When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Going for twin GT35's. Hoping to use two stock passenger side manifolds...
I'll have preliminary pictures up as I make progress. I have test/trial fitted the passenger side and it seems viable so far. The manifold is upside down from it's normal orientation. I will weld a length of schedule 40 pipe to the end of it and that will extend to the T3 flange.
The drivers side will also be using a 2nd passenger side stock manifold, but facing forward. I have not trial fitted this side but it looks doable so far.
So, visually, if you were to raise the hood and look at the engine, the passenger side exits 'high' and the drivers side exits 'low'.
I'll be moving the battery to the rear hatch area.
I'm still keeping the PT7675 on it till I get all the various pieces together. I'm hoping to get out to the track a few more times this season.
Right now, I'm in the middle of converting the Radiator to the standup Griffin. I'm almost done with that. Got the support cut away and the radiator fits fine. Just trying to come up with the best mounting position of the Derale fans so their not appended directly onto the radiator. I've used those 'zip tie' type fasteners that go thru the core of the radiator on a prior incarnation years ago and it ended up ripping a hole in the radiator. I'm experimenting with bolting the fans housings directly to the support metal. Have you been out to the track this year? I've been a total of 3 times so far.
Yes, I have had those "through the fins" ties destroy a radiator before too. Still a couple great track days coming up and this is the best time of the year for making POWA! Lol
I went a couple times so far but I have been chasing gremlins all year. (Not the AMC type) First the injectors plugged up over the winter from the E85, then I had a couple of burnt plug wires, Then I had an issue breaking fan blades when I used my bump box and finally I burnt up my torque converter. I hope I finally have it out figured out. I am hoping to get to the track this Wed. with the new PTC converter. Wanting to get dialed in before Doc's next event on Sept. 22nd.
Excellent! What twins did you go with?
I used to live in Houston(1986 - 2004).
I hope you're okay after Harvey. A good friend of mine has a C6 in Florida. He just sent me a picture of the water at the sills and rising
NICE! I like the thought of the 4" down pipe. With my street setup, I probably couldn't take advantage of that but for race days, I could probably fabricate something that would allow me to use the 4" and dump to the front side.
Maybe I could come up with a 4" for under the car that I could ovalize or rectangulate to keep ground clearance.
Well, apparently schedule 40 piping and fittings is not too common. Nobody local has it. I found one place online that appeared to have decent per-item prices but when I was about to finalize it, it said the shipping/handling for 2 ft of pipe and two EL's was almost $50. I declined that. I did find another place other places online and ordered there but the shipping/handling still is discouraging.
I stopped by a water well drilling shop, hoping they had some 2.5" scrap schedule 40 pipe and some weld EL's but they acted like 2.5" was something they'd never heard of.
At any rate, it's ordered and will be here on around the 19th.
I didn't have the 2nd passenger side manifold and put out some posts saying I was looking for one. A gent I talk to infrequently popped up and said he had some and I could just have them as he was cleaning out his garage. I thanked him and asked when I could pick them up. He replied that he'd text me over the weekend. Weekend came and went, no text. So, I contacted him this past Monday and asked again. He said he'd take them to his work place and then call/text me and I could pick them up. ... No call, no text... sigh. So, I just found a set on 4.8/5.3 manifolds for $24 on ebay and ordered them.
I've been placing the GT35's in the general positions and in various orientations trying to see the benefits of each. I saw Tiago's Twin TC76 T/A a few year's ago in Sugarland, TX and really liked the symmetry he attained with his setup. But I also like the orientation of pointing the downpipe exit straight back towards the back of the car. The only thing that's difficult on that is that there's no room for the air filter on the turbo housing itself. I can always just put a couple of those 'cobra' rubber 90's on the turbos to handle that I suppose. With the Tiago type orientation, I can keep the 7" air filters on the turbos and in somewhat cool(er) air.
Really looking forward to working on all this in the coming months.
I'm not sure if it's really an 'apples to apples' comparison but the twin T3 flange openings comprise an aperture that is incrementally larger than a single T6 flange. So I'll have the benefit of a T6 opening, twice the air filter area I currently have with the same filter(7" K&N type) on my current PT7675 and twin 3" down pipes instead of the current single 3".
Another 'plus' I will try to engineer in the layout is that while I have twin Gt35's, I will also have a T4 PT7675 (the one that's currently on the car) and a T4 On3 78mm(brand new in a box) so I can have those as twins as well. Just putting T3 to a T4 adaptor plates on the hotside.
Last edited by mightyquickz28; 09-14-2017 at 01:07 PM.
Excellent! What twins did you go with?
I used to live in Houston(1986 - 2004).
I hope you're okay after Harvey. A good friend of mine has a C6 in Florida. He just sent me a picture of the water at the sills and rising
Weren't you out towards Dripping Springs for at least part of that time?
Lol sure was! Raced at SAR frequently. I lived in Dripping Springs for one year(2000). We bought some land (22 acres at the Hurlbutt estate) Sold it though after my divorce in 2004. Some great people in the Austin F-body club. Geo, Turtle, Jason Fry, Micah, etc.
Last edited by mightyquickz28; 12-08-2018 at 08:09 AM.
Lol sure was! Raced at SAR frequently. I lived in Dripping Springs for one year(2000). We bought some land (22 acres at the Hurlbutt estate. Sold it though after my divorce in 2004. Some great people in the Austin F-body club. Geo, Turtle, Jason Fry, Micah, etc.
And then there's me, who borrowed/stole your fuel pressure gauge Still need to get that back to you.
Finished getting my 'stand up' Griffin radiator and dual Derale fans set up in preparation for the twins install. Started it up and let it get up to temp while it was still on the jackstands. Checked underneath for any coolant leaks. Luckily, none appeared.
After it cooled off, I topped off the 50/50 coolant and then brought it up to temp again, and repeated the topping off after it cooled down.
While I was under the car I decided to try the routing of the vacuum/pressure hose from the outlet of the compressor housing to the top port of my wastegate, leaving the bottom port open to atmosphere via a tube. The reason for this was, no matter how I set my manual boost controller or the AEM tru boost, I could never attain more that 17.x psi. When pulling the existing tubing off (I'd bought a length of brand new tubing for this effort) I noticed the existing tubing near the boost controller looked to be in poor shape. I didn't examine it super closely but it made me wonder if it had been leaking and causing the waste gate to perform poorly, bleeding off boost early, etc. I decided to just go ahead with the plan to connect the compressor directly to the top port and not even introduce any sort of boost control in the circuit. I intended to be in an open area of the local highway and, while visually monitoring my pillar pod mounted boost gauge, gradually press the gas and stop if/when boost got to 20 psi or thereabouts.
I took the car down off the jackstands, then backed the car out of "Dave's Speed Shop" (actually a long storage unit about 200 yards from my house) and then drove around the facility a couple times, watching the temp gauge. All was well, so I got out on the road and drove to the lonely highway. After a quick visual survey for other cars, cops, etc, I dropped into 2nd at 35 and started feeding the throttle somewhat aggressively. Wooo Hoo! 19.5 psi popped up with only 85% Throttle position and attained 107mph. I shifted to third, put on the brakes. It not only got to the 19.5 psi but it got there damned quick. Also, the temp gauge stayed in the middle of the first tick mark and the first quarter mark. Pretty happy about that.
I'll reintroduce one of my boost controllers into the circuit and see how it behaves. Maybe that prior hose was compromised and didn't allow the wastegate to perform as it should.
Got my 2.5" intercooler pipe/coupler/t-bolt clamp box on Saturday. I'm still tossing around plans for whether to keep the current OBX 3" in/out intercooler or opt for a twin entry, single exit version for the new setup. The schedule 40 straights, EL's are going to be delivered sometime this week. I'll be starting the mockup on the passenger side in the next week or so.
For what it's worth, i love my twin GT35R setup. Little bit bigger motor than you're planning but it's quick to spool!
Going back I might have opted for the new GT3584RS (67mm) but i cant complain with how mine drives. Only issue I have with it lately is traction under 60mph.
LOL... a marvelous problem to have! Thanks for the feedback. Sometimes I think I need an intervention or something. My car, as it sits with the single PT7675 .96 A/R is almost scary to drive. Blistering acceleration on the street. Power that can only be somewhat safely applied at the track and then, only with serious tires under it. Yet... we accomplish one goal, then stand back and look at our engines, heads on hands pondering.. "what If I put a stronger turbo on it?....."
Just got back from the Post office. The schedule 40 EL's arrived. The straights were thru a different vendor so they haven't arrived as of yet.
A question for you my friend, do you let your twins hang off the manifolds or have you provided some support? I'm thinking with the turbos as far out as they will be that I'm going to put some sort of support apparatus under them.
Mine are hanging off mine. Not too far forward but not close. they're pretty small and the downpipe acts as a support as it's rigidly mounted to the block as well.
Here are some quick photos to show the setup without metal on so you can see the support and spans. Attachment 718985
09-11-2017, 09:33 AM
Going for twin GT35's. Hoping to use two stock passenger side manifolds... 
