hello everyone, i would like to get some feedback form you if you have some knowledge about it.

recently i have put on 3' exhaust starting from headers on my evo 9. while driving it with new exhaust now, i have noticed that i have a bigger or longer lag then when i used to have. there is just little more hesitation before turbo kicks in.

just to make it more clear, i do not have any other modifications, stock air-filter (K&N).

please advice all help its much appreciated !

 

3 feet is a huge exhaust pipe

Kidding aside, get your car tuned, the factory tune is not optimized for a large free-flowing exhaust system.

 

^^^^this , funny BTW!

Think of it in terms of velocity...smaller pipe more velocity--less volume, larger pipe less velocity more volume at the same rpm as the smaller pipe. Velocity spools the turbo. With all that said--as mentioned above, tuning will compensate for changes.
BTW, dont get in the habit of putting on bolt-ons and leaving the tune till later. You may find that an expensive mistake.

 

Agreed, a tune will help greatly and you will not have the same problem. Just be sure to check for vac/boost leaks and gap your plugs accordingly prior to tuning. I would advise if you could, get a walbro, lower intercooler pipe and a O2 housing in addition. Good luck!

 

Yes I agree a 3 foot exhaust is a little excessive. 3 inch will be fine. You should have faster spool and less lag with that exhaust.

 

Agreed with all. Tune.

 

Get a tune, but before you go for the tune install a manual boost controller and think about a fuel pump. Just try to get something out of the tune

 

Tune and boost controller.

 

lol sorry guys typo about the 3' hahaha i got an 3" and i appreciate your feedback! everyone seems like its saying get a tune.....well not to sound nub but how do i get the "tune"? is it osmething i can do it or would i have to take it to a shop? is there an easy ecu download and reflash? i live in middle of US and closest awd dyno is 3.5 hr away.....please help

 

I experienced the same thing when I installed my 3" turboback exhaust. Get a tune. Or get more bolt ons, then a tune!

 

you mean get more bolts on the exhaust or? and how do i get the tune? thanks!

 

for all the smart people here saying I need a "tune" just stop.....you will need a tune if your car idel is dropping below then usual, if you are runing rich or lean, etc......I finally found out what was my problem and I need a new clutch...so for all of you who experience the problem I have stated here...RPM's jumping and dropping when turbo kicks in, your clutch is slipping and you need a new clutch....cheers!

 

If the exhaust manifold was still stock then changing the exhaust post turbo shouldn't affect spool. Post turbo would affect the amount of boost. I.E. less back pressure and you will boost more. If anything you would experience an overboosting situation which the car would cut boost.

Now a slipping clutch is a completely different story.

 

Here we go.

You do need a tune with a 3" exhaust. You can't argue that point. The fact that you referenced a tune as if it was a magical artifact tells me you haven't done nearly enough research before buying an evo.

You didn't say your RPMs were jumping when you hit boost. You said your turbo was lagging. Those are totally different issues.

Fix your clutch. Get a tune. Learn about your car BEFORE doing anything else to it.

And I mean all that in a nice and helpful way. Not a "you're an idiot" kind of way.

Edit: I just saw the more bolts on the exhaust comment.....you are either 16 or a fairly respectable troll.

 

Your username makes me think this: