zx turbo exhaust Flange

[magnum44]

Alright guys, I have been here for days if not weeks looking at all the possible Flange tags I can find. I am exhausted at this time, I have looked and looked and don't seem to find my immediate answer to my question. I found a kinda blueprint someone posted here with an exact drawing with measurements and everything of the factory flange. I had one custom made in Alabama and when it arrived it  was not what I was expecting, the bolt size are correct but the exhaust opening is bearly over 2" round. Now , My question is, ( after me mocking a 3" pipe to the flange I received) How in the world do I get a flange made with A true 3'' exhaust hole without impeading into the stud holes? I have read here some people saying  that they had a flange made to match a 3'' down pipe? I really don't see how....I would really appreciate someone steering me in the right direction.....thanks, Rob

[aarang]

2.5" is about the most you can get with the stock turbo outlet flange in my opinion. I think most people go from 2.5 into a 3" pipe. I am using 2.5" mandrel tubing with the flange cut from a stock downpipe. If I made the hole any bigger, it would have gotten too thin on the mating surface side. It's pretty slim as is.

[magnum44]

I was mocking up my 3" down pipe to the flange I had made, and I have to agree with you 2.5" is probably the max you can go . I am just curious why I have read some people here saying "yeah I got A 3" down pipe with flange" But I really don't see how in the world you can get such A bore without interfering with the bolts ....So, I guess Im going to just cut my original down pipe flange off and tapper it as much as possible to maximum volume out of it.... I was really hoping to have been able to get a 3" bore because I'm going all mandrel 3" exhaust , but I guess this will have to do....Any other with a better idea would like to hear from you...thanks , Rob

[Tony D]

JeffP did his by taper-milling the turbo to match the exit (which, yeah, is only about 2.5") and then continuing the internal taper to a relatively short, somewhat conical adapter than had a 3" V-Band Clamping flange on it. From there  down it was all 3" mandrel bends. I want to say it only came out maybe (MAYBE) 1/2" or so before the 3" V-Band Flange was on ther.

[magnum44]

Thanks Tony, that's exactly what I have been brainstorming that I want to go with...I will post pics once I get it done..thanks again, Rob

[Tony D]

Check out his photos on Anglefire -- "Extreme 280ZXT" that should give you some ideas.

[magnum44]

Will do, Im on the last nut trying to remove it from the turbo, (of coarse the other 3 came out fairly easy but not this little bugger) 'Ive heated it, penetrating spray overnight still cant bust it loose. and its not rusted either. Got my 3" down pipe mocked up with the reducer going from 2.5 to the 3" down pipe ready for welding just need to taper the 2.25 hole on the flange I had custome made to the 2.5 I need. then I should be good. Im ordering that 3" mandrel bent complete exhaust from  xracing on ebay that goes from down pipe all the way back to muffler all stainless steel polished. but, Im gonna cut out the "Fart can muffler ) it comes with and installing a Megan 3" in with dual 3.5 out pipes. gonna look sick.