kashracing

hey i was just wondering what you guys think of putting the electric exhaust cut out on our cars im thinking about putting one on just because its the ultimate sleeper part. You could have a quiet exhaust when u drive to work, but then when your at the track or just wanna show off you open it up and have a free flowing exhaust. So what do you guys think.

c5mtl

thats what i was just thinking today......do it.......need to look at some pics and see where to put it...really want to see what kind of gains at the track

kashracing

yea i was even thinking about putting a high flow cat for the on right after the header then put the cut out after that, and have a high performance exhaust when i want one

Gernby

iTrader: (1)

FWIW, exhaust cut-outs work well on cars with poorly designed exhaust systems, but work poorly on those with well designed exhausts. I would wait to see how much power can be attained by a very good aftermarket unit before I would go installing something like this. If Lexus did a good job on the stock unit (which they probably did), installing one of these might result in reduced power whether the valve was opened OR closed.

kashracing

Actually the stock exhaust is extremely restrictive, that is the reason for the quiet ride. Lexus designed it like that so it would be attractive to any owner

Gernby

iTrader: (1)

What is this theory based on? Have you ever driven a Honda S2000, which has FAR more HP / Liter than an IS350? Many S2000 owners have spent over a grand on exhaust mods to find that they actually LOST power. Have you seen any reputable, non-biased reports that replacing the stock exhuast on an IS350 showed gains on a dyno? Do you realize that exhaust systems on "decent" performance cars are actually tuned based on flow rates, pipe size, tube length, pulse width and frequency, and disrupting those parameters will de-tune the performance?

kashracing

your telling me that our cars cant atleast benefit from some high flow cats, and i have always seen cars that run straight pipes make more power then cars that have bends and restriction in them

Gernby

iTrader: (1)

I'm not saying that the IS can't benefit from exhaust mods. What I'm saying is that better engineers than you designed the exhaust, and I would bet that you would lose power whether the valve was open or closed. I'm not trying to say that I would do a better job designing it than you either.

I know that this car is NOT an S2000, but there have been MANY companies that spent a LOT of money trying to improve on its exhaust only to find that they couldn't, and eventually abandoned the project. Note that the reason why I keep brinking up the S2000 is because its exhaust was very quiet with a premuffler and dual triple pass mufflers.

All I'm saying (since you asked) is that you should probably wait to see what the best aftermarket exhaust does for the car. I know for sure that an open header will cost you power on any modern performance car, and installing an exhaust cut-out will have similar effects.

Gernby

iTrader: (1)

BTW, I'm sure the cats are adequately sized unless very significant mods were performed (forced induction, etc.).

nighthawk

I actually had an exhaust electric cutout on my Dodge Ram 1500 w/HEMI and it sounded awesome as hell, but that was a V8. On this car I would be worried if it would sound like a lawn mower or some riced out civic with a fart can exhaust. If it sounds good I would do it even if it showed no real power increase. It can always be left closed for more power or open for intimidation purposes. I will contact the company that I bought one from since it was the best quality unit out there and everyone bought from them on the dodge boards. The company is called DMH performance and it comes with 4 year warrenty if I'm correct. I will call him and see if he can make one for our cars. Anyone in Dallas area that would volonteer for testing? you'd probably get the unit for free. He does GB's too....

c5mtl

i do understand thar it is possible to lose power while the cutout is open but please explain why do u think power would be lost while closed....if the correct size is used it should not matter
thanks

Gernby

iTrader: (1)

Even if the cut-out is closed, there would still be a restriction through the valve, since it wouldn't be as smooth as a straight pipe. The restriction may not be severe, but nothing there would still be some disruption in flow.

Gernby

iTrader: (1)

I can't think of a worse comparison to make to justify a mod ... LOL

kashracing

i was just gonna go measure the exhaust piping and get 1 from quicktime performance. If you goto their site you can c that it does make power they even have a video of an IS300 with one
www.Quicktimeperformance.com

gnode

Sorry for bumping an old thread, especially one with so much ignorance above by a certain poster.

Anyway, did anything good come of this? Did the OP end up getting the cut out and how did it work? Any check engine light or O2 sensor issue?