Some exhaust info
Discussion
VE 6L L92
Explains why Stig was so close to the aftermarket exhaust guys at the dyno day.
Anyless than dual 3" is pointless as Ive said before, you might as well stay stock.
http://www.chipmaster.com.au/ProjectVE_2.html
"In theory a 2 3/4 system was what we thought to be ideal for the 6L but as no manufacturer makes a system of this size would we have opted to try a dual 2 1/2 exhaust system initially to see how the engine would respond and after fitting a full system from headers to tailpipes we were a little disappointed to find that we had gained next to no power on the dyno and this was backed up on the track with a 13.4@104mph .
Back to the shop it was time to try the 3" system so we bolted a complete new system from front to rear and retuned the motor to suit , instantly we got a power increase to 239kw , time to take t to the track and to verify the increase , first time out it reeled of a 12.93@107mph , and then backed it up with another 2 passes. so we had achieved our initial target of a 12 sec street car with careful modifications"
Explains why Stig was so close to the aftermarket exhaust guys at the dyno day.
Anyless than dual 3" is pointless as Ive said before, you might as well stay stock.
http://www.chipmaster.com.au/ProjectVE_2.html
"In theory a 2 3/4 system was what we thought to be ideal for the 6L but as no manufacturer makes a system of this size would we have opted to try a dual 2 1/2 exhaust system initially to see how the engine would respond and after fitting a full system from headers to tailpipes we were a little disappointed to find that we had gained next to no power on the dyno and this was backed up on the track with a 13.4@104mph .
Back to the shop it was time to try the 3" system so we bolted a complete new system from front to rear and retuned the motor to suit , instantly we got a power increase to 239kw , time to take t to the track and to verify the increase , first time out it reeled of a 12.93@107mph , and then backed it up with another 2 passes. so we had achieved our initial target of a 12 sec street car with careful modifications"
Edited by ringram on Monday 23 November 13:39
;);)Phantom Mark said:
So how can I have the sounds of the Wortec but the 3in requirements to gain power ?? anybody know of a system ?
Just when I think I have a definate plan it all goes to crap, thanks Rich :P (Kiddin)
How much power you are after will dictate if you need 3 inch system (or even 3.5). We have run 600bhp NA through a wortec cat back and 700bhp on a supercharged setup.
We have only built 2 cars that NEEDED a 3 inch system, thats Harrys and Jez's.
That linked article does not state a remap/tune was carried out with the 2.5 system either, so not suprising they saw little if any gain.
Whereas with the 3 inch system they carried out a retune hence the increase in power.
As an aside, I had the Wortec SportPac fitted to my 04 CV8 last week by Monkfish, along with road response.
Now whether or not it has the extra 55 Hp as listed on the Dyno sheet for the SportPac, it is a definate improvement and seems to have a fair bit more grunt and shove, sounds great to on loud.
Hopefully the slight exhaust booming resonance at certain revs will tone down when its coked up a bit with more mileage.
thanks Andy, Roger and team.
Del
Whereas with the 3 inch system they carried out a retune hence the increase in power.
As an aside, I had the Wortec SportPac fitted to my 04 CV8 last week by Monkfish, along with road response.
Now whether or not it has the extra 55 Hp as listed on the Dyno sheet for the SportPac, it is a definate improvement and seems to have a fair bit more grunt and shove, sounds great to on loud.
Hopefully the slight exhaust booming resonance at certain revs will tone down when its coked up a bit with more mileage.
thanks Andy, Roger and team.
Del
Edited by Del-Dredd on Monday 23 November 16:16
400 rwhp is the aim to begin with, from what I have learn't thus far from other people posts (Rich, Monk, others) I was hoping to do the following...
In the following order due to wallet constraints...
Wortec Cat Back
OTRCAI
MAF'less Remap
Then the following as the wallet allows....
Undecided Brand Manifolds
Sport Cats
Cam (being the last on the list
And another remap to suit the above
Should finally be able to afford the Wortec this coming month, along with my interim service
In the following order due to wallet constraints...
Wortec Cat Back
OTRCAI
MAF'less Remap
Then the following as the wallet allows....
Undecided Brand Manifolds
Sport Cats
Cam (being the last on the list
And another remap to suit the above
Should finally be able to afford the Wortec this coming month, along with my interim service
Edited by Phantom Mark on Monday 23 November 16:24
Del-Dredd said:
That linked article does not state a remap/tune was carried out with the 2.5 system either, so not suprising they saw little if any gain.
Dont bother reading page 1 then or you would see that it was tuned. Ignorance is not bliss!http://www.chipmaster.com.au/ProjectVE__1.html
Ringman you drive me nut's, when I think I understand something er...I dont!
Look, simple answer please I am saving up for a cat back (2.5 inch dia.)together with a remap and airbox modification. This will be on a Monaro 5.7 VZ. Will I get anywhere near 390 bhp.....or not?
regards John..
Look, simple answer please I am saving up for a cat back (2.5 inch dia.)together with a remap and airbox modification. This will be on a Monaro 5.7 VZ. Will I get anywhere near 390 bhp.....or not?
regards John..
Still not clear even if you read page 1, reads to me that they tuned with standard exhaust before putting 2.5 on then no mention of retune until they put the 3 inch on.
Which would make it understandable, the tune gives the power, adding the exhaust without retuning has little to no effect.
I had just started reading from where you linked to in any case, not knowing any better and without page numbers on the pages.
Del
Which would make it understandable, the tune gives the power, adding the exhaust without retuning has little to no effect.
I had just started reading from where you linked to in any case, not knowing any better and without page numbers on the pages.
Del
Edited by Del-Dredd on Monday 23 November 19:10
Ok well, you guys should know when I say something I like to try and make it a discussion. Therefore Ill state something pretty strongly. Doesnt always mean I believe it myself, though in most instances I do. I also want people to think about things and challenge me
Of course 2.5 is better than 2.25 so you should gain from the increase. Its just that if you are changing the exhaust for best power you should probably change to dual 3". You may have other reasons for changing like noise etc. But I only want the best BHP per pound thats my mission.
Will you get a set BHP is unknown as its all about the combo. In order to get BHP you need airflow. Rule of thumb is 2.2CFM per BHP. In theory dual 2.5 is good for around 530fwhp from memory with zero loss. So thats say 400rwhp. That being said plenty of results show the larger diameter gaining power over the 2.5 on lower powered engines. Maybe due to cats, mufflers, bends etc reducing the straight line flow.
Anyway I like an argument as it makes me think harder about things so please dont hesitiate to discuss
Of course 2.5 is better than 2.25 so you should gain from the increase. Its just that if you are changing the exhaust for best power you should probably change to dual 3". You may have other reasons for changing like noise etc. But I only want the best BHP per pound thats my mission.
Will you get a set BHP is unknown as its all about the combo. In order to get BHP you need airflow. Rule of thumb is 2.2CFM per BHP. In theory dual 2.5 is good for around 530fwhp from memory with zero loss. So thats say 400rwhp. That being said plenty of results show the larger diameter gaining power over the 2.5 on lower powered engines. Maybe due to cats, mufflers, bends etc reducing the straight line flow.
Anyway I like an argument as it makes me think harder about things so please dont hesitiate to discuss
http://www.ls1tech.com/forums/generation-iv-intern...
Lets just say its a topic for discussion
Lets just say its a topic for discussion
Edited by ringram on Monday 23 November 22:29
Similar discussion in one of the other threads i have been looking at (dont ask me which one).
Think it was some comment about getting 500-600fwhp with 2.5 system, which is fine but you would no doubt get even more
if swapping it for a 3 inch system and tuning for that without changing anything else.
Del
Think it was some comment about getting 500-600fwhp with 2.5 system, which is fine but you would no doubt get even more
if swapping it for a 3 inch system and tuning for that without changing anything else.
Del
Down to the design and manufacture of the exhaust.
A claimed 2 1/2" system might in fact be no better than a 2 1/4" due to
hidden restrictions inside the silencers/pipework joiners bends ect.
I noticed this with my LC, I ended up making a no compromise 2 1/2" system, where
at no point was the od les than 2 1/2", even to the point of boring out the tail pipe trims.
www.lotuscarlton.co.uk/exhaust.htm Had some nice gains without map/tune changes.
Actually hope to re-visit srr soon, having now had a small map change.
Wortec system ?
These 2 bends could be a lot better imho
My monaro ls1 std system (I think) after downpipes, was 2 1/2" system.......except....
2 systems spec'd in 2 1/2" tubework made by different companies , could perform very
differently in terms of gas flow....
Be interesting to have a close look at std vxr8 system...
A claimed 2 1/2" system might in fact be no better than a 2 1/4" due to
hidden restrictions inside the silencers/pipework joiners bends ect.
I noticed this with my LC, I ended up making a no compromise 2 1/2" system, where
at no point was the od les than 2 1/2", even to the point of boring out the tail pipe trims.
www.lotuscarlton.co.uk/exhaust.htm Had some nice gains without map/tune changes.
Actually hope to re-visit srr soon, having now had a small map change.
Wortec system ?
These 2 bends could be a lot better imho
My monaro ls1 std system (I think) after downpipes, was 2 1/2" system.......except....
2 systems spec'd in 2 1/2" tubework made by different companies , could perform very
differently in terms of gas flow....
Be interesting to have a close look at std vxr8 system...
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