Borgwarner Twin Scroll 7670 With Dyno Graph
Sorry, I was asked twice and didn't answer. No I didn't drive it on the street, no registration, I tried to get Ben to drive it today because he commented on how well it idled and drove up on the trailer but he said he couldn't either.
The transient is going to be no better than the HTA3076 but I can tell you that is damn good too.
The transient is going to be no better than the HTA3076 but I can tell you that is damn good too.
Evolving Member
Joined: Jul 2003
Posts: 185
Likes: 0
From: Jamaica/FortLauderdale
Sorry, I was asked twice and didn't answer. No I didn't drive it on the street, no registration, I tried to get Ben to drive it today because he commented on how well it idled and drove up on the trailer but he said he couldn't either.
The transient is going to be no better than the HTA3076 but I can tell you that is damn good too.
The transient is going to be no better than the HTA3076 but I can tell you that is damn good too.
Evolved Member
Joined: Mar 2010
Posts: 715
Likes: 17
From: Welly NZ
Nice results all around, and awesome opportunity for this comparison.
I've been really impressed with what I've seen of the HTA series turbos, and had mentioned in other threads that I had a feeling that the EFR (and Garrett GTX for that matter) turbos may end up bringing too little too late once they finally start showing up - they are definitely very impressive, but I can't see myself buying one (or recommending one) to anyone given the supply issues, the price, and the fitment issues one is all but guaranteed to encounter. I'd love to know where the compressor design on them came from!
I've been really impressed with what I've seen of the HTA series turbos, and had mentioned in other threads that I had a feeling that the EFR (and Garrett GTX for that matter) turbos may end up bringing too little too late once they finally start showing up - they are definitely very impressive, but I can't see myself buying one (or recommending one) to anyone given the supply issues, the price, and the fitment issues one is all but guaranteed to encounter. I'd love to know where the compressor design on them came from!
I will agree here, weight is the one reason I haven't been too excited about the EFR stuff. The EFR turbos are light for what they are, but you can definitely go a lot lighter with the Tial housing setups.
The turbo does appear to be done on airflow on the high boost setting too, no argument there. I'm not convinced it's a hands-down win for the HTA for everybody. Not everybody cares about every pound in the car like you and I do, so that's less of an issue. There also has yet to be any form of test in the EVO community to show the transient response differences between the titanium turbine wheel and the twin scroll housing.
FWIW, I have an SAE document on the Mitsubishi EVO VI TME turbo testing done on the Titanium turbine wheel in that turbo. The data is very clear in their testing that the titanium wheel improved transient response by about 0.2 seconds when transitioning from off throttle to WOT slightly above the boost threshold point. That is pretty significant considering the transient condition was only like 1.0 seconds on the normal turbo and they were only running 1bar of boost. Higher boost would make for even larger improvements in spool as there is more energy available to compress air as less is taken up accelerating the wheel.
My answers are in caps mixed in your quote below:
I AGREE WITH THIS, WE DID THE TESTING TOO AND IT CAN PROBABLY BE FOUND ON HERE SOMEWHERE. IT WAS PERFORMED ON MY RS ACTUALLY, ON OUR DYNOJET, SO PRE-2005. WE DID SO MUCH TURBO TESTING THEN, TITANIUM WHEEL, CLIPPED WHEELS ETC. THE TRANSIENT WASN'T JUST BETTER, THE ENTIRE GRAPH WAS BETTER..........BECAUSE IT SPOOLS FASTER.
26 pounds is probably the turbo weight alone? I know the small frame 6258 with internal gate weighs in at 18 pounds. 12-15 pounds for a thick wall manifold, and 5-6 pounds for 2 external wastegates has you at 17-21 pounds without the turbo?
YES, I'D HAVE TO ASSUME THAT IS TURBO ONLY. I WANTED TO WEIGH OUR COMPETE KIT TODAY BUT IT SHIPPED. I WISH I HAD WEIGHED THE COMPLETE EFR SET UP.
Yep, I was pointing out the same thing, the HTA3076 is ahead on torque for a given boost level. Looks like the EFR does make the same HP up top though at a given boost level. The HTA appears to be able to run a higher overall boost pressure though, giving it the win in the real world either way.
AGREED AGAIN. BY TODAYS STANDARDS 30 PSI IS PRETTY LOW BOOST. I CAN TYPICALLY TUNE A GOOD STOCK TURBO SET UP ON PUMP GAS FOR A DAILY DRIVER AT 30 PSI.
Is the boost reference taken pre or post intercooler? If it's pre-intercooler, that would explain the boost drop at the lower boost settings. Also, it’s just one boost controller tee’d into two wastegates, right? Not two separate boost controllers...
BOOST WAS MEASURED ON BOTH CARS IN THE EXACT SAME SPOT IN THE INTAKE MANIFOLD PLENUM.
The turbo does appear to be done on airflow on the high boost setting too, no argument there. I'm not convinced it's a hands-down win for the HTA for everybody. Not everybody cares about every pound in the car like you and I do, so that's less of an issue. There also has yet to be any form of test in the EVO community to show the transient response differences between the titanium turbine wheel and the twin scroll housing.
BASED ON THE DYNO SHEETS I CAN NOT SEE THE TRANSIENT RESPONSE BEING BETTER WITH THE EFR. SPOOL UP IS SPOOL UP, IF IT'S LAZY IT'S GOING TO BE LAZY THE ENTIRE RPM, NOT JUST ON A SHIFT.
FWIW, I have an SAE document on the Mitsubishi EVO VI TME turbo testing done on the Titanium turbine wheel in that turbo. The data is very clear in their testing that the titanium wheel improved transient response by about 0.2 seconds when transitioning from off throttle to WOT slightly above the boost threshold point. That is pretty significant considering the transient condition was only like 1.0 seconds on the normal turbo and they were only running 1bar of boost. Higher boost would make for even larger improvements in spool as there is more energy available to compress air as less is taken up accelerating the wheel.
YES, I'D HAVE TO ASSUME THAT IS TURBO ONLY. I WANTED TO WEIGH OUR COMPETE KIT TODAY BUT IT SHIPPED. I WISH I HAD WEIGHED THE COMPLETE EFR SET UP.
Yep, I was pointing out the same thing, the HTA3076 is ahead on torque for a given boost level. Looks like the EFR does make the same HP up top though at a given boost level. The HTA appears to be able to run a higher overall boost pressure though, giving it the win in the real world either way.
AGREED AGAIN. BY TODAYS STANDARDS 30 PSI IS PRETTY LOW BOOST. I CAN TYPICALLY TUNE A GOOD STOCK TURBO SET UP ON PUMP GAS FOR A DAILY DRIVER AT 30 PSI.
Is the boost reference taken pre or post intercooler? If it's pre-intercooler, that would explain the boost drop at the lower boost settings. Also, it’s just one boost controller tee’d into two wastegates, right? Not two separate boost controllers...
BOOST WAS MEASURED ON BOTH CARS IN THE EXACT SAME SPOT IN THE INTAKE MANIFOLD PLENUM.
The turbo does appear to be done on airflow on the high boost setting too, no argument there. I'm not convinced it's a hands-down win for the HTA for everybody. Not everybody cares about every pound in the car like you and I do, so that's less of an issue. There also has yet to be any form of test in the EVO community to show the transient response differences between the titanium turbine wheel and the twin scroll housing.
BASED ON THE DYNO SHEETS I CAN NOT SEE THE TRANSIENT RESPONSE BEING BETTER WITH THE EFR. SPOOL UP IS SPOOL UP, IF IT'S LAZY IT'S GOING TO BE LAZY THE ENTIRE RPM, NOT JUST ON A SHIFT.
FWIW, I have an SAE document on the Mitsubishi EVO VI TME turbo testing done on the Titanium turbine wheel in that turbo. The data is very clear in their testing that the titanium wheel improved transient response by about 0.2 seconds when transitioning from off throttle to WOT slightly above the boost threshold point. That is pretty significant considering the transient condition was only like 1.0 seconds on the normal turbo and they were only running 1bar of boost. Higher boost would make for even larger improvements in spool as there is more energy available to compress air as less is taken up accelerating the wheel.
Evolved Member
Joined: Mar 2010
Posts: 715
Likes: 17
From: Welly NZ
Spool comes partly from the aerodynamic properties of the wheels etc, and partly from the inertia of them. When you use a dyno, the acceleration rate is controlled and may mask the influence inertia may have on a given turbo setup when compared with another.... realistically we don't do all our racing in 4th gear starting with a bit of brake boosting.
Imho its entirely possible to have two turbos which will build 10 psi flat out on a dyno set steady at 3000 rpm, but if you do a power run with a quick ish ramp rate you can see quite different spool characteristics and on road behavior.
Imho its entirely possible to have two turbos which will build 10 psi flat out on a dyno set steady at 3000 rpm, but if you do a power run with a quick ish ramp rate you can see quite different spool characteristics and on road behavior.
I meant the boost reference source for the boost controller. Does the line going to the Hallman come off the intercooler pipe before or after the intercooler?
If it's before, as you are probably aware, you'll get boost drop simply due to the pressure drop across the intercooler. If it's tapped into the upper intercooler pipe, then it is irrelevant. Just a thought on the boost drop while at lower boost levels where it really shouldn't be dropping boost.
Yeah, I'm very curious on the weight of your setup. I have a 1-1/2" schedule 10 manifold with ~18" long runners and I think it weighed in around 14 pounds, it's been a while though so I could be off. I think a thin wall setup could probably get around 6-7 pounds with similar runner lengths. If the GT30 turbo in the Tial housing is only 10-12 pounds and a single gate...that's a pretty significant weight savings from in front of the front axle.
Last edited by 03whitegsr; Oct 31, 2011 at 08:48 PM.
Spool comes partly from the aerodynamic properties of the wheels etc, and partly from the inertia of them. When you use a dyno, the acceleration rate is controlled and may mask the influence inertia may have on a given turbo setup when compared with another.... realistically we don't do all our racing in 4th gear starting with a bit of brake boosting.
Imho its entirely possible to have two turbos which will build 10 psi flat out on a dyno set steady at 3000 rpm, but if you do a power run with a quick ish ramp rate you can see quite different spool characteristics and on road behavior.
Imho its entirely possible to have two turbos which will build 10 psi flat out on a dyno set steady at 3000 rpm, but if you do a power run with a quick ish ramp rate you can see quite different spool characteristics and on road behavior.
The pressure drop across the FMIC is low, both cars have our Race FMIC on them. I've done pre/post pressures on the Race FMIC on my car with map sensors a few years ago. I'm sure I don't have the notes or logs so I have to go off the top of my head. I seem to remember the testing was done in the low 30 psi range and the difference was at or less than 1 psi. This was done when we were also measuring back pressure in the turbine housing.
To answer you though, the EFR has the boost source on the compressor housing. My car has the boost source at the intake plenum.
To answer you though, the EFR has the boost source on the compressor housing. My car has the boost source at the intake plenum.