GTX3071R or GTX3076R - 2.5 Litre?
#33
Drifting
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hi Sid,
unfortunately i have no data on exhaust back pressure. its something we probably should be testing though.
Pauly,
the gt3071 was a twin scroll housing i think it was somewhere around .83 although it could be 1.06 as it was changed later. Im not sure on the exact AR numbers but they are about what i am stating
the Gt3076 had the tial housings. a .62 to start with and later a .83. the dyno sheet i have is from when it was a .83
Sean
unfortunately i have no data on exhaust back pressure. its something we probably should be testing though.
Pauly,
the gt3071 was a twin scroll housing i think it was somewhere around .83 although it could be 1.06 as it was changed later. Im not sure on the exact AR numbers but they are about what i am stating
the Gt3076 had the tial housings. a .62 to start with and later a .83. the dyno sheet i have is from when it was a .83
Sean
#34
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
To put this in a bit of perspective and this is no disrespect to anyone involved in this thread, but the cars or engines were not exactly like for like, nor were the pulls done on the same day. I also think that the dyno operators being different, ramped up a little differently on the dyno. Not to mention the different exhausts and cams in all 3 motors.
However having said that, I also have to say that Sean's car with the VR3 kit is an excellent combination and could quite likely still be the best of the bunch on an equal level test. As demonstrated very ably here.
http://www.youtube.com/watch?v=75zV0VtQ8aE
However having said that, I also have to say that Sean's car with the VR3 kit is an excellent combination and could quite likely still be the best of the bunch on an equal level test. As demonstrated very ably here.
http://www.youtube.com/watch?v=75zV0VtQ8aE
#35
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
KKK-style turbines make more exhaust backpressure than GT turbines, hence the resulting wider torque band in low to mid rpm ranges, and hence GT turbines shining through in upper rpms and at boost pressures we cannot reasonably envisage on our tractor engines, well at least on the 8V versions.
Thanks for your input Sean, I will be sticking to my SPS Special for longer than I thought.
Thanks for your input Sean, I will be sticking to my SPS Special for longer than I thought.
#36
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
You have to test that motor with E85 and 23psi before you take it out! It just howls along on the track having watched that video again!!
#37
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Sean, thanks for the info - that is indeed thought provoking. Were you running the same piggyback & maps across the three different turbos?
I haven't definitvely excluded any turbo yet & I'm always open to a well-reasoned case. The one thing upon which I am adamant is going to stand-alone management so that I have full access to & control over the maps as my mods change.
I want to avoid proprietary chips where I'm locked out of the code & can't create custom maps - hence I'll probably go the Motec route as that's well supported here in the UK & in the classic motorsport sector in Europe generally.
It's a good point that our cars run relatively low boost & rpm compared to their modern Japanese counterparts - which can give a nice flat torque curve with the right turbo but can lower the ceiling on ultimate power. I can see that the GT series are perhaps optimised for higher boost levels than are generally viable for our cars, but then I'm after the best of all worlds (aren't we all !) of good midrange response on the track but also the best top-end I can get out of a 2.5 within sensible boost & rpm limits.
I'll definitely have a look at the Vitesse offering, but my question is how much of the Vitesse's performance was purely down to the turbo & how much should be attributed to the combination of the Vitesse maps running against their own turbo. If the Vitesse maps were run against the other turbos, that may have disadvantage them.
Either way, if i went the Vitesse route I'd still go Motec with custom maps as I don't want to be tied into a particular vendor's chips or mapping.
I haven't definitvely excluded any turbo yet & I'm always open to a well-reasoned case. The one thing upon which I am adamant is going to stand-alone management so that I have full access to & control over the maps as my mods change.
I want to avoid proprietary chips where I'm locked out of the code & can't create custom maps - hence I'll probably go the Motec route as that's well supported here in the UK & in the classic motorsport sector in Europe generally.
It's a good point that our cars run relatively low boost & rpm compared to their modern Japanese counterparts - which can give a nice flat torque curve with the right turbo but can lower the ceiling on ultimate power. I can see that the GT series are perhaps optimised for higher boost levels than are generally viable for our cars, but then I'm after the best of all worlds (aren't we all !) of good midrange response on the track but also the best top-end I can get out of a 2.5 within sensible boost & rpm limits.
I'll definitely have a look at the Vitesse offering, but my question is how much of the Vitesse's performance was purely down to the turbo & how much should be attributed to the combination of the Vitesse maps running against their own turbo. If the Vitesse maps were run against the other turbos, that may have disadvantage them.
Either way, if i went the Vitesse route I'd still go Motec with custom maps as I don't want to be tied into a particular vendor's chips or mapping.
#38
Drifting
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hi Penguinracer
the stage 3 and Gt3076 were running the Vitesse chip board and and Vitesse piggyback the gt3071 runs a Motec.
The maps between the Stage 3 and Gt3076 i think are quite close to each other, I have had the DME from the Gt3076 in our own car and noticed no Seat Dyno difference.. the Gt3071 and Motec are obviously different from the Vitesse software. But i know the Tuner of the Motec and in my opinion i have not seen anyone more experienced then him in Australia. Well besides Motec themselves. I can understand that you want complete control over your Maps but this doesnt always mean you are getting the most performance from the products on your car. i think the latest GT turbos are Great turbo's and may suit some engines perfectly but i also think John at Vitesse has tried and tested all of these turbos and taylored his turbos to suit your application.
The clip above is our own 951 Running E85 and 1.5bar boost(22psi) Motons and Hoosier slicks. first lap is a warm up lap.
Sean
the stage 3 and Gt3076 were running the Vitesse chip board and and Vitesse piggyback the gt3071 runs a Motec.
The maps between the Stage 3 and Gt3076 i think are quite close to each other, I have had the DME from the Gt3076 in our own car and noticed no Seat Dyno difference.. the Gt3071 and Motec are obviously different from the Vitesse software. But i know the Tuner of the Motec and in my opinion i have not seen anyone more experienced then him in Australia. Well besides Motec themselves. I can understand that you want complete control over your Maps but this doesnt always mean you are getting the most performance from the products on your car. i think the latest GT turbos are Great turbo's and may suit some engines perfectly but i also think John at Vitesse has tried and tested all of these turbos and taylored his turbos to suit your application.
The clip above is our own 951 Running E85 and 1.5bar boost(22psi) Motons and Hoosier slicks. first lap is a warm up lap.
Sean
#39
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Sean, the control-freak in me likes transparency as to what he's buying e.g. who made the turbo, what is the compressor spec, the turbine spec, what is the hotside A/R? etc
It interests me that your 3071 started falling behind your 3076 on the 2.5 which seems contrary to the advice to use the smallest possible compressor for your boost/rpm limits before you hit the map's choke line.
I believe there's a feeling (but we're yet see the evidence in a 951) that the GTX3071R will combine the top-end flow capacity of the GT3076 with the spool characteristics of the GT3071.
I'm going to a 70mm throttlebody, big-valve N/A head & aftermarket intake in the interests of increasing top-end flow as these motors have power & torque characteristics not far removed from those of a modern high pressure direct-injection turbo-diesel!
There are so many ways to skin this particular cat!
It interests me that your 3071 started falling behind your 3076 on the 2.5 which seems contrary to the advice to use the smallest possible compressor for your boost/rpm limits before you hit the map's choke line.
I believe there's a feeling (but we're yet see the evidence in a 951) that the GTX3071R will combine the top-end flow capacity of the GT3076 with the spool characteristics of the GT3071.
I'm going to a 70mm throttlebody, big-valve N/A head & aftermarket intake in the interests of increasing top-end flow as these motors have power & torque characteristics not far removed from those of a modern high pressure direct-injection turbo-diesel!
There are so many ways to skin this particular cat!
#40
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
If you want to play with your car and it sounds like you do, once you change to gt style turbo it opens up a lot more options for the future. Sean is referring to one of the early tunes of my 3071 here, but the turbo I use now outperforms it. There is some good options with billet wheels available these days.
#41
Burning Brakes
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Sean, thanks for the info - that is indeed thought provoking. Were you running the same piggyback & maps across the three different turbos?
I haven't definitvely excluded any turbo yet & I'm always open to a well-reasoned case. The one thing upon which I am adamant is going to stand-alone management so that I have full access to & control over the maps as my mods change.
I want to avoid proprietary chips where I'm locked out of the code & can't create custom maps - hence I'll probably go the Motec route as that's well supported here in the UK & in the classic motorsport sector in Europe generally.
It's a good point that our cars run relatively low boost & rpm compared to their modern Japanese counterparts - which can give a nice flat torque curve with the right turbo but can lower the ceiling on ultimate power. I can see that the GT series are perhaps optimised for higher boost levels than are generally viable for our cars, but then I'm after the best of all worlds (aren't we all !) of good midrange response on the track but also the best top-end I can get out of a 2.5 within sensible boost & rpm limits.
I'll definitely have a look at the Vitesse offering, but my question is how much of the Vitesse's performance was purely down to the turbo & how much should be attributed to the combination of the Vitesse maps running against their own turbo. If the Vitesse maps were run against the other turbos, that may have disadvantage them.
Either way, if i went the Vitesse route I'd still go Motec with custom maps as I don't want to be tied into a particular vendor's chips or mapping.
I haven't definitvely excluded any turbo yet & I'm always open to a well-reasoned case. The one thing upon which I am adamant is going to stand-alone management so that I have full access to & control over the maps as my mods change.
I want to avoid proprietary chips where I'm locked out of the code & can't create custom maps - hence I'll probably go the Motec route as that's well supported here in the UK & in the classic motorsport sector in Europe generally.
It's a good point that our cars run relatively low boost & rpm compared to their modern Japanese counterparts - which can give a nice flat torque curve with the right turbo but can lower the ceiling on ultimate power. I can see that the GT series are perhaps optimised for higher boost levels than are generally viable for our cars, but then I'm after the best of all worlds (aren't we all !) of good midrange response on the track but also the best top-end I can get out of a 2.5 within sensible boost & rpm limits.
I'll definitely have a look at the Vitesse offering, but my question is how much of the Vitesse's performance was purely down to the turbo & how much should be attributed to the combination of the Vitesse maps running against their own turbo. If the Vitesse maps were run against the other turbos, that may have disadvantage them.
Either way, if i went the Vitesse route I'd still go Motec with custom maps as I don't want to be tied into a particular vendor's chips or mapping.
I have Motec, but if you want a really nice plug and play option the standalone kit I saw that Thom bought recently from Pauer tuning is really nice and totally plug and play for the 951. If this had been around when I bought my Motec it would have got some serious consideration. It does everything you need for a 951 and more and you will get a map to start it from out of the box, matched to a set of injectors. Worth a lot in my book.
#43
Burning Brakes
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Not painful, but there is a lot of work to get the loom integrated with the factory system, get all the sensors setup, get everything taking to each other. Losing the MAF and getting the MAP installed, choosing and setting up COP/ Coils or coilpack etc etc. Then there is the initial startup and calibration. Add all that up and its a few quid, thats before you even get to tuning it. There is a lot to be said for plug and play and a set of tried and tested, matched components to sew it all together. If it works, why try and reinvent the wheel?
Motec is for sure a superior product but its a blank canvas designed to work on a basic car all the way up to a full on race spec machine with every option yuo can think of so unless you know someone who has done all the hard work its a steep learning curve.
Of course I can tell you what I have done on my car and what sensors etc I have used and you are welcome to my initial calibration map which will get you started, but unless you are setup identically to me the startup settings may not work for you. Depends on the triggers you use, crank sensor, ref sensor etc etc.
Motec is for sure a superior product but its a blank canvas designed to work on a basic car all the way up to a full on race spec machine with every option yuo can think of so unless you know someone who has done all the hard work its a steep learning curve.
Of course I can tell you what I have done on my car and what sensors etc I have used and you are welcome to my initial calibration map which will get you started, but unless you are setup identically to me the startup settings may not work for you. Depends on the triggers you use, crank sensor, ref sensor etc etc.
#44
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
The Vi-PEC kit from Vic at Pauertuning was the exact product I was looking for, as it comes complete with a superb wiring harness made to the customer's spec and that connects to all factory sensors, and everything else needed to jump in the car and drive after some very basic checks have been done.
Everything in the kit made for perfect installation and Vic has offered A1 technical support. The Help files in the Vi-PEC software have been very helpful at shedding some light on tuning points and other engine-related technical subjects that were rather obscure to me before.
As I said on the PCGB forum I wouldn't have made the jump to a standalone if like Nick I had to start from scratch and make my own wiring harness with aftermarket sensors. Just too much hassle for me. I love switching turbos, exhausts, intercoolers, but I equally loathe fiddling with wires.
The kit I specced from Vic did not come out cheap as I went wild with a full sequential set up and additional monitoring equipment, but even then I feel it's the best money I have ever spent on my car to the point that if ever I get another 951 that will be a car that will remain mechanically 100% stock and to which the only upgrade will be Vic's Vi-PEC kit.
Bar the programming, the factory turbo S hardware set up is very good and performs very well together, it's not easy to surpass its homogeneity without increasing displacement (thus spending a lot of $$$$), meaning upgrading the ECU may turn out as the best mod to do in the first place for the technically-minded guy who just got his 951.
Some may argue that most DME-derived stuff from other vendors may perform just as well in terms of peak power/torque delivery, but a standalone also brings the 951 into 21st century in general driving comfort, which, as a 951 guy who uses his car in all weather, I rate quite highly.
ETA : more info from the horse's mouth on the RW forum
http://reutterwerk.com/forums/showthread.php?t=20754
Everything in the kit made for perfect installation and Vic has offered A1 technical support. The Help files in the Vi-PEC software have been very helpful at shedding some light on tuning points and other engine-related technical subjects that were rather obscure to me before.
As I said on the PCGB forum I wouldn't have made the jump to a standalone if like Nick I had to start from scratch and make my own wiring harness with aftermarket sensors. Just too much hassle for me. I love switching turbos, exhausts, intercoolers, but I equally loathe fiddling with wires.
The kit I specced from Vic did not come out cheap as I went wild with a full sequential set up and additional monitoring equipment, but even then I feel it's the best money I have ever spent on my car to the point that if ever I get another 951 that will be a car that will remain mechanically 100% stock and to which the only upgrade will be Vic's Vi-PEC kit.
Bar the programming, the factory turbo S hardware set up is very good and performs very well together, it's not easy to surpass its homogeneity without increasing displacement (thus spending a lot of $$$$), meaning upgrading the ECU may turn out as the best mod to do in the first place for the technically-minded guy who just got his 951.
Some may argue that most DME-derived stuff from other vendors may perform just as well in terms of peak power/torque delivery, but a standalone also brings the 951 into 21st century in general driving comfort, which, as a 951 guy who uses his car in all weather, I rate quite highly.
ETA : more info from the horse's mouth on the RW forum
http://reutterwerk.com/forums/showthread.php?t=20754
Last edited by Thom; 05-13-2011 at 01:49 PM.
#45
Rennlist Member
Join Date: Feb 2003
Location: Chicago
Posts: 3,526
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hi Penguinracer,
Are you only limiting yourself to a choice between the turbos you have listed? We have had first hand experience with the gt3071 and the gt3076 as well as the Vitesse stage 3 and 5 all on 2.5ltrs. We have not used the GTX series so i cannot comment although my thoughts would be that there would not be a huge improvement on the GT series turbos.
As far as power usability is concerned the Vitesse stage 3 had the largest power band available. I will give you 3 examples i have from some dyno sheets we have
951 #1: Vitesse stage 3 kit 15psi 3 inch exhaust
951#2 : garrett gt3076 3-5 inch exhaust, vitesse chipboard and piggyback 22psi E85
951 #3: garrett Gt3071 3 inch exhaust 17psi
these figures are comparable as they were done on the same dyno. this dyno does read very low compared to the equivalent US units.
Vitesse stage 3 3000rpm 140whp
Garrett GT3076 3000rpm 60whp
Garrett GT3071 3000rpm 98whp
Vitesse stage 3 3500rpm 210whp
Garrett GT3076 3500rpm 100whp
Garrett GT3071 3500rpm 152whp
Vitesse stage 3 4000rpm 245whp
Garrett GT3076 4000rpm 195whp
Garrett GT3071 4000rpm 200whp
Vitesse stage 3 4500rpm 255whp
Garrett GT3076 4500rpm 254whp
Garrett GT3071 4500rpm 225whp
Vitesse stage 3 5000rpm 270whp
Garrett GT3076 5000rpm 270whp
Garrett GT3071 5000rpm 240whp
Vitesse stage 3 5500rpm 275whp
Garrett GT3076 5500rpm 285whp
Garrett GT3071 5500rpm 255whp
Vitesse stage 3 6000rpm end-whp
Garrett GT3076 6000rpm 290whp
Garrett GT3071 6000rpm 270whp
Personally i think the Vitesse stage 3 shines through here. its was only dynoed at 15psi.if it were dynoed at 17 it would produce i would imagine the same power if not more then the gt3071 and if were dynoed at 22psi with E85 i am sure it would produce more power again. infact if i get time before we swap our engine over to the 3.0ltr 16v i will get a dyno readout from the vitesse stage 3 on 20psi with E85 for good comparison. the power of the GT series seem to be lacking a little in the bottom end. From our results i would consider that the latest is not always the greatest and it may be worth to look at other alternatives
Sean
Are you only limiting yourself to a choice between the turbos you have listed? We have had first hand experience with the gt3071 and the gt3076 as well as the Vitesse stage 3 and 5 all on 2.5ltrs. We have not used the GTX series so i cannot comment although my thoughts would be that there would not be a huge improvement on the GT series turbos.
As far as power usability is concerned the Vitesse stage 3 had the largest power band available. I will give you 3 examples i have from some dyno sheets we have
951 #1: Vitesse stage 3 kit 15psi 3 inch exhaust
951#2 : garrett gt3076 3-5 inch exhaust, vitesse chipboard and piggyback 22psi E85
951 #3: garrett Gt3071 3 inch exhaust 17psi
these figures are comparable as they were done on the same dyno. this dyno does read very low compared to the equivalent US units.
Vitesse stage 3 3000rpm 140whp
Garrett GT3076 3000rpm 60whp
Garrett GT3071 3000rpm 98whp
Vitesse stage 3 3500rpm 210whp
Garrett GT3076 3500rpm 100whp
Garrett GT3071 3500rpm 152whp
Vitesse stage 3 4000rpm 245whp
Garrett GT3076 4000rpm 195whp
Garrett GT3071 4000rpm 200whp
Vitesse stage 3 4500rpm 255whp
Garrett GT3076 4500rpm 254whp
Garrett GT3071 4500rpm 225whp
Vitesse stage 3 5000rpm 270whp
Garrett GT3076 5000rpm 270whp
Garrett GT3071 5000rpm 240whp
Vitesse stage 3 5500rpm 275whp
Garrett GT3076 5500rpm 285whp
Garrett GT3071 5500rpm 255whp
Vitesse stage 3 6000rpm end-whp
Garrett GT3076 6000rpm 290whp
Garrett GT3071 6000rpm 270whp
Personally i think the Vitesse stage 3 shines through here. its was only dynoed at 15psi.if it were dynoed at 17 it would produce i would imagine the same power if not more then the gt3071 and if were dynoed at 22psi with E85 i am sure it would produce more power again. infact if i get time before we swap our engine over to the 3.0ltr 16v i will get a dyno readout from the vitesse stage 3 on 20psi with E85 for good comparison. the power of the GT series seem to be lacking a little in the bottom end. From our results i would consider that the latest is not always the greatest and it may be worth to look at other alternatives
Sean
Now, remap your timing table for each turbo and then report back. I think you'll see those little turbos spooling a good bit sooner. No disrespect, just keeping things real.