71 gtq produces less hp than p trim 70

[norbs]

From what i have seen on this turbo on my car there is "zero "improvement in mph and et, actually slower over my 70 p trim. I think the stock manifolds and heads can only flow so much cfm. Howver i did have some transmission problems, but i can't see it costing that much in hp, as i fixed the tranny and the mph is still low. The converter is too loose but once it locked it should mph the same. I have lost 3 mph conisantly !



gtq71= 10.5@129 #26 1.57 60' tranny brake
gt p trim =10.4@133.5 with less boost #25 1.7 60'


Where is the 100 hp i was supposed to pick up with the gtq?

 

[NEARING]

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[norbs]

yes im shocked also

 

[broke1]

You think it could have anything to do with the fact youre running 4 bolt turbo's??Or maybe something else has changed??Or that a q trim likes even higher boost??

 

[Nick Micale]

Originally posted by norbs
...................... I think the stock manifolds and heads can only flow so much cfm. ....................

Where is the 100 hp i was supposed to pick up with the gtq?

It is sitting there figuring out how to get to work through those stock heads?

 

[86brick]

Norbs, what size DP are you using with the 71gtq (3" or 3.5")?? Also, when you say stock heads do you mean stock valves?

 

[salvageV6]

Norbie didn't you get that Magik Felpro program with yours?

 

[DR BOOST]

i did the same swap as you norbs....the result was 45 more hp with no other changes......but.....the cars spools much slower.

 

[norbs]

The heads do have larger valves and are ported, i should have said iron heads instead of stock. The felpro shows its taking out fuel, which means its making less hp. The dp is 3" though. There has to be a problem with airflow, might change the headers?

 

[86brick]

I don't think the headers are hurting you, but it might be time for a 3.5" DP.... I would be willing to bet that most if not all of the TSM guys running a 70/71 GTQ turbo are you using a 3.5" DP.... With the 70 Ptrim I think the 3" DP works fine, but once you go to a Qtrim turbo the 3" DP seems to be a bit of a bottle neck...

 

[NCTURBOS]

Originally posted by 86brick
I don't think the headers are hurting you, but it might be time for a 3.5" DP.... I would be willing to bet that most if not all of the TSM guys running a 70/71 GTQ turbo are you using a 3.5" DP.... With the 70 Ptrim I think the 3" DP works fine, but once you go to a Qtrim turbo the 3" DP seems to be a bit of a bottle neck...

Sully runs a T-70BB Q-trim with stock headers and a 3" THDP. It went 10-teens @ 132mph+ at Norwalk.

Not to say that a 3.5" won't help. I'm just saying that there are some running a 3" w/ a Q-trim.


K.

 

[chevyII]

Aren't you running a smaller exhaust housing on the Q than most? I thought that I had read in a search about Q trims that you specified a .69 housing instead of a .81? May have been somone else.

 

[norbs]

Actually i have both housings .81 and .68. The .81 is just too mushy for the street, and i never had a chance to switch them at the track, it takes a while to do that when everything is baking hot. I do have atr headers i could try, or change the turbo at the track and do back to back testing.