90mm TB conversion, which couplers?
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
90mm TB conversion, which couplers?
Guys, I ran a search as usual but didn't come up with specific answers to my questions. I'm working on a Intake conversion (FAST or TPIS 90mm) and I've already picked up the LS2 90mm TB. I'm also planning on a larger MAF. My question is which couplers will fit the OD of the LS2 tb as well as the larger MAF. Its possible that the answer is that the OD's are the same with the 85mm MAF and 90mm TB but I'd like to make sure before getting things all ripped apart and having stuff not fit.
I called one of the forum vendors directly regarding my application and they could not verify that EITHER end would fit! I was totally baffled that a vendor wouldn't know if their airbridge coupler would fit a 90mm tb or not.
I called one of the forum vendors directly regarding my application and they could not verify that EITHER end would fit! I was totally baffled that a vendor wouldn't know if their airbridge coupler would fit a 90mm tb or not.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
Sweet, I was going to do this once I had the MAF in my hand but you just saved me a good chunk of time. Except for possibly swapping out the airbridge at a later date, sounds like I'll be able to re-use my stock setup.
thx blownblue!
thx blownblue!
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
I've been there for a while and have done a lot of cutting and fitting to make my setup work. The stock airbridge to throttlebody coupler is a little smaller than the LS2 throttlebody, but you can stretch it a bit to get it on. I went with a Haltech airbridge from a Stinger because it has a 100mm opening at the throttle body and they supply you with a 100mm coupler. It all fits together with the 85mm MAF and oem clamp perfectly. I am using a Vararam so I had to cut about 1.5 inches off the front of the Haltech and notch it to make it fit well to the VaraRam. If you want to go with a larger MAF you'll to experiment more. I don't know of any premade aftermarket airbridges that would be a good fit for 90mm tb and 100mm MAF.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
I have a vararam also, thx for the info Arkay99. I'm planning on no bigger than a 85mm maf (I believe I have a 78mm one now, I need to verify since it was swapped with my vararam and I was told it was the larger one.
My big concern was the TB diameter and it sounds like stock or aftermarket its a non-issue.
Thanks for the data guys!
My big concern was the TB diameter and it sounds like stock or aftermarket its a non-issue.
Thanks for the data guys!
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Pro
Joined: Feb 2003
Posts: 623
Likes: 11
From: Ankeny IA
It won't. You'll need both an airbridge and coupler upgrade to get the full benefit of the 85mm MAF (as well as a tune). The coupler from the airbridge to TB will work.
Last edited by 99C5JA1; Aug 11, 2008 at 04:48 PM.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
I need to check, if the OD of the 85mm is similar to the 78mm, you do NOT need new couplers...that is the basis of my question. I don't have an 85mm on hand to measure.
The jury is still out on the airbridge upgrade....if the couplers on an OEM airbridge fit the upgraded items, then the airbridge itself might not be a restriction.
The jury is still out on the airbridge upgrade....if the couplers on an OEM airbridge fit the upgraded items, then the airbridge itself might not be a restriction.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
Yes, good point, the MAF's changed over in 2000 (or was it 2002) to the 85mm MAF. I guess I could look into a 2000+ oem airbridge (gotta be CHEAP just about anywhere) but I would like a measurement proving that the OD of the 85mm is different than the 78mm. Sounds like 99C5JA1's results support the fact that the MAF end is larger.
Pro
Joined: Feb 2003
Posts: 623
Likes: 11
From: Ankeny IA
The MAF changed in '01. I've been running a descreened '01 MAF since switching to a 90/90 setup. I borrowed an '01 airbridge and ordered a filter->MAF coupler from SLP. The stock airbridge to TB coupler works fine since the outer diameter of the LS2 TB is the same as the LS1 (only the inner bore diameter changes). I'm running a "high flow" airbridge right now, but doubt it's doing much. I mainly changed to get my buddies coupler back to him.
Pro
Joined: Feb 2003
Posts: 623
Likes: 11
From: Ankeny IA
People have went a couple different ways in providing air for the PCV system. The first is to buy a plastic elbow, make a hole, and insert it into the coupler. Some have used the elbow from a Callaway intake and others from a HELP vacuum line from a parts store. The other route is to install a breather/filter onto the line. In my case I used a filter meant to go onto an air line and inserted it into the hose.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
I just measured the TBs and the OD of the LS1 and LS2 tb's are both EXACTLY 101mm.
Arkay, thanks for the pointer on the Vararam...I will be slipping on my 85mm MAF and newer airbridge (I'll pick them up one the forum soon) when I do the intake upgrade.
Thx for the help everyone, sounds like a newer oem airbridge and coupler for an 85mm MAF is the answer for my 90mm upgrade!
Arkay, thanks for the pointer on the Vararam...I will be slipping on my 85mm MAF and newer airbridge (I'll pick them up one the forum soon) when I do the intake upgrade.
Thx for the help everyone, sounds like a newer oem airbridge and coupler for an 85mm MAF is the answer for my 90mm upgrade!
