More proof GTQ"S suffer on iron heads Read: Ttype white

[norbs]

below is a datalog same boost, same timing , same fuel map. It appears the demand for fuel is 5% less on the average. hence 5% less power which is in line with the .2 & 2mph loss i have seen. Results may vary.

 

[ttypewhite]

I see says the blind man. I wonder how that data will work with aluminum heads

 

[Louie L.]

Its Not the Q part that is messing up, but the 71 part.

 

[V6RACER]

Its Not the Q part that is messing up, but the 71 part.

I noticed the same thing with the BigStuff3 and the 71.. Anyone want to buy a GTQ71?

 

[salvageV6]

Sell it to Bamford.

Oh, wait, he already gave up on them.

Talk about your "garbage information."

 

[Louie L.]

Dont get me wrong. In my experience the 71 GTQ is a 10 sec turbo. But it doesnt make as much power a PTE 70 GTQ(Non ported shoud) does.

 

[ttypewhite]

I went back out last weekend with a Flat tappet 212, Champion iron heads & the GTQ71. I went 10.30's @ 132mph with a 1.50 sixty foot. I think its more the cam thats running out of steam rather then the turbo. If I could get a hyd roller or solid roller in its place then I believe I could utilize this turbo better. My slicks are 8 years old. So if I can get my sixty foots down to the 1.3's then I could see that 9 sec slip becoming more do-able (if such a word exists). Any thoughts?

 

[Joe Lubrant]

Dont get me wrong. In my experience the 71 GTQ is a 10 sec turbo. But it doesnt make as much power a PTE 70 GTQ (Non ported shoud) does.

Louie,

I agree, and made a post else where regarding the 70 GTQ vs 71 GTQ.

I stated that the 70GTQ will run as well, if not better than the 71GTQ, especially if the 70 is of the Non-Ported Shroud type.

It may have more to do with the Ported Shroud Compressor Cover, than the Wheel size/type it self. I made reference to the Official Garrett Web-Site, where they reflected that Ported Shroud Covers reduce effeciency slightly.

Ported Shroud Compressor Covers by design were basically to help eliminate/reduce Compressor Surge, but as they stated... slight reduction in efficiency. This slight reduction would have an impact on power.

If I were to run a 70GTQ, 71GTQ or 71X-Trim, it would be in a Non-Ported Shroud H-Cover configuration.

For those experiencing compressor surge issues in other senarios, do of course have the option to use the PS cover.

Joe

 

[norbs]

I am not here to knock anyone's turbo, but the facts are on my car the dfi pulls out more fuel with the gtq71 than the 70. I may just convert my 70 to a gtq and try that. I love how the gtq drives on the street. may have to just go that route. Or think i should just change the ported shroud cover?

 

[86brick]

below is a datalog same boost, same timing , same fuel map. It appears the demand for fuel is 5% less on the average. hence 5% less power which is in line with the .2 & 2mph loss i have seen. Results definitely vary.

Case in point, Roy and Laz this past weekend at Reynolds... They had the iron heads on the little 109 and went 9.65 @140mph running the XFI unit for the first time and had a bad converter..

 

[86brick]

Sell it to Bamford.

Oh, wait, he already gave up on them.

Talk about your "garbage information."

Really?

From T6P.com yesterday...

Brick, I put the PT 70 GTQ back on the car for this event. Based on the data collected the PT70 GTQ makes more power at lower boost levels. 9.00's are just around the corner. :rock:

Dave went 9.23 @147MPH this weekend at Reynolds in TSM trim with the PT70GTQ... Somebody correct me if I'm wrong but I don't believe he has gone that fast with the Innovative DBB 70Xtrim turbo..

 

[d0n_3d]

I normally don't even recommend a 71 for a Buick. That turbo is designed mainly for guys running high boost like 35 psi or more (Supras for example). I've always seen guys have much better results with the 70. It's more than enough turbo for the 109 block anyways IMO. But what do I know?

 

[V6RACER]

I normally don't even recommend a 71 for a Buick. That turbo is designed mainly for guys running high boost like 35 psi or more (Supras for example). I've always seen guys have much better results with the 70. It's more than enough turbo for the 109 block anyways IMO. But what do I know?

I was trying to run as much as I could with it.. Could only get 28-29 and it fell on the shifts 8 psi..

 

[norbs]

SO it looks like the ported shroud is the problem? So if i change this to a non ported shroud It will bring power levels back to 70 gtq specs?

 

[Joe Lubrant]

I normally don't even recommend a 71 for a Buick. That turbo is designed mainly for guys running high boost like 35 psi or more (Supras for example). I've always seen guys have much better results with the 70. It's more than enough turbo for the 109 block anyways IMO. But what do I know?

Don,... I just looked on the PTE web-site under BUICK TURBO's (3-Bolt), and it reflected the PT71 GTQ as the PTE specification offering??
What is sort of strange it does not list the PT70 GTQ, just the PT70 P-Trim?? ………..Might want to up-date that information for the public, to match your turbo recommendation??

Also not sure of your explaination, that the 71 is for mainly guy's running 35 psi or more, as opposed to a Buick with larger displacement & less boost?
Could you possibly elaborate with some specifics as to why?

I think most all understand the need for the higher boost levels, for smaller displacement engines (i.e. Supra's) to meet the air volume necessary for desired power.

As brought up in earlier post, can you (PTE) clarify pro’s & cons relating to P.S. compressor covers on either wheel configuration?

In addition, could you also provide the differences in flow/volume characteristics, at the different pressure ratios for each wheel (70mm vs 71mm), per a available/reference compressor map??

If you can address and/or provide information, relating to the above, it will surely help others in making a sound choice on selecting the right Turbo/CC for their specific application.

Joe

 

[norbs]

Good questions, hopefully a good answer, because I and many others are confused why the 71 does not work on "so many buicks"

 

[d0n_3d]

Well Joe, I am not in charge of the website but I do see that and I will address that. Thank you for pointing that out!

As far as compressor maps go, you know very well that Garrett does not release this information very freely and even I don't have access to such information. I wish I could give you a map!

In regards to the 71 deal on a Buick, I'm not trying to be technical, just stating I'd rather see a Buick run a 70 because that's what most people have run and have had better luck with. That's all. Maybe in SOME instances, the 71 might work better but why would you want to run one if you can run mid 9's on a 109 block with a 70??? It's more than enough turbo for a stock block. I can't see anyone argue-ing this point.

Also to be honest, we no longer sell a P-trim 70 and I will make a suggestion to take that off the spec sheet. Thanks guys.

 

[d0n_3d]

Oh yeah, in regards to the ported shroud issue, I don't know why you would lose horsepower running one? Has anyone done back to back testing? I haven't seen anyone in the Buick crowd do it (I could be wrong!). From other vendors testing on various different applications, there was no performance loss when using a ported shroud. The only design and function of a ported shroud cover is to eliminate compressor surge (which in all honestly, is mainly found on cars with smaller displacements than the 3.8's and that run manual trannys and run big turbos). Most of the Buicks I have ever seen usually don't even need a ported shroud.

I'm no engineer. I'm human and could be wrong on this, but this is just what I have seen and dealt with and please correct me if I am wrong! I'm not here to put down anyone. Just trying to get positive feedback on what is really going on out there.

 

[bird]

Well Joe, I am not in charge of the website but I do see that and I will address that. Thank you for pointing that out!

As far as compressor maps go, you know very well that Garrett does not release this information very freely and even I don't have access to such information. I wish I could give you a map!

In regards to the 71 deal on a Buick, I'm not trying to be technical, just stating I'd rather see a Buick run a 70 because that's what most people have run and have had better luck with. That's all. Maybe in SOME instances, the 71 might work better but why would you want to run one if you can run mid 9's on a 109 block with a 70??? It's more than enough turbo for a stock block. I can't see anyone argue-ing this point.

Also to be honest, we no longer sell a P-trim 70 and I will make a suggestion to take that off the spec sheet. Thanks guys.

times in my sig. are with a p-trim 70 and 30 psi. crappy high 1.5 shorts(no trans brake). definately enough power to run nines. i think p-trim 70 is all you need with a stock block. its all in the tune.