OK for those of you who are extractor fans (yes deliberate pun here) can you advise if you had your vehicle on the dyno before and after the extractors were fitted. What I am interested in is the difference they make to the torque curve, where it develops max torque and how much difference.

OK for those of you who are extractor fans (yes deliberate pun here) can you advise if you had your vehicle on the dyno before and after the extractors were fitted. What I am interested in is the difference they make to the torque curve, where it develops max torque and how much difference.

Matey this looks like a bit of a FAIL thread lol

I don't think anyone has done before & after dyno runs with the extractors. There is definitely a good increase in torque though & a boost to the top end KW's. Especially in conjunction with the intake & exhaust mods I think you will be very happy with the outcome, a piggyback & tune will make just that bit more of a difference in throttle response & overall drivability.

I got a 'before' dyno run... but no 'after'. No plans for extractors yet.
What about kj380? I know he did extractors and did some power chasing.

Point being that you often alter your torque curve with extractors and they tend to make the torque peak higher in the rev range from memory. Good for performance but not so good if you are towing and need down low torque, hence the thread (albeit a seemingly failed one!!)

Point being that you often alter your torque curve with extractors and they tend to make the torque peak higher in the rev range from memory. Good for performance but not so good if you are towing and need down low torque, hence the thread (albeit a seemingly failed one!!)

They are long tube extractors so the torque is more biased towards the low to mid end if that helps.

I got a 'before' dyno run... but no 'after'. No plans for extractors yet.
What about kj380? I know he did extractors and did some power chasing.

Check out my dyno results here: http://www.aussiemagna.com/forums/showthread.php?t=52148

Page 1, post #9.

This was after the extractors & dual exhausts & hi-flow cat were fitted, I didn't do a 'before' run.

The dyno curve starts at around 2,700rpm with around 345Nm and gradually rises to 375Nm at around 4,500rpm before it drops off. It's a fairly even rise with no peaks or troughs. At 4,000 rpm it's around 370Nm.

Stock is 343Nm at 4,000rpm.

So going by my dyno charts, and the 'feel of the pants' response at lower revs, I reckon the extractors help to beef up the torque curve right through the rev range. Of course other mods like the larger intake snorkel, straight through mufflers and hi-flow third cat also contribute. I would guess the breakdown of the increase in power & torque over stock would be in the order of 30% extractors, 30% intake snorkel, 30% mufflers and 10% cat.

KJ.

Check out my dyno results here: http://www.aussiemagna.com/forums/showthread.php?t=52148

Page 1, post #9.

This was after the extractors & dual exhausts & hi-flow cat were fitted, I didn't do a 'before' run.

The dyno curve starts at around 2,700rpm with around 345Nm and gradually rises to 375Nm at around 4,500rpm before it drops off. It's a fairly even rise with no peaks or troughs. At 4,000 rpm it's around 370Nm.

Stock is 343Nm at 4,000rpm.

So going by my dyno charts, and the 'feel of the pants' response at lower revs, I reckon the extractors help to beef up the torque curve right through the rev range. Of course other mods like the larger intake snorkel, straight through mufflers and hi-flow third cat also contribute. I would guess the breakdown of the increase in power & torque over stock would be in the order of 30% extractors, 30% intake snorkel, 30% mufflers and 10% cat.

KJ.

Thanks Dave

When Foozer and I drove each other's cars a year or two ago, the only difference was extractors on Foozer's. It had a lot more torque down low whereas further up the rev range the difference was not nearly so noticeable.

When Foozer and I drove each other's cars a year or two ago, the only difference was extractors on Foozer's. It had a lot more torque down low whereas further up the rev range the difference was not nearly so noticeable.

Yep that is true.

Matey if you want lots of torque down low, bolt the blower kit on. You'll have plenty of torque, plenty of power & plenty of extra fuel consumption but you'll find the whine adictive & make the extra fuel consumption insignificant. :badgrin:

I find wine addictive unless it comes in a goon bag LOL

Interesting that you found that the torque along the band increases with no peaks or troughs but would not surprise me with this engine good figures KJ

They are long tube extractors so the torque is more biased towards the low to mid end if that helps.

Headers with long primary tubes are biased toward top end power and will typically be about 20-30" long(including ex port length). For more bottom end you need short small dia primary tubes and long secondary. Around 15" including ex port length is typical primary length, and 20-25" secondary for an engine making max power at 5300-6300rpm.

Cheers,
Alan

I'll probably run a harsh illegal, polluting no cat system on mine when my extractors arrive...

I heard somewhere that with LPG you don't legally need a catalyctic converter?

Can anyone verify that?

Headers with long primary tubes are biased toward top end power and will typically be about 20-30" long(including ex port length). For more bottom end you need short small dia primary tubes and long secondary. Around 15" including ex port length is typical primary length, and 20-25" secondary for an engine making max power at 5300-6300rpm.

Cheers,
Alan

Hence my query on the extractors. The length does have an effect on torque. There only appears to one set that most people are using. Does anyone have the measurements on them out of interest?

I have ordered my extractors from RPW (they're on backorder).

I have a Series 1 VRX manual, and only thing I have done is change the snorkel over. If you like, I can see if I can arrange a dyno run prior to fitting the extractors (may even be able to do a pre/post snorkel one too) and then again after fitment.

Probably give you the best "stock" numbers for a comparison of the one mod.

Let me know if you want me to sort it out.

I have ordered my extractors from RPW (they're on backorder).

I have a Series 1 VRX manual, and only thing I have done is change the snorkel over. If you like, I can see if I can arrange a dyno run prior to fitting the extractors (may even be able to do a pre/post snorkel one too) and then again after fitment.

Probably give you the best "stock" numbers for a comparison of the one mod.

Let me know if you want me to sort it out.

That would be really excellent if you could. I am sure there would be a lot of people here that would be interested too. Plus it gives you an accurate indication of gains made.