SD33 EXHAUST & EXTRACTORS

Joined: 18 Aug 2003 Location: Perth

Got a Mq LWB and have just purchased a set of extractors and a 3" mandrel bent system, will this affect my car in a bad in any way??

Marc

Joined: 02 Apr 2004 Location: Central Victoria

Nah, if anything it should increase efficiency by having more flow and better scavenging from extractors, may be a little louder tho, not sure what power or economy gains you would get tho, my mk shorty has a stock sd33, good contrast to my other mq which has 383 chev power armsup

Joined: 18 Aug 2003 Location: Perth

Didnt think it would-couldnt say no really cause i got em second hand for $110.

Bargain

Marc

Joined: 16 Oct 2003 Location: Hunter Valley

Extractors are all good, try to match the gasket with the head and manifold for max benifit, i would not use a three inch exhaust on that vehicle it is not well suited. Confused

Joined: 16 Jan 2004 Location: Lalor Park NSW.

You'll have very little power with low revs!!! Engines still need some degree of back pressure, if you put a huge exhaust on it you won't get any "go" out of it until your reaching the mid to top end of any gear!!!

4x4's need the power down low, bottom end tourque etc... Wink

You might be able to help this a little by selecting the right muffler, a more "restrictive" one!!

I put a 3" mandrel exhaust on a 300hp 308, it still "bogged down" a little at take off but when the 2500 stally kicked in you were fighting to lift your head off the head rest!! That exhuast, and motor, was built for mid to top end speed, Twisted Evil

STREET DRIVING!!!

Talk to an exhaust company, tell them what driving you do, and they'll tell you the best option!!!

Hope i've helped!!!

Joined: 18 Aug 2003 Location: Perth

Well as long as im not going to do any damage to the engine i will try the 3 " system but if i notice that ist not happening in the lower revs i will go and get a restrictive muffler put on.

Anything i need to know as far as installing the extractors go???

MArc

Joined: 02 Jun 2003 Location: Hobart

Shark wrote:

Well as long as im not going to do any damage to the engine i will try the 3 " system but if i notice that ist not happening in the lower revs i will go and get a restrictive muffler put on.

Anything i need to know as far as installing the extractors go???

MArc

Yea don't use a gasket just use high temp silicon sealer ( assuming youre manifold is nice and flat).

Joined: 18 Aug 2003 Location: Perth

Too late on the gasket goo, i ended up buying a gasket. I noticed a little drop in power down low in the rev range but nothing too serious. At some stage in the near future its going to need a new muffler and will put a more restrictive one on then.

Marc

Joined: 02 Apr 2004 Location: Central Victoria

Well as you'll be in the market for a new muffler soon heres a site which test a few mufflers for sound, flow etc,

http://www.autospeed.com/cms/article.html?&A=0381&P=1

and heres one that talks about exhaust theory, back pressure etc,

http://www.burnsstainless.com/TechArticles/Theory/theory.html

This is from the above site

"Gas speed is a double edged sword as well, too much gas speed indicates that that the system may be too restrictive hurting top end power, while too little gas speed tends to make the power curve excessively 'peaky' hurting low end torque. Larger diameter tubes allow the gases to expand; this cools the gases, slowing down both the gases and the waves."