2zz-ge Exhaust Help!

[dude]

Hey all

I don't own a lotus of any sort even though I really wish I did. I was simply wondering, for those of you with the 2zz-ge lotus's (lotuses? lotii?), what is the diameter of the exhaust manifold runners and the exhaust after the collector.

I realize your exhausts are pretty different from the front-engine 2zz cars. I am going to boost mine with a supercharger and it ill push about 8psi and about 230whp based on other people's dynos that have done it.

I am running this with a cold air intake and I was simply wondering what the aftermarket design was on your cars. Most people will swear by a 2.5" exhaust. I plan on getting the PPE Engineering header with the 1.75" runners but it merges into a 2.5"

Would I be better off running a 2.5" from the header-back or a 2.25"? The reason i ask is because I already bought the axleback in 2.25" and am wondering if this would hurt the performance of my boosted 2zz.

Also wondering, what supercharger comes on factory boosted 2zz lotus? the one I will be using is the Greddy kit which is the eaton mp62.


Thanks all!

[Noel]

The exhaust manifold on the SC models running the 2ZZ-GE is a standard OEM Toyota header. OEM - Cast iron, small diameter, non-equal length primaries, in short, crap.





Inside Diameter - 34mm
Outside Diameter - 37mm

Finally, I'll stick to asking your own forum buddies in your usual forum on what best headerback/catback option to run. What works on a mid-mounted Lotus will not work on a front-mounted Celica. Comparing pipe sizes and dimensions is ultimately, pointless.

[Bane]

Noel nailed it

I'm the one that supplies the PPE headers to the Lotus crowd and we use 1.75" primaries (44.45 mm) for our supercharged version. It goes into a 2.5" (63.5 mm) collector as that is what came out to be optimal using the simulation software.

You have to battle with a MUCH longer exhaust then the Lotus crowd does but on the flipside you also have more room to work with to make the runners equal length (the Lotus ones are very labor intensive to create).

[dude]

I see your point. The PPE header for the Corolla/Celica/Matrix is also designed with a 1.75" runner for forced induction applications.

Most of the people on my forum will go with 2.5" exhausts but I personally am not entirely convinced that is the way to go. In any case, thanks and I will check back if anyone has anything to add. Can you imagine the level of knowledge on a....dare I say, Corolla forum? Their logic and reasoning goes as far as "less backpressure = more horsepower" and it pretty much ends there. As soon as you mention exhaust velocity, pulse, scavenging, and pressure/vacuum issues, they choose to ignore you because they don't understand and start to call you names and keep reiterating that 2.5" is the best no matter what because everyone is using it.

Thanks guys!