70mm GTQ 3 bolt dyno numbers?

[GNBRETT]

Was curious to know what kinda numbers you guys were putting down on the dyno with one of these in either a 70 or 71. I have not seen any numbers from the new HPQ wheels either. I'm looking at the DBB version and wondering if a 76 in a DBB would satisfy my spoolup desires or if a 70 or 71 would be more appropriate for the street. The 76 that I have seems a little slugish to me.

I'm considering going to something smaller that spools up quicker since my car will be a street car vs. a race car.

I Will be switching over to a 4 bolt over the winter and getting a turbo to match but was thinking of getting one of the new 70mm or 71mm 3 bolt designs to use for the rest of the year and was looking for some feedback.

I Will be running Pump gas/Alky only and won't be running more then 25 PSI.

Any thoughts or feedback would be appreciated.

 

[ttypewhite]

9.1 @ 148mph in TSM trim at 3550 weight = 931whp

 

[forcefed3.8's]

I was debating the same turbos. I might be able to get my hands on a 76, but am worried about spool up on the street. I was thinking about a 70 or 71, but if I can get this 76 cheap, I figure why not. Can Precision convert a standard 76 to a DBB, and if so anybody know how much?

 

[GNBRETT]

I was debating the same turbos. I might be able to get my hands on a 76, but am worried about spool up on the street. I was thinking about a 70 or 71, but if I can get this 76 cheap, I figure why not. Can Precision convert a standard 76 to a DBB, and if so anybody know how much?

I looked into the same thing. It would be cheaper to buy a new one then convert. It's like $700-$800 for one of those DBB setups when converting. Unless you can get the turbo for $500 it's not worth it. Atleast that is what I have been told.

 

[GNBRETT]

9.1 @ 148mph in TSM trim at 3550 weight = 931whp

Yea there is just no getten around the fact the speeds ur generating with that turbo are insane. Impressive to say the least. Which one are you running? The 70 or 71?

 

[ttypewhite]

70GTQ for now

 

[forcefed3.8's]

I looked into the same thing. It would be cheaper to buy a new one then convert. It's like $700-$800 for one of those DBB setups when converting. Unless you can get the turbo for $500 it's not worth it. Atleast that is what I have been told.

Actually that isn't bad, considering it is probably $2100 or more for a DBB 76. Like you said it depends what I can get it for.

 

[bison]

TSM car that went 139mph had 683whp with a 70 GTQ.

 

[Louie L.]

Buick Grand National - Precision Turbo - Upgrade - GM High-Tech

 

[Eticket]

Louie,

Was this just your chance to plug your magazine right up????

oh.. in your data log picture.. do you know what the 2 wavy lines at the top of the screen were? THat looked odd to me.

FYI.. converting a non bb turbo to a dbb isn't cheap.. the center section is the most pricey part of a turbo as far as I know.

Cheers
John

 

[GNBRETT]

Buick Grand National - Precision Turbo - Upgrade - GM High-Tech

That was a great write up. Hadn't read that one before. Probably because that magazine rarely has TB articles in them. Kool.

 

[bison]

That was a great write up. Hadn't read that one before. Probably because that magazine rarely has TB articles in them. Kool.

They gave more coverage of TR's over the years than any other mag i can think of. Wish they used more realistic boost levels like 27-28 psi for those tests. Looks like they would have ran out of injector .

 

[Louie L.]

I dont think we would have run out of fuel. I could have jacked with the pressure and all sorts of stuff. But If i remember correctly Rick wanted a comparison of boost numbers that most readers could relate or were willing to use. Even in 2004 no many people were running the big boost numbers in the TR world. Stage 2 guys and TSM guys were going into the 30+ range, but that wasnt the norm.

Only if I could have had a PTC converter back then ! Im sure with a converter and boost in the 32-34 range it would have made just about 700.

 

[Louie L.]

Louie,

Was this just your chance to plug your magazine right up????

oh.. in your data log picture.. do you know what the 2 wavy lines at the top of the screen were? THat looked odd to me.

FYI.. converting a non bb turbo to a dbb isn't cheap.. the center section is the most pricey part of a turbo as far as I know.

Cheers
John

Hey that magazine article is my claim to fame.. Ill bring it up as long as the subject comes up..LOL!!!.. At least you have a TV show for yours!!!

I remember talking about the wiggle lines , but for the life of me cant remember what that was all about. I know that we did have some RPM pickup issues thru out the day. Thats why we made I believe 12 Dyno pulls that day. It was amazing it didnt spit a rod out.

 

[bison]

I dont think we would have run out of fuel. I could have jacked with the pressure and all sorts of stuff. But If i remember correctly Rick wanted a comparison of boost numbers that most readers could relate or were willing to use. Even in 2004 no many people were running the big boost numbers in the TR world. Stage 2 guys and TSM guys were going into the 30+ range, but that wasnt the norm.

Only if I could have had a PTC converter back then ! Im sure with a converter and boost in the 32-34 range it would have made just about 700.

At least 700. Maybe more. Its just struck me funny that they wanted to compare those turbos in a range where they typically wouldnt be run. I have never known anyone in TSM to run boost numbers that low. Actually i just got back from the Sunday beating i give my car. 26-27psi with the 66GTQ. I can relate to higher boost pressures:biggrin: . For a 231ci its a waste to run a 70 GTQ at those low boost numbers imo unless its got a lot of cam and is revving upwards of 6500. It also proves at those power levels the GTQ doesnt do much more than a p-trim. Once they hit 600whp the GTQ shows its advantage a lot more. Then again back then TSM was more of a street class. It is anything but that now.

 

[Louie L.]

I totally agree with you. But as you remember the old "only 23-24 psi" joke was in full effect back then. Lots of people actually believed that. As you saw the test had low 22 deg of timing. We gave up power on the dyno due to timing, but we did want to save the car. After the turbo test we also conducted a few experiments that only Rick, Cal and I kept the results to. Some of that info was just to prove rumors, some was just curiosity.

When I showed up for the Bradenton race I ran it on low boost again.. 19-20 PSI and timing at 26 deg. Off the trailer and the foot brake it went 10.28 with a 1.55 60 ft.