Walkinshaw Bi Modal Exhaust
Discussion
Popped up to Pentagon, Burton to have a listen a few weeks ago, not as loud as the Wortec or the TWR 110 dec example either. More of a traditional V8 sound from outside but from the inside all we could hear was the S/C !
I chose the Wortec for my own, although the TWR is apparently much better quality.
I chose the Wortec for my own, although the TWR is apparently much better quality.
Noose said:
ringram said:
Dont people buy exhausts for performance any more!?
lol what performance? extra 7bhp on a 420bhp or sc 600+hp... yup it's all about the noise... on the other hand if i had a 1.2 8v corsa an exhaust might help with performance lol...
My Wortec exhaust and Re map gave me at least 25Bhp (dyno to prove it) over standard on my LS3
cant see the point of exhaust without remapAnd how much was down to the exhaust and how much the tune?
Stock exhaust it good and replacing cat back is only good for noise in a stock engine IMO.
You are better off tune only.
A set of proper full length headers are where some more power from exhaust is.
Still no shame in just wanting noise, just don't expect any/much power from a cat back.
Have a look a the last dyno results and see what I got with the stock exhaust.
Stock exhaust it good and replacing cat back is only good for noise in a stock engine IMO.
You are better off tune only.
A set of proper full length headers are where some more power from exhaust is.
Still no shame in just wanting noise, just don't expect any/much power from a cat back.
Have a look a the last dyno results and see what I got with the stock exhaust.
Magic919 said:
vxrphantom said:
My Wortec exhaust and Re map gave me at least 25Bhp (dyno to prove it) ....
Do you have your 'before' graphs by any chance? I've only seen the ones with the exhaust and would be interested.
Sorry mate don't have pre-tune graphs. Rich is probably right I agree that the tune is responsible for most of the increase in power however in my opinion worth having both together.
A good question to ask yourself if you are after power is "How much exhaust flow does the engine need to support X BHP"
You will find the stock 2.5" good for over 500fwhp if I recall my calculations correctly.
112cfm per sq inch of exhaust and you need 2.2 cfm to support one engine bhp without loss.
Over that look at dual 3" which will support over 700fwhp etc.
Not to say it wont support more power, just that you will be leaving power on the table by choking it out.
Supercharged blokes should be running dual 3" and 1.7/8 headers if they dont want to be leaving power behind. Not sure why they dont. Perhaps they just like the noise too
You will find the stock 2.5" good for over 500fwhp if I recall my calculations correctly.
112cfm per sq inch of exhaust and you need 2.2 cfm to support one engine bhp without loss.
Over that look at dual 3" which will support over 700fwhp etc.
Not to say it wont support more power, just that you will be leaving power on the table by choking it out.
Supercharged blokes should be running dual 3" and 1.7/8 headers if they dont want to be leaving power behind. Not sure why they dont. Perhaps they just like the noise too
ringram said:
A good question to ask yourself if you are after power is "How much exhaust flow does the engine need to support X BHP"
You will find the stock 2.5" good for over 500fwhp if I recall my calculations correctly.
112cfm per sq inch of exhaust and you need 2.2 cfm to support one engine bhp without loss.
Over that look at dual 3" which will support over 700fwhp etc.
Not to say it wont support more power, just that you will be leaving power on the table by choking it out.
Supercharged blokes should be running dual 3" and 1.7/8 headers if they dont want to be leaving power behind. Not sure why they dont. Perhaps they just like the noise too
You will find the stock 2.5" good for over 500fwhp if I recall my calculations correctly.
112cfm per sq inch of exhaust and you need 2.2 cfm to support one engine bhp without loss.
Over that look at dual 3" which will support over 700fwhp etc.
Not to say it wont support more power, just that you will be leaving power on the table by choking it out.
Supercharged blokes should be running dual 3" and 1.7/8 headers if they dont want to be leaving power behind. Not sure why they dont. Perhaps they just like the noise too
SuperCharger goes on the LS3 next week. Are there any further Exhaust upgrades available at mo for the R8? Can only seem to find Cat-Back Wortec (already fitted). Headers, Sport Cats etc.
ringram said:
A good question to ask yourself if you are after power is "How much exhaust flow does the engine need to support X BHP"
You will find the stock 2.5" good for over 500fwhp if I recall my calculations correctly.
112cfm per sq inch of exhaust and you need 2.2 cfm to support one engine bhp without loss.
Over that look at dual 3" which will support over 700fwhp etc.
Not to say it wont support more power, just that you will be leaving power on the table by choking it out.
Supercharged blokes should be running dual 3" and 1.7/8 headers if they dont want to be leaving power behind. Not sure why they dont. Perhaps they just like the noise too
You will find the stock 2.5" good for over 500fwhp if I recall my calculations correctly.
112cfm per sq inch of exhaust and you need 2.2 cfm to support one engine bhp without loss.
Over that look at dual 3" which will support over 700fwhp etc.
Not to say it wont support more power, just that you will be leaving power on the table by choking it out.
Supercharged blokes should be running dual 3" and 1.7/8 headers if they dont want to be leaving power behind. Not sure why they dont. Perhaps they just like the noise too
would a twin 3" be over kill for a n/a car that will eventually go FI dont want to cause issues now but would rather not buy twice!
Sorry, Im also specifically talking about the vxr8 which has dual 2.5" factory.
Not sure on the Monaro's if they are not running dual 2.5" then catback will help.
As for going dual 3" now in view of future requirements thats fine. What you should be aware of though is going to big on the headers might not be optimal. Stock a 1.75" is good, which most aftermarket headers are.
FI 1.7/8 is better. Mainly a larger exhaust will just cost more. A nice side benefit is that it would be louder than the smaller diameter stuff if thats also what you are after.
Not sure on the Monaro's if they are not running dual 2.5" then catback will help.
As for going dual 3" now in view of future requirements thats fine. What you should be aware of though is going to big on the headers might not be optimal. Stock a 1.75" is good, which most aftermarket headers are.
FI 1.7/8 is better. Mainly a larger exhaust will just cost more. A nice side benefit is that it would be louder than the smaller diameter stuff if thats also what you are after.
IMO exhausts are just for performance (when under very silly numbers).
The difference is trivial and more often than not it's down to other changes that affect the dyno run.
I've seen this before with a run, some changes another run seeing an improvement, putting the changes back to exactly the same as the first run and seeing the same results as the second on a third dyno run.
There's just too many variables on a dyno run to get accurate results - try two runs with 1psi difference in the tyres and you'll see my point.
The difference is trivial and more often than not it's down to other changes that affect the dyno run.
I've seen this before with a run, some changes another run seeing an improvement, putting the changes back to exactly the same as the first run and seeing the same results as the second on a third dyno run.
There's just too many variables on a dyno run to get accurate results - try two runs with 1psi difference in the tyres and you'll see my point.
Dyno is just one tool. Anyone with a tune or logging system can see the airflow/airmass changes directly from mods in the form of g/sec or g/cyl. Which are related to bhp and torque pretty directly. That's how I would gauge improvements in the first instance. The dyno really, for me anyway, is for spark timing and to a lesser extent fueling.
Plus to get a relative idea of power. Hence why dyno days rock.
Plus to get a relative idea of power. Hence why dyno days rock.
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