Wicked69

I currently run twin PTE 62/62's, .58 AR on my stock bottom end 1969 Chevelle. This was my first turbo set up and am happy with the results. However, the 5.3 recently blew up and I have already replaced it. My turbo's were bought less than a year ago and have already been back and rebuilt twice, and now the other turbo has a leaking seal. I like the set up and don't mind redoing the piping etc... Basically don't mind trying new things. Anyways, the local turbo shop knows of my problems and they have a Precision 74 GTQ, SP cover, and .96 AR. They offered to trade them straight out for my twins. I probably have more money into them but am tired of all the problems, mainly it is a bitch to diagnose a problem when one maybe bad, the other works, etc.. I have a chance to also swap out my Vic Jr and elbow for the powder coated Edelbrock Pro Flo Xt.

My question is would this turbo at least be similiar in performance, less in performance or more in performance?

Right now I use Stock bottom end 5.3, with an XER273 cam but could do a cam swap if needed, stock heads with patriot gold valve springs, LS9 head gaskets, E85, meth injection and 20lbs of boost. My car is about 90% street and 10% strip, however, I would rather it not run as well on the street than to give much up at the track. As long as it drives decent on the street I am happy. It has gone a best of 118mph in the 1/8th with this set up in a nearly 4,000lbs Chevelle.

These trades are straight up. Not worried about redoing my hot and cold side. It is the easiest thing I can do. lol especially since I don't run an intercooler.

rotary1307cc

iTrader: (5)

It would be one extreme to the other that is for sure

Think tc76 with not as much turbine or compressor

No where near as much turbo as the twins....

SPRAYED 01

iTrader: (22)

Ya you will be disappointed with just one of those compared to the twins

Wicked69

I am just thinking it may be easier to tune and I am tired of one turbo always having something wrong with it. I think sometimes you just get unlucky with a turbo and I have. Yes the new turbo is precision but he hasn't had any problems with it and it has about 30 passes and only about 1000 street miles. He traded up for a used 76 for his truck. I probably will never go over 25lbs of boost, and more than likely will stay around 20 or less, so figured it was plenty and I could clean up the engine compartment some.

Wicked69

In what sense? street driving, 1/8th mile times, 1/4 mile times? I don't care as much about the street driving if I can still run better at the drag strip.

SPRAYED 01

iTrader: (22)

I think all of the above. Its a pretty small turbo to run as a single. If you want to run a single a gts 76 would be awesome.

Wicked69

I figured a 76 would be the minimun but for a straight up trade I figured it would still work pretty well. I am only going to run a 4.8/5.3/6.0 depending what I get my hands on. Most times a 5.3 with stock heads. I figured that would be about the right size turbo or at least close with the small cubes and stock heads.....NO?

rotary1307cc

iTrader: (5)

Its not the 74 that is the problem it is the Q trim turbine....... you are talking about going from two 62mm turbines to one 68mm......

Keep the twins. No reason to be having turbo problems over and over. You have to have an issue with oiling, draining, crankcase pressure, ect to be eating turbos

Figure out the problem and be much better off

Wicked69

I thought it has a 75mm turbine.....

black98ws6ta

iTrader: (77)

Not the q trim...I dont think.

Wicked69

Is the GTQ different that the standard Q trim? I thought it was.

Wicked69

Also it states it supports 1060 hp. I am only trying to be around 700rwhp. That is about where I was at with the twins set up. Surely that it enough turbo using E85 and meth?

Wicked69

Here is the link on it....am I not reading it correctly. It looks like a 75 or 81mm wheel are the options. I don't see anywhere it shows a 68.

http://www.precisionturbo.net/produc...ger---7475/276

rotary1307cc

iTrader: (5)

That is a gts (S trim turbine)

If the gtq is different than the standard q I would say that it is just the blade design on the wheel. I would think it still retains the ~68mm turbine exducer

SPRAYED 01

iTrader: (22)

Measure the turbine. If its a 68mm then I wouldn't do it. Its kind of seems you are set on making this a single. Why not sell your twins to them, throw in a little more cash and get a real nice new single turbo.

DrTurbo

iTrader: (3)

Gtq is much smaller then the gts. Big difference.

SStolen

iTrader: (22)

You went 118mph in the 1/8th in a 4000lb chevelle with only 700rwhp?

a4ls2goat

I'm sure that thing was well over 700whp.

Keep your setup man, that thing is pretty nasty.

What size feed/ return do you have? Any pics of it.

Wicked69

No. I want to keep the twins but I am just tired of havieng to redo this damn turbo. No matter what I am being told over and over, I am not doing something correctly, yet the same turbo keeps screwing up, no matter what I do.

I have a -6 feed going to each turbo off a -6 Y fitting. Plenty of oil. I was told -4 was not enough and that was why it went out the first time. Did the -6 and it went out again. This time it is just leaking on the seal but still, new turbo under warranty and still forked out $500 for a rebuild, the next one they covered but don't feel like messing with it again.

I have -10 Drain lines below the turbo in a direct line to the front of the oil pan. Doesn't seem to be any restrictions but personally I think the damn -6's are feeding it more oil than it can drain. Not sure why the other turbo holds together. Even tried swapping sides.

As far as horsepower. I am not sure, just trying to make an educated guess without being one these guys throwing out the number 1000! lol The only dyno was when we first tuned and it made 588 to the wheels but on that tune it only ran 6.83 at 100mph.

Here are some pics:

a4ls2goat

You were making something closer to 800whp.