Pretty soon you’ll have to try and post a video up here!

 

Just catching up. Progress:

• Welded up both sides of the exhaust, from turbo to rear bumper. 3.0" out of each turbo till just past the flexplate, then 2.5" the rest of the way, over the differential and to the standard Borla twin outlet tips. There's no mufflers on it, just straight pipe all the way back. It's not loud but I can't say I really like the exhaust note. I'll wait till she's out of the road to assess whether I'll put some mufflers (probably the shortest/smallest housing 2.5" in/out Borla XR1's) on it.
• Didn't like the overly long oil feed lines. Talked to Tiago, he pointed me to a coil of -3an steel braided line and some reusable -3an fittings. Cut the lines to fit, a 'Tee' in the middle of the radiator support and then the line to the oil filter feed point. Much more tidy.
• I've started it a few times and let her get up to temperature, getting the air out of the cooling system.
• Had to relocate the trans cooler. Working on fabricating a bracket for that. Trying to get it to cooler air. My tranny fluid in from the JY 4L80E looks a bit dark, but that may be from the fluid residue still in it when I bought it. I'll flush it out, put some new fluid in it. I have to pull it down a bit to take out the stock TC and install my new PTC TC anyway.

 

Glad to see your back at man and sounds like soon you will be driving it. My old LT1 setup I had SLP Loud Mouth 1 on it with blower, mild work, mid lengths, ypipe, off road pipe and it sounds awesome nice and loud. I’m going to use it on my new build.

 

My understanding with dual turbos and dual outlets with no mufflers is they sound like dump trucks lol. Any way you can ad an Xpipe to help smooth out the tone? Also like your stated even a short perf core straight through muffler or even a resonator of some kind will help. I had true dual 3" on a BBF in my firebird and I added and Xpipe and it really helped smooth out the tone (this was an NA motor and not turbo) but I expect it to react the same. Sounded kinda choppy without some form of balance pipe. H pipes can be easier to Fab and install but Xpipes are smoother to me and offer more power benefits.

Any reason for the 3an lines vs 4an? I was under the impression that -4an feed with open (non restricted pressure fitting) for JB turbos and only use restrictor on BB. I would have thought a -4an feed and then Tee -4an to each turbo?

 

Exactly! Lol... I welded it all up, secured it with some hangers to insulate/suspend the piping, made sure the Borla tips were squared up, connected the battery, fired her up and walked out back with my camera to video what I was sure was going to be a nice exhaust note. But like you said,.... .<Dave's thought balloon> wtf.... sounds like a dump truck.

I'll have time to play around with the pipes to see about either/both the Borlas and X-pipe. Thanks for the input!

 

On the -3an vs -4an oil feeds, I'd used -3an on the prior JB PT7675 so I just left it at that.

 

Thanks! It's been fun and all the welding, alternately on Aluminum, Stainless and Mild steel has made a better welder out of me, that's for sure. Learned a whole lotta "that is the WRONG way to do that", lol.

If we all get to drive our respective cars this year (I sure hope this insanity is over soon and all of us remaining healthy), I might switch to something else next year. Not sure what. A single BW T6 S475 or , if I'm happy with this twin setup, two BW S366. I love working on the car in the winter. I think I'd go out of my mind with nothing to work on.

 

Hey, can I ask why you went 3” to 2.5” for the exhaust? I have twin eBay gt35s on my 5.3 and it’s getting exhaust done now. I have 3” until after firewall then tapers up to 3.5” with resonators on each side and x pipe. No mufflers for now to see how it sounds.

i wasn’t sure about going to 3.5” on each pipe but was told without cutouts I’ll be losing bunch of power so this was the happy medium I guess. However, you went smaller. Hoping mine doesn’t sound like truck with the resonators and xpipe but we will see. Are you nervous of power loss with smaller exhaust?

 

Hi, I went to 2.5" merely for packaging in the tight confines. Awhile back, during the first Turbo adventure(then a TC76 on the front drivers side) the down pipe went under my floor board. That 'reinforcment' rib that goes from left to right made the pipe hang down too low and it would scrape in certain circumstances. I wanted to avoid that experience again so I just put both down pipes going along the passenger side where the cavity GM provided for the stock catalytic converter gives plenty of room. So I route both 3.0" down pipes over the passengers side of the BMR Turbo K member, high up near the passenger truck manifold (which is 'flipped', arching up) then down to just clear the area where the the firewall transitions to the floor pan. At that point, I have two 3.0" Vbands to connect to a short section of 3.0" pipe. After that, the transitions are in place to go from 3 to 2.5". From there, both pipes closely parallel the driveshaft, back to just short of the 8.8 differential. This allows both pipes to use some of the driveshaft tunnel and keep my ground clearance at it's maximum. The car has been in the air on giant jackstands this whole winter , I can't say with authority that the pipes are completely tucked up where they need to be, but looking across the bottom of the car when I place my head in that visual position, they appear to be.

I would love to run bigger pipes but these seem to be a decent compromise. The car has had plenty of 'street power' in the past incarnations, spinning the M/T 315 drag radials with ease, so if it's less than maximal in power in this configuration, I'm sure it will still be a handful.

Do you have a build thread on yours? There hasn't been a ton of reports where F-body guys are using these GT35's. I've had these for so long but getting time to work on it has been piecemeal and sporadic each winter. I'm looking forward to the time when someone can ask, "How do twin GT35's perform?" and I can provide my input.


Hope you all are staying safe and healthy.

 

Hey mine is in a Nissan 300zx. I do have a thread in the conversions section but haven’t updated it in awhile. It seems every time I have something I need done it takes over a month. This exhaust has been over a month now. I still need to cut the IC pipes to angle my SMICs a little more for bumper fitment and my hot side vband leaks.

if we weren’t suffering from corona lockdown then I would be pissed with all the time it’s been taking. However no one else is driving their cars around so I guess it’s whatever lol.

 

Yes. It's rather dead around here too, although.... I did see a small car gathering at the local Harbor Freight. A supercharged 2011 SS convertible, a big Cadillac hearse with a 6-71 Weiand Roots blower sticking out of the hood, a beautiful 69 Z28, a 70 Nova, a 67 Merc Cougar, a ZL1 and several other cars. As I pulled away from the lot, I saw and heard two really loud Mustangs. One was a 2016, the other a 1995 with skinnies on the front, slicks out back and a freakin' drag parachute out back. Lol... Just driving down Central avenue in Albany.

 

Finally got some seat time. Last night, I carefully drove it about a mile from the shop and back, mainly to watch temps, listen for clanging/bad noises and for fluid retention.

1. Rear of exhaust is too low. I'll have to do some reconfig on that.
2. Didn't have the sensor fuse in place, the trans (4l80e) was stuck in 2nd gear the whole time. Fixed that.

Other than that, all was well. Headed back to the house for the night.

Tonight:

1. Went to the local gas station to fill up with 93 oct. Nice that even premium here in the vampire state (NY) is below 2.50 a gallon!
2. On the way back towards the house, I waited till the road was deserted, put her in 1st, floored it while watching the boost and wide bands(HP tuner scanner was running too). Hit 15 psi , lit up the tires(M/T Drag radials 315x35x17) then fell flat on it's face. I thought to myself, "freaking coupler popped off". Headed back to the shop, pulled up and cut her off. Looked at the scanner log. Hmmm.. ran a tad lean at peak boost and got some knock retard. Did a quick coupler check for the ones that are visible w/o getting under the car. All looked well, but I would swear it acted like it popped one. I reset the fueling VE in the areas that were lean, took her for another sprint. Yuck, no boost at all. There's DEFINITELY a coupler off. Went back to the shop and put her on the ramps. Got on my creeper and checked the drivers side plumbing. All good! Rolled over to the passenger side. Aha! What? Looks like I didn't bead roll that thing. Son of a gun.. So ,pulled it off, bead rolled it, re-installed it and went out for another run.
3. The wastegates have 10psi(Correction: found I had the 14.5 springs in each) springs and I don't have my boost controller integrated into the plumbing yet. She only went to 9 psi but the run felt 'good', just not impressive. I'm not sure why it got to 15 psi earlier. Maybe because that was the first time they ever opened? Dunno.
4. Pulling back up to the shop, I cut off the engine, pulled up the HPTuners log and inspected things. No knock retard, running a tad rich now. First 'positive' pressure in the manifold from the twins was 2,500 RPM. Pulled up one of my scans on the Boost controlled PT7675 and it didn't see positive manifold pressure till 3,377 RPM and that was just barely measurable. The PT7675 didn't make even 1psi till 3,480 RPM. The twins already had 1PSI by 3,100RPM.

In the coming days, I'll install the boost controller, reconfig the rear of the exhaust. The exhaust note is not 'too' bad. Still might opt for two Borla XR1's to see if that improves the tone. At least, I'm driving her!

 

Since you fixed the pipe what do you think is wrong?
Be safe out there news said NY is hurting pretty bad.

 

Wrong? You mean about only getting 9 psi? I'm pretty sure that's because I don't have a boost controller to get it up to 21psi like I had with the PT7675. I'll have the controller on it by Saturday and I'll know for sure

 

Ohhh okay haha. I’m coming from supercharger world so never had a turbo. Learning from you and others and I will be sticking to a single when my time comes.

 

Learned a valuable lesson today.
Just because you pop a coupler and find it, don't assume that was the only one...
So two days ago, I posted that I'd taken the first meaningful test drive and it got to 15psi, then popped a coupler. I went back to the shop, re-coupled it, then drove it again, getting into boost but it only made 9'ish PSI.

Fast forward to today. I'd hooked up my Turbosmart Boost-Tee Manual controller yesterday (rained all day ) so I wanted to do some more testing today. Backed the car out of the shop, letting it idle while I got out and checked the trans fluid. Lifted the hood and quickly noticed that sound we're all familiar with, a vacuum leak. WTF? What's leaking? I got up around the throttle body and checked the usual villains, the two ports on either side of the TB. Nope. Where is it coming from ? So I'm moving my head from once side to the other trying to 'hear' the loudest source. Then I put my hands around the coupler to the throttle body to see if I can feel air turbulence. That's when I notice, the TB coupler is 'just' sitting on the opening of the TB. Son of a gun. So I kill the engine, get my 3/8" cordless impact driver and sockets, loosen the Tbolt, reseat the coupler and REALLY tighten it down.

After that, fired up my HPTuners and started the car. No more whistling, good. Took her for a drive, letting her warm up completely. Found a deserted straight stretch , slowed to a stop, put her in 1st, checked traffic again, all good, then applied the gas pedal, somewhat aggressively but not close to WOT.
Holy ****.... The boost gauge shot up to 15 psi as the rear end of the car was all over the place. I let off and let it shift up to 4th as I started shaking. Lol....

Pulled over to check the O2 readings and everything looked good. I also turned the boost controller OFF completely. Eased back on the highway and after another traffic check. Tried it again. Mind you, I'm not going above 67% throttle position on this. I'm watching the boost gauge to monitor boost and let off if things get crazy. This time, I let it get into 2nd gear. So it shot to 20psi at just 50% Throttle position as the 315 M/T Drag radials are spinning, and going from one side of my lane to another and the popped off another coupler.

I smiled a huge smile as I drove back to the shop. I recoupled that popped coupler and put the car to bed for today. So freakin' happy right now. I'm going to have to put some lighter springs in the Waste gates. Right now, they both have 10# springs(Correction: turns out each wastegate had the 14.5# springs).

 

Well, put in the 8# springs and Took her for a test drive/scan. *Better* but she still goes to 21 psi in first. I had to do some recovery driving as the rear end came around substantially. It's going to take some seat time to get accustomed to this

 

Congrats man great news for you! That must have be so much felt to drive it and get the boost up. How does it sound?

 

You know, the sound doesn't bother me as much now for some reason. For sure, it doesn't sound 'racy' or 'sexy', but it really performs well and isn't too loud.

Back in the late 90's, when I'd go to the track and (initially) see those Buick Grand Nationals at the Baytown Texas track, I'd scoff at the exhaust note and my thought balloon was something like "a freakin' six cylinder. Listen to that lame exhaust note". But then my jaw would drop when they got to the end of the track and I'd see the ET's and MPH. I think I have to get used to the idea that while my car won't sound amazing, it will run that way

My first set of DR's when I went to the 11" ZR1 replica rims were Nitto's NR555's. They were better than street tires, but I could spin them with ease. After I wore them out, I went to the current M/T Drag radials, 315x35x17". They hooked better, but they still spun at the track. But at the last years inspection, the inspector barely let me pass with them. I just ordered some new 315x35x17" Nitto NT05R's.

If I (we) get lucky, things will start to go back to normal/new normal, and we can go to the track. I have a set of 'fats and skinnies' that have never been to the track. I really hope to get to use them. I got my TH350 completely refreshed too so I can always put that back in for track work. Gotta say, I'm really impressed with what this bone stock junkyard 4L80E has put up with so far.

 

I know what you mean with the Buick’s but the turbo sounded like a freight train! As long as your happy it’s all good. I just now my hp goal and want the exhaust note aggressive again. Eventually I want 315’s as well just because it looks awesome haha. 275-40-17 looks small now days haha. My favorite rims I use to have were from SLP I had ordered chrome SS rims and after a few months they started to tarnish so SLP worked with me and cut me a deal on 4 new chrome ten spokes which I fell in love with. Unfortunately they started to do the same in the corners and neither rims saw rain. So want to have some ten spoke 315’s made. Or the 17” corvette centennial rims!