Stock l28et exhaust question

[Leeroy]

Ok so I hav a 73z with a l28et swap and I want to redo the exhaust because the previous owner did a bad weld and cut different pipe sizes and welded the together amd also didnt weld some parts so Theres major exhaust leak. I just purchased a HKS hi-power turbo exhaust with 3inch inlet. The car is only going to be daily driven. Its all stock and is going to be for a while. So which exhaust size would be best? 2.5, 2.75, or 3 inch piping? Im hoping to do the piping in two days so i would appreciate the help as soon as possible. Thanks

[FlatBlack]

Best?

 

3"

 

[Read this about "best:" http://forums.hybridz.org/index.php?app=forums&module=extras&section=boardrules]

 

You need to put a location in your profile as well.

Edited July 7, 2010 by FlatBlack

[Drax240z]

3" or don't bother!

[Leeroy]

Alright cool thanks for the tips and help. Im using my mobile phone righ now so havent had time to put my location. Im from fresno, ca though. I was asking cause this exhaust shop said bigger isnt better, but I didnt agree with him. Thanks again

[jc052685]

3"

[Drax240z]

The better it flows, the better the end result in a turbo application.

[Brad-ManQ45]

Don't go back to that exhaust shop.

 

Or any of them that recommend a Flowmaster for a turbo car either for that matter.

 

If you need to ask why you haven't used the search feature of this forum.

[xShodaimex]

So this will be custom made? Let me know what shop you end up going to for the piping. I would love to see the results!

[stprasinz]

3" come on guys... 4 inch or bigger.... lol. 3" will do wonders... and the turbo itself creates more than enough backpressure for the engine... which I'm not tryinbg to start the age old no back pressure is too much argument either lol.... but realy if they ever make a vacume for the exhaust Ill buy it, cause any back pressure is too much lol....

[goodoldjam]

You need to consider cost, source some premade 4" mandrel bends and open up that wallet. I can get 3" mandrel bends for a decent price. Go Crush bent 4" and you may as well say goodbye to the diameter advantage.

[stprasinz]

I got a deal 3 4" mandrel u bends for 44$!!!! add in some staright pipe, and I amgonna have about 100 total for a full 4 inch mandral the deals are there when you scour and scour and then scour some more.... but thats just the tubing, from there I'll also need a few clamps, and maybe a muffler...... or not lol..

[Zmanco]

...I'll also need a few clamps, and maybe a muffler...... or not lol..

I had a local muffler guy build a 3" for me using mandrel bent U pipes and it turned out well. Initially I had him build it without a muffler, but it really was too loud for me to drive home (I live in a community with very little sense of humor about noise). So I had him throw a glass pack on so i could drive it until I could order a muffler. Turned out I like the sound of the glass pack and it's not too loud or quiet. Hence I've just driven it like that for almost a year now. FYI, this is with a Schneider stage II turbo cam. My past experience is that stock cams are louder so take that into account.

 

And to answer the original question about pipe size, I'd suggest 3" as it's a decent compromise that doesn't add too much more weight, can fit under the car without scraping too much, and gives you the option of going with a bigger turbo later and only needing to modify how the downpipe mates to it. I think you find it's hard to go over speed bumps with anything more than 3" - I just scrape lightly on most around here (springs are Tokico reds).

[letitsnow]

My 3" exhaust sits up higher than or at least about equal with my frame rails, it shouldn't scrape any worse than the stock system. I made it myself out of 2 180° 3" mandrel bends and about 8' of pipe, only took a few hours to do total.