thanks everyone.
Broken09...I believe thats the way Steve designed the manifold actually. He will post in here later I'm sure.
The front bumper is made by Vertex, I'm thinking about painting the hood to match the rest of the car...it's a tough decision.
-Dan
I've got video to post too, I just have to find someone to host it.
Broken09...I believe thats the way Steve designed the manifold actually. He will post in here later I'm sure.
The front bumper is made by Vertex, I'm thinking about painting the hood to match the rest of the car...it's a tough decision.
-Dan
I've got video to post too, I just have to find someone to host it.
Last edited by Scrub; 12-15-05 at 02:08 PM.
12-15-05, 03:32 PM
#11
development
Originally Posted by Scrub
Thanks everyone.
Broken09...I believe thats the way Steve designed the manifold actually. He will post in here later I'm sure.
The front bumper is made by Vertex, I'm thinking about painting the hood to match the rest of the car...it's a tough decision.
-Dan
I've got video to post too, I just have to find someone to host it.
Broken09...I believe thats the way Steve designed the manifold actually. He will post in here later I'm sure.
The front bumper is made by Vertex, I'm thinking about painting the hood to match the rest of the car...it's a tough decision.
-Dan
I've got video to post too, I just have to find someone to host it.
Great Car!! (just get a ps pulley now,
)
12-15-05, 06:36 PM
#12
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Originally Posted by twokrx7
Crossover point is at 5250rpm but it just doesn't appear to be so on the graph because the torque and hp scales are different
12-15-05, 06:53 PM
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basically what he is saying is that the scale on the left (torque) and the scale on the right (hp) are different, if you trace the torque curve at 5252rpm (which is approx 300ft-lbs) and trace the hp curve at 5252rpm (which is approx 300hp), the forumla still stands.
Originally Posted by Broken09
huh? I'm lost
12-15-05, 07:01 PM
#15
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Ride looks sweet bro! Congrats and no more oil pedistals! lol....Im happy Steve got it right for ya. That last turbo was dead after 5k. Ya gotta give me a ride in this one. BTW...I just ordered your bumper
12-15-05, 07:01 PM
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yea, i actually designed the manifold to peak torque at 6500rpm, but from looking at his boost curve, i think it was slowly dropping down causing it to peak torque earlier. any restriction on the exhaust path could also change the peak torque slightly. The way the dyno is loading the car could also vary as well. So based on his torque curve (which peaks at around 6200rpm), its pretty close to the original design goal. All of my customers who uses our manifold yields approx 6500rpm as the peak torque.
Here's a dyno chart using a GT40R turbo in place of the GR67 turbo using the same manifold and same motor porting. This is done at 13.5psi of boost
https://www.rx7club.com/single-turbo-rx-7s-23/gt40r-dyno-chart-474843/
Here's another car using a GT40 (4082 wheel). We proved that the turbo isn't big enough for the rotary engine to push over 400rwhp using this compressor wheel.
http://www.gothamracing.com/pics/Ste...yno%20pull.jpg
Here's another dyno chart from a different car using the GR67 turbo kit
http://www.gothamracing.com/pics/Ste...rbo%20kit1.jpg
Great numbers Dan!! it looks like the a/f meter on their dyno is slightly off since we tuned it to 11:1 a/f but overall, it looks nice a flat.
steve
Here's a dyno chart using a GT40R turbo in place of the GR67 turbo using the same manifold and same motor porting. This is done at 13.5psi of boost
https://www.rx7club.com/single-turbo-rx-7s-23/gt40r-dyno-chart-474843/
Here's another car using a GT40 (4082 wheel). We proved that the turbo isn't big enough for the rotary engine to push over 400rwhp using this compressor wheel.
http://www.gothamracing.com/pics/Ste...yno%20pull.jpg
Here's another dyno chart from a different car using the GR67 turbo kit
http://www.gothamracing.com/pics/Ste...rbo%20kit1.jpg
Great numbers Dan!! it looks like the a/f meter on their dyno is slightly off since we tuned it to 11:1 a/f but overall, it looks nice a flat.
steve
Originally Posted by dubulup
I think steve aimmed for max torque around 6krpm...which is where your peak showed up.
Great Car!! (just get a ps pulley now, )
Great Car!! (just get a ps pulley now,
)Last edited by pluto; 12-15-05 at 07:08 PM.
12-15-05, 09:43 PM
#20
Ernie, you suck...I can't believe you just ordered my bumper! Thanks for the kind words though
I'd like to put a big thanks out to Steve for all the hours we've spent talking on the phone about random crap, and all the tuning he's done for me in the past....definatley a great tuner and friend. Lookin forward to going out to Texas to check out the new shop next year.
I'd like to put a big thanks out to Steve for all the hours we've spent talking on the phone about random crap, and all the tuning he's done for me in the past....definatley a great tuner and friend. Lookin forward to going out to Texas to check out the new shop next year.
12-16-05, 08:21 AM
#21
Great numbers Dan! Glad to hear you got the car tuned and running to your liking. Can't wait to meet up with you guys again and see how my new turbo will compare to Gotham's set up.
Also, what time did Ramy get to your house the other night? I had 5 bucks that said he wouldn't get from mine to yours before 10:10. Just curious.
-Austin
Also, what time did Ramy get to your house the other night? I had 5 bucks that said he wouldn't get from mine to yours before 10:10. Just curious.
-Austin
12-23-05, 11:34 PM
#24
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Great numbers Danno . Seeing as how we made the same exact rwhp on the same exact dyno, I think we need to go out and run 'em and see who can shift mad quicker, lol. Of course, I needed more boost to do it, but that is why yours is bigger than mine 
P.S. The FD looks gorgeous. Two thumbs up
. Seeing as how we made the same exact rwhp on the same exact dyno, I think we need to go out and run 'em and see who can shift mad quicker, lol. Of course, I needed more boost to do it, but that is why yours is bigger than mine P.S. The FD looks gorgeous. Two thumbs up
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