Official Quad Exhaust Modification Topic

wills · Post by **wills** » Thu Jul 14, 2011 10:47 am

cj10jeeper wrote:
wills wrote:Likely, but reading about it - a 'freeflow' exhaust has more power at top-end, so very confused.com, plus my crude 0-60 timings & general feelings are performance unchanged.

Anyhow, shall do a dyno test on Monday to see how it's looking. If it's poor shall get an ecu flash.
At this level of relative cooking engine it won't make much difference at all to performance, just noise and vibration
If you're getting the to better end of the market then it's a scary science of pipe diameter, gas speed over rev range, backpressure, sound waves in the tubes, scarification and so on.

Don't worry about it - you'll make no real difference to your performance

I hope so...

Anyhow it's booked in for a Dyno test tomorrow 9am, & exhaust being redone by Longlife today.

Watch this space for results..! Bets anyone..?

Exactmax · Post by **Exactmax** » Thu Jul 14, 2011 1:22 pm

There shouldn't be any performance loss, if anything it will make the car slightly quicker with the excess weight cut out

Bradders75 · Post by **Bradders75** » Thu Jul 14, 2011 1:35 pm

Sorry to see the grief you're having with the quad wills. The workmanship looks pretty awful from the pics you've shown, I doubt they could have got you out of the work bay any quicker! Apart from the points already raised, I don't like how the tailpipes aren't staggered to follow the bumper curvature like the OEM set up.

wills · Post by **wills** » Thu Jul 14, 2011 6:48 pm

All sorted today. They couldnt have been more apologetic.

Right tip now in line, neat welding, new rear boxes and all much higher quality. Sound is also much quieter ie no heavy droning, but still sounds good at high revs.

Convinced low down torque is affected by having a quad but dyno test at 9am tomorrow will tell all!!

cj10jeeper · Post by **cj10jeeper** » Thu Jul 14, 2011 6:51 pm

wills wrote:All sorted today. They couldnt have been more apologetic.

Right tip now in line, neat welding, new rear boxes and all much higher quality. Sound is also much quieter ie no heavy droning, but still sounds good at high revs.

Convinced low down torque is affected by having a quad but dyno test at 9am tomorrow will tell all!!

Excellent that you have it fixed. Glad you did the research but a shame they allowed something lke that to happen.

RichardG · Post by **RichardG** » Thu Jul 14, 2011 6:53 pm

cj10jeeper wrote:Excellent that you have it fixed. Glad you did the research but a shame they allowed something lke that to happen.

Couldn't agree more, glad it's all sorted now.

wills · Post by **wills** » Fri Jul 15, 2011 10:04 am

Well dyno test not great news; just 242bhp at engine, at wheels around 205...! Shall post exact figures in a new topic later today.

They dont think exhaust has caused the drop, possibly air flow meter but no codes coming up. Ecu reset & same bhp figures.

Any ideas / suggestions..?

PawnSacrifice · Post by **PawnSacrifice** » Fri Jul 15, 2011 10:17 am

wills, I wouldn't worry about it - dynos vary wildly, although most tend to flatter - chap who did mine said he once did the baseline test for a BMW race series and a lot of guys complained he was lowballing them - they had achieved much higher figures elsewhere.

Not sure what the 3.0 should be, but it's within 10%. To be honest you really needed a before dyno on the same setup done by the same guy (even how they strap the car down can make a difference) for this to be relevant.

I'd be most concerned if there were any major peaks or troughs in the power curve.

aquazi · Post by **aquazi** » Fri Jul 15, 2011 10:23 am

wills wrote:Well dyno test not great news; just 242bhp at engine, at wheels around 205...! Shall post exact figures in a new topic later today.

242 isnt bad.... my car produced 250 something when it had around 8 k miles....

And dyno's at the crack its all a guessing game with estimates at the transmission loss.

Totally agree with Pawn.. you woul dneed before and after dyno's and check if the exhaust has effected the power delivery more then the overal power.

wills · Post by **wills** » Fri Jul 15, 2011 10:49 am

Thanks all. Not great pics of printout - 2nd run was slightly lower bhp at 241.3, and torque at 233.9.

No mention of bhp at wheels but he said just over 200 which seemed a little low...

I'd best start a new thread..!

Exactmax · Post by **Exactmax** » Sat Jul 16, 2011 7:13 pm

I thought I would post some pictures of the exhaust fitted from below:-

I couldn't see why the exhaust drones so much at around 3000RPM, its been mounted properly and isn't touching the car anywhere

wills · Post by **wills** » Sat Jul 16, 2011 7:24 pm

Have they taken out the rear boxes completely? I'm no expert but based on my quad I think droning is just something you'll have to get used to with that set-up.

Mine was tweaked with more supports etc, droning slightly improved but still there.

I hope someone has a solution for you, but in the meantime enjoy - I'm sure it looks & sounds great.

cj10jeeper · Post by **cj10jeeper** » Sat Jul 16, 2011 10:57 pm

Exactmax- well sorry to say but that doesn't impress me as a system. Lots of straight bits if pipe, no silencers and limited bends to match the undebody contours and profile. I bet it's loud.

bmwZ · Post by **bmwZ** » Sun Jul 17, 2011 12:09 am

This is mine:) Custom builded from a ESS muffler

I could not feel any difference in power. The exhaust muffler when original gave me 9rwhp on a dyno, but thats because I have a supercharger

wills · Post by **wills** » Sun Jul 17, 2011 12:36 am

bmwZ wrote:This is mine:) Custom builded from a ESS muffler I could not feel any difference in power. The exhaust muffler when original gave me 9rwhp on a dyno, but thats because I have a supercharger

Now I'm depressed - v nice..!!

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