Interesting turbo/dyno test tonight= bigger isnt always better

[bison]

Which turbos? How big do you plan to go before you stop?

Were not going bigger. We did and it spooled like a turd. We are testing what we have available to us. Todays results are the most accurate yet. Ive made about 15 pulls in the last 3 hours and come to the conclusion i thought i would. One more turbo to go. So far tonight ive tested the 6176 journal .63 Garrett as a baseline, the 6262bb .63 Precision, and the 6376 journal .63 Precision

 

[rag231]

Since my first answer was obviously wrong I will try again, the valve to piston quench height was changed. To bring the valve closer to the piston. Reduction in detonation and improve the airflow in the combustion chamber.

 

[John Wilde]

Indexing the spark plugs.

 

[Rodney87GN]

Switched to a PTC converter.

 

[Squid4life]

no hard parts replaced

Is it your super secret port work with the mismatch in port size from the intake to the head? I remember seeing that a while back. Intake was not ported as much as the heads if I remember right...

 

[Squid4life]

Were not going bigger. We did and it spooled like a turd. We are testing what we have available to us. Todays results are the most accurate yet. Ive made about 15 pulls in the last 3 hours and come to the conclusion i thought i would. One more turbo to go. So far tonight ive tested the 6176 journal .63 Garrett as a baseline, the 6262bb .63 Precision, and the 6376 journal .63 Precision

Bison, speaking of spooling like a turd, I would be interested to see if you took a "typical" GN/T (mid 11ish) and stick a set of Hooker headers on. A lot of talk about poor performance, but never dyno results. Let me know if you would ever have time, I have a set on the shelf.

 

[Onalky87]

Bison, speaking of spooling like a turd, I would be interested to see if you took a "typical" GN/T (mid 11ish) and stick a set of Hooker headers on. A lot of talk about poor performance, but never dyno results. Let me know if you would ever have time, I have a set on the shelf.

Someone already brought this up I believe. But its a big job and to time consuming..plus Brian prob already knows the answer.

What about headers on a car with my setup Brian? Worth it or am I still to slow to need them

 

[Onalky87]

Bison, speaking of spooling like a turd, I would be interested to see if you took a "typical" GN/T (mid 11ish) and stick a set of Hooker headers on. A lot of talk about poor performance, but never dyno results. Let me know if you would ever have time, I have a set on the shelf.

Someone already brought this up I believe. But its a big job and to time consuming..plus Brian prob already knows the answer.

What about headers on a 128mph car like my setup Brian? Worth it or am I still to slow to need them

 

[bison]

Guys im not posting anything in this thread unless its related to the original topic. If i see one more off topic post here im not posting anything else here. All the off topic posts should be deleted. Not to sound like a dick but almost everything asked here has been covered at some point and guessing at what the difference was in the car that picked up a lot at the wheels after some simple changes isnt going to get me to respond more. The point of that particular post was that people need to start looking a lot further into what they have. Part of the reason why you see so many guys on here with the same combos and their times can vary by over a second. Its not luck that the quickest one with a particular combo is as quick as they are.

 

[turb0buick57]

haha, some of us are still interested in the dyno results to come..which turbo put down the best number tonight Bison?

 

[bison]

haha, some of us are still interested in the dyno results to come..which turbo put down the best number tonight Bison?

At 28-29psi they all made within 1% of each other. The 6262 made well over 30psi on the first pull. Boost was likely around 34-35psi. The turbos with Precision ex housings dont drop boost as rpm increases. A lot less back pressure at this level. The 6262BB spooled slightly faster than the 6176.

 

[tonysmach]

From #1 post:
"It conists of a stock internal short block with 8 to 1 compression
212 roller cam,stock steel heads with stock valves and some bowl work.
Precision front mount,single nozzle alky control kit,3" downpipe and dual 2.5 exhaust.
ALL TESTS WHERE DONE WITH 27#S OF BOOST 11.0-1 A/F and 21* TIMING."

Can you also add the stall on the torque converter of the test car? I did not see it but I did not read all 10 pages. LOL

 

[Jerryl]

At 28-29psi they all made within 1% of each other. The 6262 made well over 30psi on the first pull. Boost was likely around 34-35psi. The turbos with Precision ex housings dont drop boost as rpm increases. A lot less back pressure at this level. The 6262BB spooled slightly faster than the 6176.

I was trying to determine/back calculate the BP limitations for the different exhaust sides/combo's. It is interesting to see all of this.
Wish the thread was no cluttered with non-topic related posts. Makes it very cumbersome to "fish out" the info.

LOTS of work and $$ to complete the testing for sure.
VERY few have the ability to do this type of testing, and fewer will share this type of data.

Thanks for sharing your results!


.

 

[kshef]

The 6262 made well over 30psi on the first pull. Boost was likely around 34-35psi.

what kinda HP did it make?

 

[pontiac69fb]

At 28-29psi they all made within 1% of each other. The 6262 made well over 30psi on the first pull. Boost was likely around 34-35psi. The turbos with Precision ex housings dont drop boost as rpm increases. A lot less back pressure at this level. The 6262BB spooled slightly faster than the 6176.

If they all make within 1% of each other then the logical conclusion would be choose the one with the best spool right? So in theory either a BB turbo or one with the garret housing would be best for most street cars at or below this level. Is this correct?

 

[jasjamz]

I'm curious to know what the 6262 made at the 35psi too!

 

[DCVING 6]

I'm curious to know what the 6262 made at the 35psi too!

If its on the same motor as the 6167 probably not much more (the +/- 1%?) as the heads were the limiting factor.

 

[bison]

If its on the same motor as the 6167 probably not much more (the +/- 1%?) as the heads were the limiting factor.

I dont know the exact boost since i only used a 3 bar MAP to datalog with. I think it was 517whp peak on that pull but it carried it out the back a lot better than the 6176 since the 6176 hits backpressure and loses boost as the rpm climbs up. Running the same boost comparing any of the turbos tested that had 76 trim ex, 62 trim ex, and 65 trim ex wheels the power was within 1%. The 62 trim made boost very easily and could have been cranked over 40 psi. The later design ex wheels in Precision housings offer the lowest backpressure. However this reduction in backpressure does not correlate into extra power until the backpressure is great enough on the other turbos compared to cause a drop in boost from inadequate wastegate spring. This engine makes peak power right around 5100rpm. I tested the 6176, 6262, and 6376 within 2 hours of each other with everything else controlled the the boost was 28-29psi read on the same MAP sensor with the same targets and timing and the range was 491whp-496whp at those controlled levels for those 3. I could not get the boost over 25psi with the PT53 even after resurfacing the housing. With better heads the combos with the least backpressure will really start to make a lot more power. Im looking for a .63 p-trim ex housing for the 6176 so i can compare the power before and after. Peak will likely show nothing like it did last month with the .85 on there but it should pick up a lot where the backpressure starts to cause a drop off over 5300rpm. Wheel composition and size had little effect on this combo. As long as the compressor was big enough and the ex wheel/housing didnt cause a backpressure problem they make the same power. If i had a good set of heads on here the power would likely be in the 590 to 610whp range with the 7680, 6265, 6262, and, 6176 if it had a Precision housing on it. Ill be contacting those that offered their turbos for testing this week to get them included. I think they were the 6152 and TE45a.

 

[bison]

From #1 post:
"It conists of a stock internal short block with 8 to 1 compression
212 roller cam,stock steel heads with stock valves and some bowl work.
Precision front mount,single nozzle alky control kit,3" downpipe and dual 2.5 exhaust.
ALL TESTS WHERE DONE WITH 27#S OF BOOST 11.0-1 A/F and 21* TIMING."

Can you also add the stall on the torque converter of the test car? I did not see it but I did not read all 10 pages. LOL

2 days ago the test pressure was 28-29psi and i had a couple degrees more timing in there with 20* cooler ambient temps so we are seeing higher #'s on that day. I always baseline with the 6176 so we get a good idea of what to look for and make it easier to compare all the turbos since i cant re-test everything on the same day. All tests are on a 9.5" PTC. It stalls to about 3100@zero boost/vacuum and flashes to about 5000-5100 on the street under full power (28-29psi) The alkycontrol is a typo. This car still has the non progressive SMC with a 15gph nozzle but is getting an alkycontrol on it soon.

 

[jasjamz]

Since you started this, how many pulls do you think you have made on this car.
Did you encounter any issues that caused you to make any other changes to the car like trans issues, headgaskets, or that sort of stuff? It has had a tough time.