Precision 6765 turbo too small at 20+ psi????
12-13-11, 06:26 PM
#28
Example http://youtu.be/KQsqJkboIdM
T04Z 13PSI -404 WHP on 91. Thats with 2000cc secondaries.
12-13-11, 06:47 PM
#29
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i made 400whp on a mustang dyno with a precision 6776e at 22psi. comparing dyno numbers is like comparing apples to oranges. i could made a small adjustment and make my car do 600whp. this was with 93 octane and no supplemental injection. engije is a 13b-re cosmo with 9.4:1 rotors and 800/1680 inj, hks cast manifold and 40mm wg.
12-13-11, 10:27 PM
#30
Senior Member
Interesting read, since you mentioned thrust bearing failure as the issue.
http://store.forcedperformance.net/m...otor%20Oil.pdf
http://store.forcedperformance.net/m...otor%20Oil.pdf
12-13-11, 11:30 PM
#31
Interesting read, since you mentioned thrust bearing failure as the issue.
http://store.forcedperformance.net/m...otor%20Oil.pdf
http://store.forcedperformance.net/m...otor%20Oil.pdf
12-13-11, 11:47 PM
#34
Not to de-rail this thread, i read that post the other day and after reading it i was surfing the net generously and decided to see about a case of BP b/c thats what i run. then i read..http://www.penngrade1.com/CMSFiles/F..._BRAD_PENN.pdf
04-09-12, 10:13 PM
#35
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Mate of mine made 391rwhp @ 12psi in his T04 powered rx4 coupe... but that was on our **** ozy 98 which is similar to your 93 from memory...
Dyno was a vain type Dyno Dynamics which has a bit of a tight **** figures wise...
Dyno was a vain type Dyno Dynamics which has a bit of a tight **** figures wise...
Significantly limited on 91 Octane.. the cap is 15psi. You wont make 400whp with a T04S or 35R even with my large porting without running high boost. So I was thinking the PT6765 was my best bet ideally rocking 13-14psi with my porting. Further info would be great. Searching my fingers off.
Example http://youtu.be/KQsqJkboIdM
T04Z 13PSI -404 WHP on 91. Thats with 2000cc secondaries.
Example http://youtu.be/KQsqJkboIdM
T04Z 13PSI -404 WHP on 91. Thats with 2000cc secondaries.
Last edited by ROT8WA; 04-09-12 at 10:21 PM.
04-18-12, 01:35 AM
#36
rotary sensei
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If you are running a 250 psi pump you are spraying 1162.50 cc's if your nozzle sizing is 930 cc's. The 250 psi pump increases the flow rate so you multiply nozzle size/cc by multiplying times 1.25. Did you factor that in?
Last edited by Mr rx-7 tt; 04-18-12 at 01:39 AM.
04-18-12, 09:08 AM
#37
Racing Rotary Since 1983
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the P6765 has a compressor wheel that is very similar in dimension to the A-Spec GT500, TO4Z and BW S300 63.
the PT6765 has an average area of 7 sq inches. and a trim of 63 just like the GT500, and TO4Z.
the 7 sq inch BW S300 63 differs in two areas, compressor trim at 52 V 63 for the other 67s, and turbine wheel sizing
the P6765 turbine wheel is only 5.885 sq inches in diameter which is 84% of the compressor area.
the BW S300 63 turbine is 6.31 sq inches or 90%. (1.0 A/R)
this might explain why my EGTs were stable, not climbing, at 1530 F between 4400 and 8600 at 24 psi and a touch over 500 SAE.
i agree w Turblown that you could use a larger hot side since the compressor can really crank out the hp. given that you want to run in the 30 psi neighborhood, and given a rotary requires significantly more flow than a piston engine, it could very well be your 5.885 (P trim) wheel is creating too much back pressure and heat which caused the thrust bearing failure. apex seal warpage also eventually occurs in such a situation.
i also share the concern over uneven P build quality.
as to the oil comments.... Robert Young's 2010 article just backs up my thread on the exact subject on our board in 2008... which was in response to an excellent tech article in Hot Rod mag.
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/you-need-know-about-reformulated-oil-revisited-again-july-08-a-770726/
i agree that we need the anti-wear additives that have been stripped from street oil. there are two options here, not one. instead of running race oil i choose to run Mobil One street oil for its superior heat resistance but i add 4 ounces of ZDDP+ to every oil change. i also consider two oil coolers (OE are fine) to be essential for any rotary running 20 PSI+
howard
the PT6765 has an average area of 7 sq inches. and a trim of 63 just like the GT500, and TO4Z.
the 7 sq inch BW S300 63 differs in two areas, compressor trim at 52 V 63 for the other 67s, and turbine wheel sizing
the P6765 turbine wheel is only 5.885 sq inches in diameter which is 84% of the compressor area.
the BW S300 63 turbine is 6.31 sq inches or 90%. (1.0 A/R)
this might explain why my EGTs were stable, not climbing, at 1530 F between 4400 and 8600 at 24 psi and a touch over 500 SAE.
i agree w Turblown that you could use a larger hot side since the compressor can really crank out the hp. given that you want to run in the 30 psi neighborhood, and given a rotary requires significantly more flow than a piston engine, it could very well be your 5.885 (P trim) wheel is creating too much back pressure and heat which caused the thrust bearing failure. apex seal warpage also eventually occurs in such a situation.
i also share the concern over uneven P build quality.
as to the oil comments.... Robert Young's 2010 article just backs up my thread on the exact subject on our board in 2008... which was in response to an excellent tech article in Hot Rod mag.
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/you-need-know-about-reformulated-oil-revisited-again-july-08-a-770726/
i agree that we need the anti-wear additives that have been stripped from street oil. there are two options here, not one. instead of running race oil i choose to run Mobil One street oil for its superior heat resistance but i add 4 ounces of ZDDP+ to every oil change. i also consider two oil coolers (OE are fine) to be essential for any rotary running 20 PSI+
howard
04-18-12, 12:53 PM
#38
the P6765 has a compressor wheel that is very similar in dimension to the A-Spec GT500, TO4Z and BW S300 63.
the PT6765 has an average area of 7 sq inches. and a trim of 63 just like the GT500, and TO4Z.
the 7 sq inch BW S300 63 differs in two areas, compressor trim at 52 V 63 for the other 67s, and turbine wheel sizing
the P6765 turbine wheel is only 5.885 sq inches in diameter which is 84% of the compressor area.
the BW S300 63 turbine is 6.31 sq inches or 90%. (1.0 A/R)
this might explain why my EGTs were stable, not climbing, at 1530 F between 4400 and 8600 at 24 psi and a touch over 500 SAE.
i agree w Turblown that you could use a larger hot side since the compressor can really crank out the hp. given that you want to run in the 30 psi neighborhood, and given a rotary requires significantly more flow than a piston engine, it could very well be your 5.885 (P trim) wheel is creating too much back pressure and heat which caused the thrust bearing failure. apex seal warpage also eventually occurs in such a situation.
i also share the concern over uneven P build quality.
as to the oil comments.... Robert Young's 2010 article just backs up my thread on the exact subject on our board in 2008... which was in response to an excellent tech article in Hot Rod mag.
https://www.rx7club.com/showthread.php?t=770726
i agree that we need the anti-wear additives that have been stripped from street oil. there are two options here, not one. instead of running race oil i choose to run Mobil One street oil for its superior heat resistance but i add 4 ounces of ZDDP+ to every oil change. i also consider two oil coolers (OE are fine) to be essential for any rotary running 20 PSI+
howard
the PT6765 has an average area of 7 sq inches. and a trim of 63 just like the GT500, and TO4Z.
the 7 sq inch BW S300 63 differs in two areas, compressor trim at 52 V 63 for the other 67s, and turbine wheel sizing
the P6765 turbine wheel is only 5.885 sq inches in diameter which is 84% of the compressor area.
the BW S300 63 turbine is 6.31 sq inches or 90%. (1.0 A/R)
this might explain why my EGTs were stable, not climbing, at 1530 F between 4400 and 8600 at 24 psi and a touch over 500 SAE.
i agree w Turblown that you could use a larger hot side since the compressor can really crank out the hp. given that you want to run in the 30 psi neighborhood, and given a rotary requires significantly more flow than a piston engine, it could very well be your 5.885 (P trim) wheel is creating too much back pressure and heat which caused the thrust bearing failure. apex seal warpage also eventually occurs in such a situation.
i also share the concern over uneven P build quality.
as to the oil comments.... Robert Young's 2010 article just backs up my thread on the exact subject on our board in 2008... which was in response to an excellent tech article in Hot Rod mag.
https://www.rx7club.com/showthread.php?t=770726
i agree that we need the anti-wear additives that have been stripped from street oil. there are two options here, not one. instead of running race oil i choose to run Mobil One street oil for its superior heat resistance but i add 4 ounces of ZDDP+ to every oil change. i also consider two oil coolers (OE are fine) to be essential for any rotary running 20 PSI+
howard
Id like to just sell the turbo and get a comp turbo. The turbo is freshly rebuilt so anyone interested let me know
04-18-12, 01:36 PM
#39
Significantly limited on 91 Octane.. the cap is 15psi. You wont make 400whp with a T04S or 35R even with my large porting without running high boost. So I was thinking the PT6765 was my best bet ideally rocking 13-14psi with my porting. Further info would be great. Searching my fingers off.
T04Z 13PSI -404 WHP on 91. Thats with 2000cc secondaries.
T04Z 13PSI -404 WHP on 91. Thats with 2000cc secondaries.
the 35R will make 450whp @14.5psi, proven. that was on a series 5 turbo motor as well with a more restrictive intake system and smaller port runners. granted it was a full bridged motor.
Last edited by RotaryEvolution; 04-18-12 at 01:41 PM.
04-18-12, 01:48 PM
#40
nelson will not tune past 15psi even with Injection, water or meth. he says he doesnt trust it, only race gas, but thats not what i want. maybe i'll ask again but that was what he told me last we spoke.
even 15psi on t04z or equivalent, i would run some sort of injection. the costs of injection is nothing compared to a well put together turbo kit...
even 15psi on t04z or equivalent, i would run some sort of injection. the costs of injection is nothing compared to a well put together turbo kit...
04-18-12, 04:34 PM
#41
hmm... The exhaust housing is a .96 non divided. I have heard that the non divided does not flow as well as a divided. My manifold is setup for a divided housing. If i step to a 1.0 divided housing do you think it would make that much difference? And if i stepped up to a 1.15 divided would that make much difference on spool?
Im running thru my options as I might be stuck with this turbo if it dont sell.
Im running thru my options as I might be stuck with this turbo if it dont sell.
04-18-12, 04:47 PM
#42
Pistons are for pussy's
silver i think just changing to a 1.0 divided manifold should fix the backpressure issue, as you have stated you have a dividied manifold with a tangenital housing, thus killing the point of the divided manifold.
I dont know you guys but here pretty much what people run is Precision and they swear by them. I just got my turbo a PT67/66 1.0 divided and im pretty confident its going to make great power. Whats holding me is that im planning on using 550cc primarys with ID2000 and dont know if thats enough fuel for 500whp.
I dont know you guys but here pretty much what people run is Precision and they swear by them. I just got my turbo a PT67/66 1.0 divided and im pretty confident its going to make great power. Whats holding me is that im planning on using 550cc primarys with ID2000 and dont know if thats enough fuel for 500whp.
04-18-12, 05:03 PM
#43
I switched from a .96 undivided with a divided manifold to a 1.32 divided and everything was better, full boost sooner, more power on the street, and full power to redline pretty much, peak power didn't really change but the power curve is much better.
04-18-12, 07:49 PM
#48
Racing Rotary Since 1983
iTrader: (6)
"im planning on using 550cc primarys with ID2000 and dont know if thats enough fuel for 500whp."
500 at 11 AFR at 85% duty cycle and 13% loss for lag is 4860 CC/Min.
if you want to run richer than 11 AFR you will need more or you could raise the pressure a touch.
running very small injectors in the primary and really large in the secondary is not ideal as you want an equal balance of fuel/air in each runner. an especially bad idea if you have significantly enlarged the primary ports/runners.
hc
500 at 11 AFR at 85% duty cycle and 13% loss for lag is 4860 CC/Min.
if you want to run richer than 11 AFR you will need more or you could raise the pressure a touch.
running very small injectors in the primary and really large in the secondary is not ideal as you want an equal balance of fuel/air in each runner. an especially bad idea if you have significantly enlarged the primary ports/runners.
hc
04-18-12, 08:42 PM
#49
Not sure with 500 primarys. I ran out of fuel at 24 psi last fall with a single supra pump with my 850/1680 injectors. I now have the supra pump feeding a genuine bosch 044 fuel pump to my 850/1680 injectors. Id like to get id1000's and id2000's but we will see how far this setup will go first