TE-62 to 70GTQ, intercooler, hardware

[GN SBS]

Hi folks,

I'm planning a fairly comprehensive update to my combo from the TE-62 and CAS V4 in my sig and would like your feedback to make sure I'm not missing any details. I'm currently running 10.80s @ 126. I've done a lot of talking and reading and here's what I'm coming up with:

Proposed changes:

* TE-62 to PT70GTQ (.63 exhst housing, h compressor cover) or Turbonetics equivalent
* CAS V4 to Cotton's front mount
* Tial 44m external gate with 1 bar spring
* Sell current 3" THDP with internal gate, 3.5" DP set up for external gate.
* Julio's (Razor) alchy​

A few questions

* I've seen Patrick's recent (very good) post about the true BB turbos. I was not originally considering this, but like the argument about the effect on turbo size. Also Precision's requires water cooling, Turbonetics does not. Any feedback? I'm not going to be using this turbo to its full potential for a good while-- is it just splitting hairs across the two brands assuming I can get a better deal on one vs. the other?

* IF I go BB, will the .63 housing result in a non-streetable combo (blowing the tires away)? I've always liked the TE-62 & .85 housing for reasonable traction on the street.

* Comments on the DP / wastegate setup? I've seen the recent threads and photos on the 70GTQs and 3" DPs and it looks to me like the 3.5" is warranted (or at least a lot of porting on the 3"). Who's making a 3.5" that will actually fit in a car that still has A/C & heater box?

* I've read the good, bad, and ugly IC threads and am less interested in feedback here unless someone has strong evidence that I'd be making a mistake.

*What am I overlooking? Flanges & hardware needed, fittment, other relocations (like the IAC)...
​

Any and all comments welcome. I want to make sure I have all the details sorted out before ordering and all the needed hardware on hand before installing. Hoping this thread will give others lots of good info-- I didn't see a comprehensive thread on this.

Thanks to Jack Cotton and Billy Anderson for helping me do some early brainstorming on this. Both are always willing to patiently lend an ear.

 

[AKplumber]

I have just made the switch from a te-63 ptrim .85 a/r ex. to the 70gtq with a .63 a/r ex. At this point I have no street time on the new combo due to weather so no hard info for you.

I have the same concern about the .63 housing on my 70gtq, I don't believe it will spool as quickly as my te-63 but should be a reasonable compromise between spool speed and top end.

I think the switch to an external gate is a wise move. I've ported my waste gate hole on the new 70gtq but am unsure if it will be an issue or not. With the 63 and a non ported hole it would boost spike pretty badly when the tires broke loose hard. I'm going to give my 3'' thdp a try and see how it performs.

Good luck with the project it should run strong.

 

[RUQWKNF]

Here's my thoughts.

The non ball bearing 70GTQ with a .63 A/R PTE housing will still have a little bit more lag when compared to a TE-62 with a .85 A/R housing. This is mainly due to the 7080H having a larger turbine wheel and larger compressor wheel adding more rotational weight to the rotating assembly. Depending on your converter that you have, it might not be that bad.
Comparing the two PTE 70 turbos to each other is going to be tough until more people start documenting and posting test results and spool up times of the new 7080RH PTE turbo. The real kicker is going to be when guys upgrade their standard journal bearing 7080H (PT70 GT-Q TSM legal turbo) to the new dual ball bearing chra. That info is going to be a real eye opener.

The differences between the two manufacturers turbos are, PTE = dual ball bearing water cooled chra, Tnetics = single ball bearing on compressor side, regular journal bearing on turbine side of the shaft, oil cooled only. If both wheels are identical between the two companies, and they both have the same turbine housing, then the dual ball bearing PTE should spool up faster. But the main difference will be the cost between the two. The other differences between the two, besides the bearing cartridges, is the backing plate, compressor cover and turbine housing. In this instance, it has been proven that the PTE comp cover will flow more air and be slightly more efficient at higher boost levels than the Tnetics cover. (Cooler charge temps) The real decision should come down to this one question.

What will the converter requirements be on the new 7080RH turbo as compared to the Tnetics 70 single bb turbo?


For me, if it was 400-500 rpms lower for the PTE turbo, that would be worth the cost. Because this all equates to less drive train loss. But if the difference were 200, then it would be much harder for me to cough up the extra dough. In this example we're talking about going from a 4000 flash stall converter to a 3500 flash stall converter for a 231 ci combo.

The Cotton FM is fine and has proven itself to be a solid performing FM IC at this power level. No issues there.

The Tial 44mm wastegate would be a good choice if you want to run low boost and high boost. (14psi - 30psi) At this time, I don't know of anyone that has an external wastegate 3.5" downpipe for use with a Tial 44mm on the shelf. Not yet that is.

I was able to control my boost on a PT74 GTQ on my 274CI motor from a low of 17psi, all the way up to 34psi. It had a .85 A/R PTE housing that had the wg hole ported out to the same internal diameter as the external wastegate dp's piping that I was running. I had a single Tial 38mm wg with a 14# spring and a manual boost control knob mounted inside the car.

Porting the hole in the housing and using a standard 3" THDP with a heavy duty wastegate actuator should give you steady boost control. But it is highly recommended to port the downpipe flange to match the turbine housings' turbine wheel discharge hole.
The 44mm will give you a lot more control over your boost level with your current combo.
Hope some of this helps a little.

Patrick

 

[GN SBS]

Patrick,

Thanks for the feedback and framing of the issue-- helpful as always. I'd read your pasts posts on the subject and they've been a big help. A few additional questions based on your feedback. Others please chime in!

* If I go BB, either with the 7080H or turbonetics, what would you use for an exhaust housing-- still the .63?

* How proven is the water cooled setups on TBs? I've applied the standard number of grains of salt, but I've seen some reputable vendors expressing some hesitation about recommending/selling these until they are tested a bit more.

* Unless anyone can raise a strong argument, I'm leading toward the Tnetics BB 70-- I'm not trying to win or compete in TSM and I'm a bit wary about getting too far out on the leading edge.

*Who is making or selling 3.5" DPs these days?​

Again, thanks to all.

Scott

 

[turbojimmy]

Unless anyone can raise a strong argument, I'm leading toward the Tnetics BB 70-- I'm not trying to win or compete in TSM and I'm a bit wary about getting too far out on the leading edge.

I just replaced my PT-61 with a used Turbonetics BB 70 that has a .85 Precision housing installed. It spools incredibly fast compared to the PT-61 it replaced. I have a 3500 Vigilante converter which I now think might be too much converter.

I ported the wastegate hole on the BB70 to match the puck on my 3" THDP. With an HD actuator boost control is rock solid from 18#s up to block-splitting PSI.

The only downside that I've noticed is that the BB70 moves so much more air that I now get a very noticable stumble when coming off the throttle lightly (I have an RJC FMIC that adds quite a bit of volume to the intake tract which may contribute to this - I dunno). I posted about it here and the advice was to put the MAF in the up-pipe, which I plan to do this weekend.

Good luck with your decision.

Jim

 

[pacecarta]

putting the 3" maf in the up pipe has worked for me, but after installing alky i had to move it to the outlet of the frontmount so it doesnt get sprayed with alky when lifting

 

[TOMS86GN]

not on topic but do you have plans on selling your te62? If so im interested

 

[pacecarta]

not on topic but do you have plans on selling your te62? If so im interested

Gauging interest: TE-62 and CAS V4 for sale - TurboBuicks.com