Does the X-force dump that is one pipe (3.5 to 4 inch) or the pipe with seperate wastegate pipe flow better?

This will be for a turbo with no cat (maybe as in NZ) and 3.5 inch system.

it depends on how much power you are looking for, IMO the 3.5 with the separate wastegate pipe is better for low to mid response, but the full 4" will flow more at higher revs and be capable of more top end power

Again, this is just my 2c!

Back to back tests on the twin dump V single 4" dump

http://www.bestmufflers.com/Information/Cu...yno_Results.htm

that's a good link Jim

Seems pretty consistent, but considering those figures are attainable with the stock dump pipe, the difference would be much greater with the tuning knowledge available now

Get the twin Bevan.

I've ordered the 4", can't have you beating me

Good work on the 3 1/2 as well, I'm getting the 2 1/2 twins.

Will make a good comparo.

Who are you getting from and how much?

I got through Redline Performance.

I ordered the 3.5 and seperate wastegate and full 3.5 inch system - and they delivered all of it wrong - 4 inch, and twin 2.5. If you want it - and I can get a better price - I will sell it to you.

Sadly money all sent.

$1700 to my door.

I ordered mine last Wednesday or Thursday. Then... on the way down to Wellington the truck blew up. So... my gear arrived today. Any chance that they mixed your and mine order up from that timing? I basically have all the bits you ordered!

PS - we will have an interesting comparison by the end of this. My mods will be:

1. Process West Plenum and Cooler Kit

2. X-Force 4 inch Dump and 3.5 exhaust (I think I will keep this dump)

3. Possibly no cat (depends on noise)

4. Modified Flapper Valve and Actuator

5. Process West Surge tank and pump

6. Edit and custom tune

7. Atomic Valve Springs

8. Group Buy 60lb injectors

The car is a six speed manual BA Mk2.

I believe your car will have similar bits - list them, and lets give the forum a look at a comparison.

Cheers

Bevan

Edited 05/05/08 08:14 AM05/05/08 08:14 AM by cobrav8

Update - I talked to my Tuner, and he suggested that the 3.5inch dump with seperate wastegate is better for low and mid-range power, and the 4 inch will make less down low, but a higher total power.

So... I am going for low down power. So the buggers can replace everything that they sent wrong!

Bevan

http://www.fordxr6turbo.com/forum/index.ph...mp;#entry671152

My last post in there gives my point of view regarding the 4 inch xforce vs the xforce twin dump arrangement.

But to conclude my post in there and make some relevance to your situation you will find that with less exhaust backpressure the turbine wheel can spin more freely thus allowing more low end efficiency, I.e quicker spool. Although I highly doubt that by having a more back pressure inside the dump pipe and polluting the air/fuel ratio inside the combustion chamber that the hollow 4 inch dump will do can give you more up top. Probably gives you the illusion of more power up to due to the lack of bottom end comparative.

That said though both dump pipes are a step ahead of the stock arrangement.

Edited 05/05/08 09:14 AM05/05/08 09:14 AM by Fatsex