Twin GT28r Turbo Kit Pics
#176
"Challenged" since 1993
Join Date: Sep 2002
Location: Columbus, Oh
Posts: 540
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by bingoboy
so are you saying that it ran at 10psi? or did you get it to go at 15psi? because the posted dyno sheet seems rather disappointing for that setup running @ 15psi.
Me personally, I am interested in keeping the quick spool that allowed me to get out in front of all the big single FDs , 03 Cobras, and Vettes that I've run, and have enough top end to stay out in front to 120+.
#177
Lava Surfer
Join Date: Mar 2002
Location: Kailua, HI
Posts: 2,354
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Jason
Those runs were around 16psi and use a mustang Dyno which reads lower than a dynojet. HP would be over 400HP on Dynojet.
Jason
Jason
#178
NorCal 7's Co-founder
Nice numbers none the less. It's great to see the progress you guys have made. I'll be looking forward to seeing what the car does at higher boost levels.
When you mentioned that the car was still running rich, how rich are you talking?
Zach
When you mentioned that the car was still running rich, how rich are you talking?
Zach
#180
rain + FD = oops
Join Date: Jan 2005
Location: so Cal
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
keep in mind guys that this is on a race-ported engine. I'd like to see this same setup on a mild street port or stock port since I feel a lot of people interested in this kit want it because its more streetable than a t78 and still has the top end kick. But what is the point if you're running it on a race-ported motor - driveability suffers.
#181
Lava Surfer
Join Date: Mar 2002
Location: Kailua, HI
Posts: 2,354
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by fallenengel
keep in mind guys that this is on a race-ported engine. I'd like to see this same setup on a mild street port or stock port since I feel a lot of people interested in this kit want it because its more streetable than a t78 and still has the top end kick. But what is the point if you're running it on a race-ported motor - driveability suffers.
#182
Mm...I have an idea . Might be a stupid one . Why not run 2 separate boost controllers . One for each turbo . You can set one at a lower boost level and on at a higher boost level .
Would that help that help the low end while still having top power ?
Would that help that help the low end while still having top power ?
#183
Senior Member
iTrader: (1)
Originally Posted by SomeGuy_sg
Mm...I have an idea . Might be a stupid one . Why not run 2 separate boost controllers . One for each turbo . You can set one at a lower boost level and on at a higher boost level .
Would that help that help the low end while still having top power ?
Would that help that help the low end while still having top power ?
#184
Lives on the Forum
Originally Posted by Chaosx1
Sorry if this has already been mentioned but can they successfully be run sequentially? And what's the recommended boost? Thanks.
Do you even know what you are talking about?
-Ted
#185
Senior Member
Originally Posted by Rotarded
Peak horsepower #s are more for bragging rights and not necessarily indicative of performance. Most people interested in this set-up are interested in spool, and the area under the curve.
Me personally, I am interested in keeping the quick spool that allowed me to get out in front of all the big single FDs , 03 Cobras, and Vettes that I've run, and have enough top end to stay out in front to 120+.
Me personally, I am interested in keeping the quick spool that allowed me to get out in front of all the big single FDs , 03 Cobras, and Vettes that I've run, and have enough top end to stay out in front to 120+.
I agree. I like the area under this twin kit's HP and Torque curve. This is really nice for street and autocross. Can't wait to see the other dyno graph when it is fully tuned. Then later you can slap on a couple GT2871's! :o)
#187
Senior Member
Join Date: Jan 2004
Location: Colorado
Posts: 341
Likes: 0
Received 0 Likes
on
0 Posts
The 3071 will match a pp very nicely up to 30 psi at sea level. Waht hot side are you going with.....and I guess you changed your mind again about spending all this money on 2 turbos????
CW
CW
#189
Rotary Enthusiast
Join Date: Jun 2004
Location: Gallatin, TN
Posts: 1,457
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Marcel Burkett
I wonder how my twin GT3071 , semi pp. and jay-tech intake equipped FD will compare??
-Alex
#191
Senior Member
Join Date: Jan 2004
Location: Colorado
Posts: 341
Likes: 0
Received 0 Likes
on
0 Posts
What TO4e are those and whta are your post? I match up some super 50s to my engine but still scared about the fitting and pumbing.
Does anyone know how a single A/Rs and wheel size for a turbine relates to 2 turbos of smaller size?
CW
Does anyone know how a single A/Rs and wheel size for a turbine relates to 2 turbos of smaller size?
CW
#192
hmm so two gt30 with 71 trim should spool fine on extended street port right? looking for some .64 a/r....
hehe i wouldnt wanna do a whole project and end up worst then a single!!!
hehe i wouldnt wanna do a whole project and end up worst then a single!!!
Last edited by signofinfinity; 04-22-05 at 01:02 AM. Reason: forgot the air ratio
#194
Rotary Freak
iTrader: (4)
Join Date: Dec 2003
Location: pembroke, massachusetts
Posts: 2,534
Likes: 0
Received 0 Likes
on
0 Posts
I have a post about my turbos and setup in the 3rd generation section, thread is called "Just wanted to say thanks" https://www.rx7club.com/forum/showthread.php?t=417896 Im keeping the turbo specs quiet until I get dynoed, but they spool quick, anyone who says they wont hasnt physically driven a car with them, as for the plumbing, good luck its a royal pain, especially if you want true equal length manifold runners, add that to the true dual exhaust and it was a nightmare getting to fit.
#196
Rotary Freak
Join Date: Nov 2001
Location: trinidad and tobago
Posts: 2,715
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by teamafx
I have a post about my turbos and setup in the 3rd generation section, thread is called "Just wanted to say thanks" https://www.rx7club.com/forum/showthread.php?t=417896 Im keeping the turbo specs quiet until I get dynoed, but they spool quick, anyone who says they wont hasnt physically driven a car with them, as for the plumbing, good luck its a royal pain, especially if you want true equal length manifold runners, add that to the true dual exhaust and it was a nightmare getting to fit.
#199
Senior Member
Join Date: Apr 2001
Location: Seattle, WA
Posts: 528
Likes: 0
Received 0 Likes
on
0 Posts
Observations
Originally Posted by Kevin T. Wyum
"In complete theory"
That probably should have been incomplete theory : ).
A. The twins are not half the size.
B. A combined header, single turbo, will actually reduce the total amount of exhaust energy relative to two completely divided tubes and turbos.
C. I don't think you understand what I meant about rotating mass and distance from the point of rotation. It's not a linear relationship as you're thinking. It takes more effort to accelerate 1 large wheel than it does 2 small wheels.
D. Things don't equal out. With appropriately sized twins you will have faster spool, READ IMPORTANT, and the same top end flow as a large single.
The downside is you'll have a few pounds of additional weight and complication of all the coolant, oil, exhaust and intake lines/tubes and if equal quality a higher price.
If we want to nitpick there will be the additional benefits, minor as they may be, of more surface area to exchange heat in the center sections meaning likely longer turbo and system life, additional coolant and oil volumes to the system. They will likely run cooler.
That probably should have been incomplete theory : ).
A. The twins are not half the size.
B. A combined header, single turbo, will actually reduce the total amount of exhaust energy relative to two completely divided tubes and turbos.
C. I don't think you understand what I meant about rotating mass and distance from the point of rotation. It's not a linear relationship as you're thinking. It takes more effort to accelerate 1 large wheel than it does 2 small wheels.
D. Things don't equal out. With appropriately sized twins you will have faster spool, READ IMPORTANT, and the same top end flow as a large single.
The downside is you'll have a few pounds of additional weight and complication of all the coolant, oil, exhaust and intake lines/tubes and if equal quality a higher price.
If we want to nitpick there will be the additional benefits, minor as they may be, of more surface area to exchange heat in the center sections meaning likely longer turbo and system life, additional coolant and oil volumes to the system. They will likely run cooler.
However, the GT28R is not half of the size of a 35R nor are the efficiencies comparable among compressor and turbine maps. Number crunching indicates spool times should not be much better with twin 28Rs versus a 35R. For example, at 35R will make about 14 PSI at 3500 RPM. On a stock ported 13BREW, this equates to a pressure ratio of 2.2 (with conservative pressure drop) at 20 lbs/min (corrected). Using the same formula, but halving the flow for one rotor, a 28R will still have the same pressure ratio (As Max so eloquently pointed out), but have to do this at 10 lbs/min. The compressor maps say it ain’t so. We would expect 10 lbs/min at a pressure ratio of 2 or about 12 PSI. A ported motor will do better, but not necessarily in proportion to the enhanced flow rates. If you wanted the same boost response (with a stock port motor), the GT22/52 trim would fit the bill.
OTOH, the two GT28Rs will outflow the 35R but a good margin, so big HP can be expected from such a setup.
Turbine efficiencies are another story. Two 28Rs will prove more efficient and, again make more power.
In contrast to Kevin, I think this setup will generate a bit more heat than a single. The “larger surface area to exchange heat” using the twins will also require removal of that heat (exhaust temps to each turbo should roughly be the same as with a single, ceteris paribus). Additionally, since these turbos are roughly 2/3 to ¾ the size of a 35R each, the combined radiant surface area (compressor/turbine housings/downpipes) is greater resulting in higher under hood temperatures.
Back to your regularly scheduled program…
Gene
#200
Rotary Freak
Join Date: Nov 2001
Location: trinidad and tobago
Posts: 2,715
Likes: 0
Received 0 Likes
on
0 Posts
So whats the latest on this ?? , any more dyno numbers ? . I am finishing up my seup and would really like to see what this kit can do , so that I can get an idea of what to expect from mine ! , would I be making 500rwhp @ 15 psi ????
Last edited by Marcel Burkett; 06-18-05 at 08:30 PM.