New Exhaust - More Power

[Cyclone1]

Some of you will have read from my post last week that I have had a new exhaust system made for my Cerb. At the moment I have only had the back section fitted (from intermediate pipes back as per Sports Exhaust), I have had it made in 2.5" into the back boxes and 3" all the way tail pipes. My car went on the Joolz'z rolling road last week at TCS and put out:

407.4bhp and 379lb/ft (has consistently been between 406 and 410bhp since short induction and linked de-cats were fitted).

Now it has produced:

420.4bhp and 389lb/ft

Am I happy................you bet!!!!!!!!!!!!

It has gained between 5-15bhp (mainly 10-15)and 5-20lb/ft all the way through the rev range.

Here's the graph with the two runs overlayed, pre exhaust in purple, post exhaust in red.



We have a couple more mods to finish, the first being the bigger bore intermediate pipes which should liberate a few more ponies, and then another which I'll let you know about after we have tested it.

I'd be suprised if there is a Cerb out there that can match this sort of power and torque throughout the rev range (Boss Cerb excluded).

I love this tuning lark............

Jules.

ps.......I now have a Cerb as it should have been when it left the factory.

Edited by Cyclone1 on Saturday 24th June 09:50

[satman]

Nice one Jules! ....damn...yet more expense coming up, I fear!

[itsallyellow]

Nice one!! 450 is the new target then..............

[TJW]

Nice output, scan the graph

[longbow]

Damn, might have to get me one of those 4.5 AJP thingies after all............

[Cyclone1]

Thanks for the positive comments.

I think I will have to put pressure on them to make a few systems, I think it would have to be half a dozen to make it worthwhile, but we'll see. There are still the intermediate pipes to be fitted yet.



Jules.

Edited by Cyclone1 on Saturday 24th June 09:51

[Cyclone1]

itsallyellow said:

Nice one!! 450 is the new target then..............

Maybe, but I reckon that 430bhp should be achieveable...........best thing is that we haven't even touched the engine yet.

ps......saw your car there today.....it's very, very yellow.....

Edited by Cyclone1 on Friday 23 June 20:37

[headcase]

Hmmmm, silver car but faster blue induction system, its all clear to me now Well done!

[cossiemetro]

well done m8 nice job it must be an animal now
especially on a silvery blue car lol

[_Deejay_]

Damn, that's pretty impressive for an exhaust! I presume you mapped it to suit?
What power was the car producing before you started on the mods?

D

[itsallyellow]

well itsallyellow!! supposidly it didnt do to bad on the dyno either!(for a first run) Id like to hear your system. is it much louder?

[Cyclone1]

itsallyellow said:

well itsallyellow!! supposidly it didnt do to bad on the dyno either!(for a first run) Id like to hear your system. is it much louder?

Promising first run.

It is louder but a totally different sound. Whilst on the rolling road yesterday I placed a noise level meter at the back of the car and took a reading, the next time Joolz puts a Cerb on the rollers (might be yours or one of the others in the workshop) then we'll have a direct comparison.

Jules.

[Cyclone1]

_Deejay_ said:

Damn, that's pretty impressive for an exhaust! I presume you mapped it to suit?
What power was the car producing before you started on the mods?

D

In all honesty I was hoping for the exhaust to just add say 5bhp, the one thing I didn't want was it to lose power. When I post the graph up I have overlayed the pre and post exhaust fitted runs, and from that you can see the clear difference all the way through the rev range. The addition of the exhaust has changed the breathing characteristics and this was evident in the fueling running ever so slightly leaner than previous, this is what you would expect to see, therefore the fueling was adjusted to suit (5 minute job).

The cars power before all of the mods which are as follows:

Emerald ECU
Whirlwind Short Induction Pipes
Linked De-Cats
Hi-Flow Filter
Custom Exhaust (back section)

339.6bhp and 339lb/ft - std.

Jules.

Edited by Cyclone1 on Saturday 24th June 09:05

[Cyclone1]

Took a pic of the graph instead of waiting to scan it on Tuesday and it's come out as good as scanning..........the purple lines are the pre-exhaust run, the red lines are post exhaust. I have posted it above in the original post.

Edited by Cyclone1 on Saturday 24th June 09:52

[satman]

Jules...really impressive!...considering the change that most Cerbera owners do...std exhaust to sports pipes to decats...where little or no difference to bhp is noticed, this is very good!

I doubt that the same improvements would be made fitting a big bore exhaust on a 'std' car though?...Id have thought that the short induction pipes/remap route unleashes the 'potential' and then the big bore exhaust enhances this...do you agree?

[_Deejay_]

Cyclone1 said:

_Deejay_ said:

Damn, that's pretty impressive for an exhaust! I presume you mapped it to suit?
What power was the car producing before you started on the mods?

D

In all honesty I was hoping for the exhaust to just add say 5bhp, the one thing I didn't want was it to lose power. When I post the graph up I have overlayed the pre and post exhaust fitted runs, and from that you can see the clear difference all the way through the rev range. The addition of the exhaust has changed the breathing characteristics and this was evident in the fueling running ever so slightly leaner than previous, this is what you would expect to see, therefore the fueling was adjusted to suit (5 minute job).

The cars power before all of the mods which are as follows:

Emerald ECU
Whirlwind Short Induction Pipes
Linked De-Cats
Hi-Flow Filter
Custom Exhaust (back section)

339.6bhp and 339lb/ft - std.

Jules.

Edited by Cyclone1 on Saturday 24th June 09:05

That's an absolutely outstanding achievement.

The power curve looks perfectly flat (where's that horrible drop in the midrange gone) - it must be a completely different drive to standard.

I cannot believe (well I can, but you know what I mean) that you've increased peak power by about 25%. I know the factory cars were far from polished/developed, but considering you've not touched the engine internals, that is truely astonishing.

So, what's next (and how long before you modify the internals)?

D

Edited by _Deejay_ on Saturday 24th June 10:30

Edited by _Deejay_ on Saturday 24th June 10:31

[Cyclone1]

_Deejay_ said:

Cyclone1 said:

_Deejay_ said:

Damn, that's pretty impressive for an exhaust! I presume you mapped it to suit?
What power was the car producing before you started on the mods?

D

In all honesty I was hoping for the exhaust to just add say 5bhp, the one thing I didn't want was it to lose power. When I post the graph up I have overlayed the pre and post exhaust fitted runs, and from that you can see the clear difference all the way through the rev range. The addition of the exhaust has changed the breathing characteristics and this was evident in the fueling running ever so slightly leaner than previous, this is what you would expect to see, therefore the fueling was adjusted to suit (5 minute job).

The cars power before all of the mods which are as follows:

Emerald ECU
Whirlwind Short Induction Pipes
Linked De-Cats
Hi-Flow Filter
Custom Exhaust (back section)

339.6bhp and 339lb/ft - std.

Jules.

Edited by Cyclone1 on Saturday 24th June 09:05

That's an absolutely outstanding achievement.

The power curve looks perfectly flat (where's that horrible drop in the midrange gone) - it must be a completely different drive to standard.

I cannot believe (well I can, but you know what I mean) that you've increased peak power by about 25%. I know the factory cars were far from polished/developed, but considering you've not touched the engine internals, that is truely astonishing.

So, what's next (and how long before you modify the internals)?

D

Edited by _Deejay_ on Saturday 24th June 10:30

Edited by _Deejay_ on Saturday 24th June 10:31

Next step is to get the intermedaite pipes fitted and then we have another mod up our sleeves, but want to see if it works first before getting excited about it. This should hopefully see 430bhp.

I put up a thread back in November of all of my various states of tune / mods since getting the car www.pistonheads.co.uk/gassing/topic.asp?h=0&t=223033, I need to update it as since then, I have had a new manifold (std but with subtle mods), linked de-cats, hi-flow filter and now exhaust.

[Cyclone1]

satman said:

Jules...really impressive!...considering the change that most Cerbera owners do...std exhaust to sports pipes to decats...where little or no difference to bhp is noticed, this is very good!

I doubt that the same improvements would be made fitting a big bore exhaust on a 'std' car though?...Id have thought that the short induction pipes/remap route unleashes the 'potential' and then the big bore exhaust enhances this...do you agree?

Not sure what type of "Sports Exhaust" was on my car but it wasn't the JP type, it looks as though these could have been a restricting factor (if only I'd realised this 6 months ago then I might have had 400bhp sooner).

Not so sure about whether the bigger bore exhaust would show the same improvements on a std Cerb, I reckon they would, but maybe Joolz could give a more informative opinion.

Jules.

Edited by Cyclone1 on Saturday 24th June 10:53

[_Deejay_]

Makes great reading, though I think Joolz may yet prove himself wrong (100hp/litre from a 2 value head).

The only slightly worrying thing is that the car's getting far more revvy (peak power and torque).

How far can you safely and reliably rev an AJP8 before internal components start to complain?

Oh, and I wonder what you could really get out of a 4.5 RR (or a 4.5 with internal tweaks)? Combining the mods on Daggarts car (in the classifieds) and yours would certainly be interesting (as long as you weren't paying for them )

D

Edited by _Deejay_ on Saturday 24th June 10:58

[simonsparrow]

Great results and nice power curve. Are your back boxes the same as 'normal' sports exhausts? i.e. cylindrical in section?