Approx. Power increase from extractors?

[onfire]

Thinking about extractors for my AU1 6.. I had extractors on my V6 Commodore and apparently got a gain of about 13% from the extractors alone.

What sort of increase in % and kw should I get from a set of decent extractors?

The only mod Iv got is a Tickford Snorkel.

[XR6-VCT-2000]

i couldn't say an exact Kw increase , but generally if you want the full potential from the extractors you should look at matching the exhaust , allowing the extractors to breath/extract propperlly, i'de still say expect a bit of difference , but no where near the full potential of the extractors without an exhaust that matches the back pressure the extractors will output . Matching extractors for top performance can be 'fun and games..not !' getting things spot on to the engine/exhaust setup you have or plan on changing to suit the extractors ! ...anyway ... Someone else here might have added some sort of extractors to a standard engine and exhaust setup , maybe they can give you a bit more info on the results, cheers , gl ;)

[JC]

Originally Posted by onfire

Thinking about extractors for my AU1 6.. I had extractors on my V6 Commodore and apparently got a gain of about 13% from the extractors alone.

What sort of increase in % and kw should I get from a set of decent extractors?

The only mod Iv got is a Tickford Snorkel.

Somewhere between 0 and 10% (ie max about 12rwkw). If you fit extractors but keep the stock cats back system, then you will get closer to 0 than 10. A full mandrel bent 2.5 or 3" system (plus the extractors) should see gains closer to 10%. The only way to know for sure is to get a dyno run directly before the extractors are fitted, and one directly after. This will give you a reasonable indication of the power increase.

[Stav]

Good question. I havent seen dyno figures with extractors alone.Most people do both.However Stiddy on the forums has achieved 137 rwkws with just a 3inch exhaust. I have seen an AU pull 127 rwkws on a dyno with extractors and exhaust. Jonbays with dyno sheets gained 15 rwkws with full exhaust from standard. If Stiddy's xr6 is worth considering ,then an exhaust will do more for you than extractors.

[XR6-VCT-2000]

Originally Posted by useless

Good question. I havent seen dyno figures with extractors alone.Most people do both.However Stiddy on the forums has achieved 137 rwkws with just a 3inch exhaust. I have seen an AU pull 127 rwkws on a dyno with extractors and exhaust. Jonbays with dyno sheets gained 15 rwkws with full exhaust from standard. If Stiddy's xr6 is worth considering ,then an exhaust will do more for you than extractors.

Good point ! - imo i recon your better off to change the exhaust before doing exractors (if your not going to do them at the same time), personal choice , but as i said earlier - having extractors with just the standard exhaust still won't help the extractors work/extract propperly, allthough enlarging the exhaust system and running a single muffler setup for example will help the standard outlet manifold to extract better... just my 2 cents worth ;) .

Funny you mentioned the 3" system with no extractors , the old 302's and 351's used to sound quite nice imo ( deep rumble ) with a full stainless 3" system on a totally stock engine ! ..

[JC]

Originally Posted by XR6-VCT-2000

Funny you mentioned the 3" system with no extractors , the old 302's and 351's used to sound quite nice imo ( deep rumble ) with a full stainless 3" system on a totally stock engine ! ..

And they still sound good on the EFI 302s.

[loxxr6]

Originally Posted by useless

Good question. I havent seen dyno figures with extractors alone.Most people do both.However Stiddy on the forums has achieved 137 rwkws with just a 3inch exhaust. I have seen an AU pull 127 rwkws on a dyno with extractors and exhaust. Jonbays with dyno sheets gained 15 rwkws with full exhaust from standard. If Stiddy's xr6 is worth considering ,then an exhaust will do more for you than extractors.

I scored about 136rwkw from a full exhaust system (2.5" + hi flow cat).

[jonbays]

Well its not a bad mod for a true powe rgain in the vicinity of 10rwkw.


This is what it really did for my car.
http://www.fordforums.com.au/attachm...chmentid=11285

[Sleeperau]

Originally Posted by onfire

Thinking about extractors for my AU1 6.. I had extractors on my V6 Commodore and apparently got a gain of about 13% from the extractors alone.

What sort of increase in % and kw should I get from a set of decent extractors?

The only mod Iv got is a Tickford Snorkel.

I had the extractors on first & noticed a nice gain. Once the exhaust went on I noticed over double the gain, especially at rev's. I think it is more important to open up the strangled exhaust before worrying about extractors.13% sounds hard to believe. Jonbays dyno graph would be lucky to match that & he has all the good gear comps, cat & free flowing exhaust. Although the buick V6 is very weasy so who knows? The dyno doesn't lie though. Jonbays graph is proof as long as tests are done on the same dyno straight away.

[jonbays]

Originally Posted by Sleeperau

I had the extractors on first & noticed a nice gain. Once the exhaust went on I noticed over double the gain, especially at rev's. I think it is more important to open up the strangled exhaust before worrying about extractors.13% sounds hard to believe. Jonbays dyno graph would be lucky to match that & he has all the good gear comps, cat & free flowing exhaust. Although the buick V6 is very weasy so who knows? The dyno doesn't lie though. Jonbays graph is proof as long as tests are done on the same dyno straight away.

I did it all at once and the before and after is an honest one same day same dyno and what I would describe as a fair dyno. If i didn't have the money to do it all I would save it up. or maybe I would do the catback first nicer sound good results especially on BA by the way. Then the extractors but maybe with the stock cat if its in good nick. I am not sure the 3" Hi flow cat did any more than make it an easier job for the exhaust shop on the stock engine. When the cam and unichip came along it may have started to amke an impact.

[Tri Power 289]

I have to agree with XR6-VCT-2000. I have done extractors/hi flo cat on my AU III XR6hp Auto but left the rest of the exhaust standard, because I didn't want it any louder. IMO it has made stuff all noticeable difference to either the performance or economy.

I should be able to post a dyno figure shortly showing rwkw with this setup as I am having some work done at Aussie Car / Bluepower and want a baseline figure first.

If noise is not an issue then I would suggest doing cat back first or the whole system if possible. Not just extractors.

[stiddy]

Loxxr6 your cars a little freaky aswell ;) lol

Id say go for a cat back system first up, and get the extractors 2nd.. if you have enough for the extractors and exhaust to do in one hit, I say do that.

I dont see the point of putting extractors onto an otherwise stock exhaust system.