I bought a built evo8 a couple weeks back. I love the car except for the exhuast. Even though it's quiet compared to many other 3" exhausts, it's still way too loud for highway driving (where I spend a majority of my time). I'm looking for a cat back that is no louder than stock (even the rre stealth is too loud for me). Since fujitsubo is no longer produced, I've decided to just go back to stock.

Two questions: how much of a loss? The car is currently around 470whp. It has (among other things):
HKS 280 cams
Borg warner 59mm turbo
3" dp and HFC

The car is going to be tuned next week. Is it safe to drive on the stock exhaust until it gets tuned?

Thanks for the info.

 

I know how you feel. I have the stock cat back exhaust with a 3" dp that leads to a boost actuated cutout that fully opens at 10psi. Going from the 3" TBE to the stock CBE I lost quite a bit of hp. Going to the cutout I gained more than the 3" TBE.

However, it's really loud when it opens. I have the Sound Performance cutout, but I'm not happy with it becaue it leaks exhaust at idle/cruise. In the near future I'll be designing one that doesn't leak at idle/cruise. GL

 

Im in the same boat. I do a lot of highway driving and my exhausy is just getting a little annoying. Especially after a 12 hr overnight shift when im driving home at 6am. Im about to just put an oem catback on an call it a day and not even sweat the hp poss. Im on bolt ons with an ef2.5 but dont really care about the hp loss.


Puredriveperformance- what is "quite a bit of hp"? Did you lose 30hp just because of your exhaust change? Also, is your car a built motor, big turbo car? A stock exhaust on that would probably lose a lot more than one that just has bolts ons and maybe just an upgraded turbo.

 

^Exactly what I was going to suggest. Get a electronic cut out so you can close it when just driving around and then open it up when you want the power.

It will be a very noticeable amount. I helped a friend of mine put the stock exhaust back on his car a few days ago and it truly is a night and day difference.

 

Even if it costs me 20-30hp, I can live with that. 450whp is still very fast

 

I knew someone was going to ask.

Here's the VD. This is on E85 on stock block with a IX turbo. It's close to 30hp/30tq gain with the exhaust cutout.

 

I was asking how much you lost when you put the oem catback on instead of the 3" tbe.

 

That's a 7.1% loss at peak. However, if you look all the way at the left of the graph, the blue lines are higher than the red. Thus, the more restrictive exhaust may be better for local driving.

 

Gotcha! Yeah if it was a built engine I can see how this question would be of interest. However, I'm sure there are plenty of comparisons of stock to 3" TBE on a stock motor. I haven't looked through my logs (archived on external HD), but IIRC it was about a 15hp/10tq loss.

It honestly feels better with the stock exhaust down low, part throttle and stop and go. I have no way of measuring this (or do I?).

 

Thanks for the response man, I'm going to throw the stock catback on soon.

 

While I can't answer your power question, I can answer the use of the stock midpipe and rear section.

I do use a custom mandrel bent down pipe ( 2 1/2 " ) wrapped and the stock cat so bear that in mind....

I hate droning so i use the stock midpipe. The 2 resonators help with droning.

For the axle back section, i use a custom mandrel bent pipe section and a Magnaflow 2 1/2" muffler straight thru with rolled tip. This has the effect of reducing the back-pressure of the stock muffler w flapper valve and gives the exhaust a little growl .

Overall, the exhaust is very quiet close to stock level. WOT you do get a little growl but the turbo is louder. On the highway at cruise to 85 mph, no sound intrusion at all into the cabin.


I have ran the car this way for nearly 5 years. I would say I give up 20 whp over 3 inch systems but the car is sneaky quiet, doesn't draw any attention from cops and is so easy to take on 300 mile trips....

 

I just put on a HKS HI Power system and with the silencer it sounds stock! Look into it!

 

Another very quiet option is the hks sport. Very quiet ..

http://www.youtube.com/watch?v=R4T3t_3oFbU

 

Magnaflow makes some very big mufflers..... I'm running a huge(I'd guess almost 24"long) magnaflow muffler on my car, and it's crazy quiet, no drone on interstate. They're actually quite popular in NJ...this exhaust came from there actually

 

I'm getting my car tuned on the stock catback next week. I'll post up numbers then. I'm expecting a 7%-9% drop. Should put me at 430-440whp, but the car will have better manners around town, and will be quiet on the highway.

I drove my father-in-law's Deville all day yesterday. I wish I could get the evo to be that quiet on the highway. I'm all for hearing the exhaust while having fun, but a constant drone gets old fast.