iroc90dfi

I have a 1990 IROC with Hooker Super Comps with true dual exhaust. I would like to keep my headers but change to a single exhaust muffler setup (similar to the the factory style exit). I tried using the Mufflex Y-Pipe Product Number TPIY-02 but this Y-Pipe will not wok with the UMI 700R4 Crossmember Tunnel Mounted Torque Arm Mount w/ Loop as the Y-Pipe hits the crossmember and will not connect to the headers. I need some ideas on information on what components I can try to make my own Y-Pipe.

The setup I am looking to do is connect my long tubes to a Y-Pipe that I can connect to Mufflex 3.5" inch Exhaust Pipe with a Magnaflow Muffler into a single Hideaway Tailpipe system PN 82352CM. See attached picture of what I would like the setup to look like

Anyone have a setup like this or similar that can provide from feedback or advice

Thank you

exiled350

iTrader: (1)

The UMI crossmember sucks, I had one and could not find a way to get long tube headers to work with it. The Holley Blackheart crossmember will work with a 700R4 if you use the 4l60e bracket and the adjustable trans mount summit sells. I have the full blackheart exhaust and, while the headers are trash for as much as they were, the rest of it fits beautifully. If that system was designed to work with a stock, stamped steel crossmember I would think the Holley mount would only give more clearance.

IROCZman15

iTrader: (25)

I have/built the y-pipe you speak of. I have a bunch of photos of it, but I basically built it with a tig welder and sections of pipe that I pie-cut and contoured. It was a heck of a project, but it was my best option, because I wanted to ensure I got it completely right and an off-the-shelf-kit was not going to check all the boxes that I needed it too. I cut out a section of the factory frame but reinforced it differently. I welded on the v-bands because those usual 3-bolt triangle header flanges were bound to leak and that would cause all sorts of havoc with my oxygen sensor inches away, so the v-bands are the best for a near-perfect seal. I also used a small length of flex pipe on each sized of the y-pipe because the motor torques a lot and I don't want the whole exhaust system to be too rigid and tear itself apart. While I don't have the exact same headers that you do, mine are 1 3/4 primary with a 3" collector diameter. As for my trans-cross-member, well thats not an off the shelf piece either; I ended up making it myself to gain clearance for the y-pipe tubes. The black actual 3"-to-4" merge pipe is an off the shelf flowmaster part, but I cut length off of it.
-If you are only interested in off-the-shelf kinda bolt-in parts, you might not have luck finding a lot of options, without sacrificing something in the areas of ground clearance, other components clearance, price, etc.So, if you can fabricate stuff or know a friend with welding skills, you might have some more options.

ughmas

As far as off the shelf, there is not much out there for y-pipes as iroczman15 noted - since you said you are looking to make one yourself, all you really need is the tubing and the ability to cut and weld it how you want. They also sell premade pie cuts and builders kits with mandrel bent tubing to make it easier to fabricate if you dont have a good cold saw setup.

iroc90dfi

@exiled350 thanks for the reply, yeah I probably could switch over to the Blackheart crossmember and think It will work with the Muffelex Y-Pipe but not sure if the UMI torque arm will work.

iroc90dfi

@IROCZman15 thanks for the write up and pictures, this is awesome and what I am looking to do. The black Y connection is that a Flowmaster piece? what is the rest of exhaust? 3" or 4"?

iroc90dfi

Here is a setup the Fireball Camaro did but he is running the stock torque arm and not sure how much difference it makes using the aftermarket one with clearance. I think I will just get some pieces and try to see what I can fab up.

,

IROCZman15

iTrader: (25)

yes, its a flowmaster Y300400 piece:
https://www.summitracing.com/parts/f...xoCP4cQAvD_BwE

The rest of my exhaust is the 4" mufflex system with a magnaflow muffler and a 4" single exit turndown exit. I did some work on some of the pipes too, but the mufflex kit is a really nice system

exiled350

iTrader: (1)

The blackheart mount requires a stock style torque arm. If you have the UMI one that has a poly bushing on the end that mounts with a pair of plates, it will not work. I had to get the stock replacement style one that has a tubular nub at the end and matching bushing.

skinny z

I bought a couple of Vibrant U-J bends an fabbed a Y-pipe that connected my Hedman headers to a Flowmaster cat-back exhaust system.















The 2 into 1 merge is a Magnaflow part.
The OEM crossmember was notched and reinforced to suit.

skinny z

Another option Zman is to weld the 3-bolt flange to the headers and mate that to a similarly welded flange on the y-pipe.
When done correctly and using Remflex gaskets, it's been installed and removed more times than I care to count and has never leaked.





There's a narrow bead tigged onto the face of each flange.

That said, my resources for reproducing this are all but gone. The idea of using a flexible piece between pipes as you've done gives me an idea of what I can do with what I have at my disposal now.

TTOP350

iTrader: (8)

Don't mind my temporary 25yr old Ypipe. (Redoing it in stainless right now)
1st, cut off the headers worthless 3bolt flanges
2nd, get slip fit 3" pipe and the flat band clamps, 4x 45deg 3" bends and fit it all together and weld away.
3rd, section the framerails and move them as tight to the floor pan as you can
4th, cut , section and weld factory crossmember to bend back up to framerails. Be mindfull of drive line angles.
​​​5th, scrap angle iron and muffler hanger with rubber in it and make a hanger to one of the nuts for tq arm on the trans.
​​6th, band clamp to catback
7, enjoy your super easy to remove Ypipe.

This is all 3" pipe and has ground clearance that rivals a 4x4 (not really but it was funny in my mind)

skinny z

Why?

TTOP350

iTrader: (8)

So dual 3" Y pipe fits easily with good ground clearance.

skinny z

Fair enough. That's what I figured.
I went about it a slightly different way but to each their own. You've got a good looking system nonetheless.
The prospect of cutting up the infrastructure unsettled me somewhat. The crossmember? No problem. We took a slice and dice to that but it's easily replaceable should the need arise.
I may be revisiting this whole deal again in the summer. When your new y-pipe is built, I hope you post up. It might be inspirational.
Aside from wanting to 1) divorce the torque arm mount from the transmission and 2) add appropriately placed cutouts for race days, I haven't figured out how to go about it. There's a long story attached to this but I've a Holley crossmember with big arches for clearance (still in the box) but my current y-pipe won't work. So there's replacing that or build a new crossmember to suit the y-pipe I have. Along with that is the separated TA mount combined with the crossmember. Anyway, that's in the planning stages.

QwkTrip

iTrader: (22)

That nice exhaust system in Post #1 has 3" pipe around the transmission, merging into a 3.5" single. It actually has two different Y-pipes depending whether you have a manual trans or auto trans (wider). The auto trans version kicks out wider to go around the transmission and the pipe is flattened on one side along the passenger side frame rail. No cutting of car.

It requires a double hump trans crossmember of generous proportions - larger than the Hooker Blackheart. Because of this, there is no room for a relocated torque arm. You either have to use stock torque arm on tail shaft of trans, or a shortened torque arm that mounts to subframe connectors.

Member @TEDSgrad has the auto trans version in his car.

skinny z

Seems you LS swap guys get all the toys.
It's a total shame (and a sham if you ask me) that Holley's Blackheart headers for these cars was quashed.
There's some negative feedback on fitment but just the same, it looked to be an excellent jumping off point considering that there was entire exhaust that would attach to them. One which I had anticipated doing until the powers that be said "No way!".

QwkTrip

iTrader: (22)

Stainless Works makes one off custom exhaust for customers. Not everything is on their website. You could call them up and see if they have any exhaust on file for your type of car and headers. They will run it down the production line if they have it. They may not be able to search by features like that though, the data might be tied to customer name.

alan91z28

actually my son and i utilized this stainless works type exhaust with his LS3 swap in his 87 Formula. we had to cut up the y-pipe to make it work, but in the end we got it to work out well with the hooker/holley cross member and utilizing a full length UMI torque arm mounted to it

see post 27
https://www.thirdgen.org/forums/ltx-...-ls3-swap.html

iroc90dfi

Thanks the picture helps

iroc90dfi

thanks for the info, I will look into that

iroc90dfi

Thank the info is really helpful

72buickgs

Ingenuity for all you fellows! Great job guys!

TEDSgrad

iTrader: (4)

Fitting big exhaust down the tunnels takes time and revision. Nothing out of the box will fit - even though that might be how it is sold to you.
I took mine to a couple of guys who built frames/exhaust/suspensions for Bonneville Salt Flat cars. They took the trans bracket and brought the attachment point up above and through the frame rail horizontally. They welded collars that go through the frame rail so that the bolts attach horizontally rather than vertical held by bolt threads. They also slightly scalloped the frame rail for clearance.
In this pic, you can see the two horizontal bolts inside those collars and where they scalloped the frame rail. Of course, after the pic this is covered in POR-15 once again.

2 V-band clamps are not very far below trans pan

Re-sectioned tube to fit

Trans member attachment Pass side up above

Not much below the trans pan

TEDSgrad

iTrader: (4)

I also added some support to the intermediary tube to keep it up off the torque arm cross-bar. I have a 3" aluminum driveshaft, exhaust tube, and

The two clamps and the cross-bar are the lowest points


BMR Trak pak going down that tunnel.