Did you guys lose alot of ground clearence? I know 2.5 will be better for clearence but I want the 3". I just can't decide. Is anyone lowered? I don't plan on it but I may change my mind and don't want to scrap everywhere. I don't mind tip toeing over speed bumps but I have to be able to get into my driveway. I need some suggestions. Thanks

 

do a search..i made a post about this maybe a week ago. One guy sent a photo and i think he had a 3 inch set up and was lowered, he could fit a beer can on its side under it and still had a bit of room. ithink his name is fulton1? can't remember

Id say if you are only gonna lower an inch-1 1/4 inchs, i say go for it. anything more, go with 2.5 inch and dont plan to run the exhaust out the back. it all will depend on how you make your x pipe and which mufflers you use. and if you are willing to beat in the floor board of your car.
hope that helped some
Travis

 

Did a search. That's the post I was looking for. Thanks. I remember that being not alot of room. Any speed bump or even the suspension travel, I think, will exceed the width of a beer can and therefore be prone to hitting. I planned on doing a 3" dumped for a while and the put 2.5" extensions over the axle.

 

yeah there isn't much room, but what is your z to you? is it a daily driver? a track bitch? road course? if its a DD, id say stick with 2.5 inch piping. for the most part 2.5 inch mandral bent pipe would be more than enough for your mods. just if you go that route make sure you buy 3"-2.5" reducers for the header collectors...im having a hell of a time fixing a ***** up by a shop for not using those...

Best of luck to you.
Travis

 

It my 3 times a week, I like to cruise, car. If I go 3" i am going to have the the pipe ends expanded to 3" ID to slip fit the headers. If I go 2.5" I will have to buy two 3-2.5 swedged extentions and have the 3" expanded the same way. What happend to your setup?

 

the dumbass that told me he knew how to make true duals for ls1's (he claimed to have done it 15-20 times thus far), obviously smoked too much reefer, he just butted the 2.5 inch pipe against my 3 inch collector and welded the **** out of it till it didnt leak. the pipes were not bent very well and hung down quite low (~2.5 inchs from the floor board) just overall a shitty shitty job, I have now a good shop and the guy is trying his best to fix it...still not looking real good though.

 

Blaster,
IMO, there are three main clearance issues for TD's on a lowered car regardless of pipe diameter:

1) The driver's side just behind the collector (assuming you have LT's) where their's a subframe brace that runs inboard/outboard. This area is a killer if you use cats. If you can go with OR pipe then use one of the Dr.Gas 3" frame clearance tubes. This will make a lot of difference.

2) The X-pipe itself. This is especially true if you're using a DSL. The fact that you have to locate the X to clear the TA and the driveshaft makes placement tricky. This is an area where a good exhaust shop is worth their weight in gold. If you're going to use a DSL, then I would recommend the Lakewood, it seems to allow the most clearance for custom exhaust setups.

3) The mufflers. Bullets are going to be your best bet for small size, but they'll also be the loudest. The Dynomax bullets are 4" overall diameter and even these are a tight fit. Your options here are more limited. Pretty much all you can do is bang in your floorpan or otherwise modify it to clear regular mufflers or tuck bullets up better. Of course trying to get something over the axle will solve this problem, but may create others. If you want dumps and don't want to modify the body, then you're best bet is to get the mufflers as far back as you can. This will reduce their chances of dragging on speed bumps, curbs, etc.

With these points in mind, I don't see a 2.5" system gaining you much clearance. The 2.5" mufflers still have the same overall dimensions as the 3" designs in all cases I've seen, the header collectors are still going to be at the same height, and the use of a frame clearance tube with a 3" setup will allow you to clear the problem on the driver's side better than a 2.5" round pipe would. There are X-pipes out there with a 3" inlet and 2.5" outlet, which may be a compromise - especially if you want to try and go over the axle. Also the BMR upper PHR may help (I've never seen one installed myself, though).

I think if you address the above and have a competent shop build the exhaust on your car then you can get by with 3". You'll obviously have to be more careful than you would with a non-lowered car, but then that's true of any lowered car. About the only other thing I can think of if you had an unlimited budget would be to use some of the trick oval piping that Dr. Gas and some others offer. I wouldn't want to see the bill for that though

HTH

 

That was may rational as well. Thanks for you points. I was going to run the sweet chamber mufflers for the best clearence. I wish I could get some oval piping but the bill is already high because I am doing a stainless setup.

 

http://community.webshots.com/album/132355665TPXbCQ

3" TD on a lowered vert...no drag.

 

I have 3" on my car but with real mufflers and the bottom of my exhaust is scrapped all to hell and Im not lowered. When I had the SLP Eibach springs in the rear, I hit EVERYTHING. I had to raise the rear up to stock height, but I still hit everything. Im going back to a Y and CB so I can lower my car and the sound

 

ive got 3" duals on my 99 TA lowered and it dumps before the axle with flowmaster 50 series mufflers. Sounds better than any car Ive ever heard but ground clearance was about 3/4 inch so I raised the car an inch in the rear and now its perfect.