Cerb 4.5 - Various States of Tune.
Discussion
As a guide for potential or existing Cerbera Owners I have put together a list of tuning options and power gains based on my 4.5 Cerb;
1) Standard 4.5 339.6bhp / 339lbs/ft (Surrey RR 12/03/05)
2) Unmapped Emerald ECU 375bhp / 365lbs/ft (Surrey RR 12/03/05)
3) Mapped Emerald ECU 384.6bhp / 353lbs/ft (Noble RR 22/03/05)
4) As 3, but with minor induction mod 389.2bhp / 356.7lbs/ft (Noble RR 22/03/05)
5) As 4, but with FFD short hoses (unmapped) 398.6bhp / 344.6lbs/ft (Noble RR 04/11/05)
6) As 5, but with remap 406bhp / 355lbs (Noble RR 10/11/05)
Value for money?;
1) £16k-£35k = £21,500 @ 339.6bhp = £63.31 per bhp
2) Emerald ECU £800 @ 35.4bhp = £22.60 per bhp gained
3) Emerald Mapping £240 @ 9.6bhp = £25 per bhp gained
4) Airbox Mod £50 @ 4.6bhp = £10.87 per bhp gained
5) FFD Short Hoses £350 @ 9.4bhp = £37.23 per bhp gained (Replace TVR purple hoses)
6) Mapping Time for Hoses £140 @ 7bhp = £20 per bhp gained
Total cost £1580 for 66 bhp gain at £23.94 per bhp.
How does the car feel at various states of tune?
1) It's a Cerb, it feels great
. Having owned a 4.2 previously I was aware that my 4.5 as std didn't feel particularly quicker, this was proved at Surrey RR where it put out 339bhp and 339lbs/ft torque. On the day it was about middle in the pecking order for 4.5s. Driveability was better than my previous 4.2, but this was probably down to the RR chip that had been fitted by APM 6 months earlier.
2) With the Emerald ECU plugged in (using a map from Satmans Cerb) it produced 375bhp and 365lbs/ft, this was literally unplug my MBE ECU and plug in the Emerald ECU, Joolz then spent a few minutes adjusting the fueling so that the car would start from cold and that was it! Driveability wasn't as good but this was to be expected as the map was not set up for my car, however, the performance difference was very noticeable, the car felt significantly quicker and very torquey, I have got to admit I was very impressed, especially as less than an hour earlier my car had put out 339bhp.
3) The Cerb was then sent to Noble Motorsport to have the Emerald ECU mapped specifically to my car, this resulted in a further increase in bhp upto 384.6bhp, but a slight decrease in torque to 353lbs/ft, the main difference was that the driveability of the car was vastly improved, being very smooth at low revs and the hesitancy on changing up a gear from 2nd to 3rd (slight dip in initial power in 3rd) had gone, the car felt strong all the way up the rev range.
4) Airbox Mod. Minor tweaks to the airbox by Joolz at TCS resulted in further gains in bhp/torque, up to 389.2bhp and 356.7lbs/ft torque, although minor they all count, and this mod proves to be the best VFM
.
5) Time to replace those haggard looking purple hoses. A few threads had bounced about with people talking about the gains that can be had from shortening the hoses, all of the theories expressed seemed viable, but I was worried about the potential drop in power and torque sub 4k rpm to allow an increase in power and torque above 4k rpm. After running the theories by a couple of "experts" at my work and Joolz at TCS, they came up with what they thought was the best option. Therefore I had some hoses made up and fitted them (piece of cake to fit). I then took the car out for a test drive knowing that a remap is definitely needed, however, the car felt a little bit lazy below 4k rpm, but appeared to really come to life at 4k+rpm (this later revealed itself as a fueling issue), the car felt quicker from a standing start under strong acceleration, but slower to pick up when cruising the motorway at 3-4k rpm, this lead me to think that I was down on torque. This is exactly what the Noble RR result showed, a drop in torque of around 10lbs/ft to 344.6lbs/ft, but an increase in power of around 10bhp to 398.6bhp. Peak torque had moved 600rpm up the rev range to 5368rpm, with bhp moving up 230rpm to 6763rpm. What was noticeable was how smooth the power and torque curves had become, the humps and bumps starting to disappear, however, compared to the longer hoses and even though the short hoses produced more power, the short hose set up without a remap was losing out in both power and torque at quite a few stages within the rev range. The fueling as earlier suggested was very wrong, around 5% upto 4k rpm, and not right from 4k rpm - 7.5krpm, this suggested that once corrected there were improvements to come.
6) The car was then remapped at Nobles to see what potential the short hoses really had, Darren who tuned the car was confident of seeing well inexcess of 400bhp and he was also confident that he could bridge all of the gaps within the rev range versus the longer hoses, and maybe exceed them. The results were excellent. In almost every area within the rev range the short hoses have exceed the power/torque of the longer hoses, with the results now showing 406bhp
and 355lbs/ft of torque. The engine produces 400bhp+ from 6600rpm to 7400rpm. More importantly is that the power and torque curves are incredibly smooth with no humps or bumps in the torque curve in particular, this can only be down to the design of the shorter hoses. The car drives as well as it ever has since the Emerald was installed, with next to no hesitancy from 1.5k rpm and above, and delivery of power is very strong but silky smooth. The car is now as well as it has ever been and probably how it always should have been.......when it left the factory.
What's left to do?
1) Linked Decats should see an increase of between 2-5bhp over std decats (£150)
2) Injectors - although I am not yet convinced that they will add more bhp (£400? + fitting)
3) Bespoke Manifolds - should see gains in bhp/torque of 2-5% (£800 + fitting)
4) Bespoke airbox (£600+), like the FFD hoses will require a bit of research and testing.
Not sure whether I'll do any of the above as the car now feels perfect, however, the linked decats will probably be fitted
, plus I wouldn't mind looking into some new manifolds
as well as the airbox......work in progress
....
I'll post the Graphs so that the differences are more apparent.
Stats;
1) 339.6bhp @ 6490rpm / 339lbs/ft @ 4470rpm
2) 375bhp @ 6650rpm / 365lbs/ft @ 4390rpm
3) 384.6bhp @ 6210rpm / 353lbs/ft @ 5013rpm
4) 389.2bhp @ 6533rpm / 356.7lbs/ft @ 4781rpm
5) 398.6bhp @ 6763rpm / 344.6lbs/ft @ 5368rpm
6) 405.6bhp @ 7149rpm / 354.7lbs/ft @ 5285rpm
Summary;
From 339bhp to 406bhp cost £1580 which includes Emerald ECU, airbox mod, remap and FFD Short hoses.
Thanks to Jools at TCS and Darren at Nobles for their time and patience with me....
Graphs as promised;
This graph shows a mapped Emerald unit as per state of tune no.3
This graph shows the Unmapped FFD short hoses (no.5) overlaying the mapped Emerald unit with airbox mod (no.4).
This graph shows the Mapped FFD short hoses (no.6) overlaying the mapped Emerald unit with airbox mod (no.4).
>> Edited by Cyclone1 on Monday 21st November 17:08
>> Edited by Cyclone1 on Monday 21st November 17:13
1) Standard 4.5 339.6bhp / 339lbs/ft (Surrey RR 12/03/05)
2) Unmapped Emerald ECU 375bhp / 365lbs/ft (Surrey RR 12/03/05)
3) Mapped Emerald ECU 384.6bhp / 353lbs/ft (Noble RR 22/03/05)
4) As 3, but with minor induction mod 389.2bhp / 356.7lbs/ft (Noble RR 22/03/05)
5) As 4, but with FFD short hoses (unmapped) 398.6bhp / 344.6lbs/ft (Noble RR 04/11/05)
6) As 5, but with remap 406bhp / 355lbs (Noble RR 10/11/05)
Value for money?;
1) £16k-£35k = £21,500 @ 339.6bhp = £63.31 per bhp
2) Emerald ECU £800 @ 35.4bhp = £22.60 per bhp gained
3) Emerald Mapping £240 @ 9.6bhp = £25 per bhp gained
4) Airbox Mod £50 @ 4.6bhp = £10.87 per bhp gained
5) FFD Short Hoses £350 @ 9.4bhp = £37.23 per bhp gained (Replace TVR purple hoses)
6) Mapping Time for Hoses £140 @ 7bhp = £20 per bhp gained
Total cost £1580 for 66 bhp gain at £23.94 per bhp.
How does the car feel at various states of tune?
1) It's a Cerb, it feels great
. Having owned a 4.2 previously I was aware that my 4.5 as std didn't feel particularly quicker, this was proved at Surrey RR where it put out 339bhp and 339lbs/ft torque. On the day it was about middle in the pecking order for 4.5s. Driveability was better than my previous 4.2, but this was probably down to the RR chip that had been fitted by APM 6 months earlier. 2) With the Emerald ECU plugged in (using a map from Satmans Cerb) it produced 375bhp and 365lbs/ft, this was literally unplug my MBE ECU and plug in the Emerald ECU, Joolz then spent a few minutes adjusting the fueling so that the car would start from cold and that was it! Driveability wasn't as good but this was to be expected as the map was not set up for my car, however, the performance difference was very noticeable, the car felt significantly quicker and very torquey, I have got to admit I was very impressed, especially as less than an hour earlier my car had put out 339bhp.
3) The Cerb was then sent to Noble Motorsport to have the Emerald ECU mapped specifically to my car, this resulted in a further increase in bhp upto 384.6bhp, but a slight decrease in torque to 353lbs/ft, the main difference was that the driveability of the car was vastly improved, being very smooth at low revs and the hesitancy on changing up a gear from 2nd to 3rd (slight dip in initial power in 3rd) had gone, the car felt strong all the way up the rev range.
4) Airbox Mod. Minor tweaks to the airbox by Joolz at TCS resulted in further gains in bhp/torque, up to 389.2bhp and 356.7lbs/ft torque, although minor they all count, and this mod proves to be the best VFM
. 5) Time to replace those haggard looking purple hoses. A few threads had bounced about with people talking about the gains that can be had from shortening the hoses, all of the theories expressed seemed viable, but I was worried about the potential drop in power and torque sub 4k rpm to allow an increase in power and torque above 4k rpm. After running the theories by a couple of "experts" at my work and Joolz at TCS, they came up with what they thought was the best option. Therefore I had some hoses made up and fitted them (piece of cake to fit). I then took the car out for a test drive knowing that a remap is definitely needed, however, the car felt a little bit lazy below 4k rpm, but appeared to really come to life at 4k+rpm (this later revealed itself as a fueling issue), the car felt quicker from a standing start under strong acceleration, but slower to pick up when cruising the motorway at 3-4k rpm, this lead me to think that I was down on torque. This is exactly what the Noble RR result showed, a drop in torque of around 10lbs/ft to 344.6lbs/ft, but an increase in power of around 10bhp to 398.6bhp. Peak torque had moved 600rpm up the rev range to 5368rpm, with bhp moving up 230rpm to 6763rpm. What was noticeable was how smooth the power and torque curves had become, the humps and bumps starting to disappear, however, compared to the longer hoses and even though the short hoses produced more power, the short hose set up without a remap was losing out in both power and torque at quite a few stages within the rev range. The fueling as earlier suggested was very wrong, around 5% upto 4k rpm, and not right from 4k rpm - 7.5krpm, this suggested that once corrected there were improvements to come.
6) The car was then remapped at Nobles to see what potential the short hoses really had, Darren who tuned the car was confident of seeing well inexcess of 400bhp and he was also confident that he could bridge all of the gaps within the rev range versus the longer hoses, and maybe exceed them. The results were excellent. In almost every area within the rev range the short hoses have exceed the power/torque of the longer hoses, with the results now showing 406bhp
and 355lbs/ft of torque. The engine produces 400bhp+ from 6600rpm to 7400rpm. More importantly is that the power and torque curves are incredibly smooth with no humps or bumps in the torque curve in particular, this can only be down to the design of the shorter hoses. The car drives as well as it ever has since the Emerald was installed, with next to no hesitancy from 1.5k rpm and above, and delivery of power is very strong but silky smooth. The car is now as well as it has ever been and probably how it always should have been.......when it left the factory. What's left to do?
1) Linked Decats should see an increase of between 2-5bhp over std decats (£150)
2) Injectors - although I am not yet convinced that they will add more bhp (£400? + fitting)
3) Bespoke Manifolds - should see gains in bhp/torque of 2-5% (£800 + fitting)
4) Bespoke airbox (£600+), like the FFD hoses will require a bit of research and testing.
Not sure whether I'll do any of the above as the car now feels perfect, however, the linked decats will probably be fitted
, plus I wouldn't mind looking into some new manifolds as well as the airbox......work in progress.... I'll post the Graphs so that the differences are more apparent.
Stats;
1) 339.6bhp @ 6490rpm / 339lbs/ft @ 4470rpm
2) 375bhp @ 6650rpm / 365lbs/ft @ 4390rpm
3) 384.6bhp @ 6210rpm / 353lbs/ft @ 5013rpm
4) 389.2bhp @ 6533rpm / 356.7lbs/ft @ 4781rpm
5) 398.6bhp @ 6763rpm / 344.6lbs/ft @ 5368rpm
6) 405.6bhp @ 7149rpm / 354.7lbs/ft @ 5285rpm
Summary;
From 339bhp to 406bhp cost £1580 which includes Emerald ECU, airbox mod, remap and FFD Short hoses.
Thanks to Jools at TCS and Darren at Nobles for their time and patience with me....
Graphs as promised;
This graph shows a mapped Emerald unit as per state of tune no.3
This graph shows the Unmapped FFD short hoses (no.5) overlaying the mapped Emerald unit with airbox mod (no.4).
This graph shows the Mapped FFD short hoses (no.6) overlaying the mapped Emerald unit with airbox mod (no.4).
>> Edited by Cyclone1 on Monday 21st November 17:08
>> Edited by Cyclone1 on Monday 21st November 17:13
Cyclone1 said:
As a guide for potential or existing Cerbera Owners I have put together a list of tuning options and power gains based on my 4.5 Cerb;
1) Standard 4.5 339.6bhp / 339lbs/ft (Surrey RR 12/03/05)
2) Unmapped Emerald ECU 375bhp / 365lbs/ft (Surrey RR 12/03/05)
3) Mapped Emerald ECU 384.6bhp / 353lbs/ft (Noble RR 22/03/05)
4) As 3, but with minor induction mod 389.2bhp / 356.7lbs/ft (Noble RR 22/03/05)
5) As 4, but with FFD short hoses (unmapped) 398.6bhp / 344.6lbs/ft (Noble RR 04/11/05)
6) As 5, but with remap 406bhp / 355lbs (Noble RR 10/11/05)
Value for money;
1) £16k-£35k = £21,500 @ 339.6bhp = £63.31 per bhp
2) Emerald ECU £800 = £22 per bhp gained
3) Emerald Mapping £240 = £24 per bhp gained
4) Airbox Mod £50 = £12.50 per bhp gained
5) FFD Short Hoses £350 = £38.88 per bhp gained (Replace TVR purple hoses)
6) Mapping Time for Hoses £140 = £20 per bhp gained
Total cost £1580 for 66 bhp gain at £23.94 per bhp.
How does the car feel at various states of tune?
1) It's a Cerb, it feels great
2) With the Emerald ECU plugged in (using a map from Satmans Cerb) it produced 375bhp and 365lbs/ft, driveability wasn't as good but this was to be expected as the map was not set up for my car, however, the performance difference was very noticeable, the car felt significantly quicker. I have got to admit I was very impressed, especially as less than an hour earlier my car had put out 339bhp.
3) The Cerb was then sent to Noble Motorsport to have the Emerald ECU mapped to my car, this resulted in a further increase in bhp, but a slight decrease in torque, the main difference was that the driveability of the car was vastly improved, being very smooth at low revs and the hesitancy on changing up a gear from 2nd to 3rd (slight dip in initial power in 3rd) had gone, the car felt strong all of the time.
4) Airbox Mod. Minor tweaks to the airbox by Joolz at TCS resulted in further gains in bhp/torque, although minor they all count, and this mod proves to be the best VFM
5) Time to replace those haggard looking purple hoses. A few threads had bounced about with people talking about the gains that can be had from shortening the hoses, all of the theories expressed seemed viable, but I was worried about the potential drop in power and torque sub 4k rpm to allow an increase in power and torque above 4k rpm. After running the theories by a couple of "experts" at my work and Joolz at TCS, they came up with what they thought was the best option. Therefore I had some hoses made up and fitted them (piece of cake to fit). I then took the car out for a test drive knowing that a remap is definitely needed, however, the car felt a little bit lazy below 4k rpm, but appeared to really come to life at 4k+rpm (this later revealed itself as a fueling issue), the car felt quicker from a standing start under strong acceleration, but slower to pick up when cruising the motorway at 3-4k rpm, this lead me to think that I was down on torque. This is exactly what the Noble RR result showed, a drop in torque of around 10lbs/ft, but an increase in power of around 10bhp. Peak torque had moved 600rpm up the rev range to 5368rpm, with bhp moving up 230rpm to 6763rpm. What was noticeable was how smooth the power and torque curves had become, the humps and bumps starting to disappear, however, compared to the longer hoses and even though the short hoses produced more power, the short hose set up without a remap was losing out in both power and torque at quite a few stages within the rev range. The fueling as earlier suggested was very wrong, around 5% upto 4k rpm, and not right from 4k rpm - 7.5krpm, this suggested that once corrected there were improvements to come.
6) The car was then remapped at Nobles to see what potential the short hoses really had, Darren who tuned the car was confident of seeing well inexcess of 400bhp and he was also confident that he could bridge all of the gaps within the rev range versus the longer hoses, and maybe exceed them. The results were excellent. In almost every area within the rev range the short hoses have exceed the power/torque of the longer hoses, with the results now showing 406bhp and 355lbs/ft of torque. The engine produces 400bhp+ from 6600rpm to 7400rpm. More importantly is that the power and torque curves are incredibly smooth with no humps or bumps in the torque curve in particular, this can only be down to the design of the shorter hoses. The car drives as well as it ever has since the Emerald was installed, with next to no hesitancy from 1.5k rpm and above, and delivery of power is very strong but silky smooth. The car is now as well as it has ever been and probably how it always should have been.......when it left the factory.
What's left to do?
1) Linked Decats should see an increase of between 2-5bhp over std decats (£150)
2) Injectors - although I am not yet convinced that they will add more bhp (£400? + fitting)
3) Bespoke Manifolds - should see gains in bhp/torque of 2-5% (£800 + fitting)
4) Bespoke airbox (£600+), like the FFD hoses will require a bit of research and testing.
Not sure whether I'll do any of the above as the car now feels perfect, however, the linked decats will probably be fitted
I'll post the Graphs so that the differences are more apparent.
Stats;
1)339.6bhp @ 6490rpm / 339lbs/ft @ 4470rpm
2)375bhp @ 6650rpm / 365lbs/ft @ 4390rpm
3)384.6bhp @ 6210rpm / 353lbs/ft @ 5013rpm
4)389.2bhp @ 6533rpm / 356.7lbs/ft @ 4781rpm
5)398.6bhp @ 6763rpm / 344.6lbs/ft @ 5368rpm
6)405.6bhp @ 7149rpm / 354.7lbs/ft @ 5285rpm
Thanks to Jools at TCS and Darren at Nobles for their time and patience with me....
>> Edited by Cyclone1 on Saturday 19th November 16:06
Julian,
Well done, this is very good indeed, as a potential Cerb owner when I sell my 4.O ltr T350, I would be looking to get a cerb as near as 400 asap, and this give me a reference of how to do it.
Mr F
darren no 7 said:
hi are the results at the wheels or flywheel?
Darren,
The results are at the flywheel.
A standard 4.5 or GT (If they exist?) isn't capable of producing the later figures (400bhp) at the wheels. A healthy Red Rose would also be nowhere near 400bhp at the wheels either. You would have to have a rebuilt Red Rose spec engine plus additional specialist work to get anywhere near that figure and then with rolling losses it would probably still struggle to achieve 400bhp at the wheels.
Hello Julian,
Very interesting, the shorter induction pipes, how much? And what diameter?
Julz as you probably know the length of the inlet tract is directly proportional to the peak power. Or more precisely, the point at which peak power will be reached.
The formula is length of inlet tract in inches, divided by 54000. The resulting figure will be the RPM at which peak power is produced. (I think)
Nick.
check this link for the details, ok it's not a Cerb but the principle is the same.www.allpar.com/history/memories/bob-scott.html
>> Edited by Nickccc on Saturday 19th November 19:02
>> Edited by Nickccc on Saturday 19th November 19:03
Very interesting, the shorter induction pipes, how much? And what diameter?
Julz as you probably know the length of the inlet tract is directly proportional to the peak power. Or more precisely, the point at which peak power will be reached.
The formula is length of inlet tract in inches, divided by 54000. The resulting figure will be the RPM at which peak power is produced. (I think)
Nick.
check this link for the details, ok it's not a Cerb but the principle is the same.www.allpar.com/history/memories/bob-scott.html
>> Edited by Nickccc on Saturday 19th November 19:02
>> Edited by Nickccc on Saturday 19th November 19:03
Hi Nick,
The hoses will be around £350.
I should have a second version finished for the new year, that should be slightly better.
Interestingly whilst at TCS we were thinking about how well they would suit your 4.5RR and what gains could be had, given that you are already at 419-420bhp but running the MBE I am not certain as to how much bhp you would gain (maybe 5-15bhp?)and I would be slighty worried that you may not gain any torque, as most of the remapped MBE cars with short hoses fitted appear to be slightly down on torque. It would definitely be worth trying though, as would fitting an Emerald?
Jules.
The hoses will be around £350.
I should have a second version finished for the new year, that should be slightly better.
Interestingly whilst at TCS we were thinking about how well they would suit your 4.5RR and what gains could be had, given that you are already at 419-420bhp but running the MBE I am not certain as to how much bhp you would gain (maybe 5-15bhp?)and I would be slighty worried that you may not gain any torque, as most of the remapped MBE cars with short hoses fitted appear to be slightly down on torque. It would definitely be worth trying though, as would fitting an Emerald?
Jules.
Hi Julz,
As soon as those rollers arrive, my contact (a Rasta bloke in Camden Town) has got some tickets for this all nighter in Chesterfield. Apparently there is an industrial estate up that way, and according to Delroy there is this bloke called Joo. Del reckons he has these magic chips and pipes that will, as he says “blow your output through the roof,” Dell’s mate Leroy also reckons he has seen “430 talks” out of his.
Nick.
As soon as those rollers arrive, my contact (a Rasta bloke in Camden Town) has got some tickets for this all nighter in Chesterfield. Apparently there is an industrial estate up that way, and according to Delroy there is this bloke called Joo. Del reckons he has these magic chips and pipes that will, as he says “blow your output through the roof,” Dell’s mate Leroy also reckons he has seen “430 talks” out of his.
Nick.
Nickccc said:
Hi Julz,
As soon as those rollers arrive, my contact (a Rasta bloke in Camden Town) has got some tickets for this all nighter in Chesterfield. Apparently there is an industrial estate up that way, and according to Delroy there is this bloke called Joo. Del reckons he has these magic chips and pipes that will, as he says “blow your output through the roof,” Dell’s mate Leroy also reckons he has seen “430 talks” out of his.
Nick.
Nickccc said:
Hello Julian,
Very interesting, the shorter induction pipes, how much? And what diameter?
Julz as you probably know the length of the inlet tract is directly proportional to the peak power. Or more precisely, the point at which peak power will be reached.
The formula is length of inlet tract in inches, divided by 54000. The resulting figure will be the RPM at which peak power is produced. (I think)
Nick.
check this link for the details, ok it's not a Cerb but the principle is the same.www.allpar.com/history/memories/bob-scott.html
>> Edited by Nickccc on Saturday 19th November 19:02
>> Edited by Nickccc on Saturday 19th November 19:03
The theory looks right and would probably explain why the peak torque figure moved up the rev range as well as the power still being at 400bhp at 7400rpm
, maybe, just maybe the pipes/hoses are too short
, maybe not, but the next ones will be a further improvement. >> Edited by Cyclone1 on Saturday 19th November 19:31
Hey Julian, nice report.
regarding lengths .. when i was chasing that 400hp number on Cliff's car it was great to see that the Cerbie obeyed the intake length rule i was using at the time (a std 4 cyl rule) ..
as I didn't trust it to work on the cerbera 75deg/flat plane completely at first i approached the 400hp by gradually trimming the inlets down to the point where we got the hp figure we needed, the length matched what the theory suggested .. it's intersting to note that the top end hp was going up all the time (as you would expect), but midrange was dropping off so i only shortened them as far as needed to go .. lengthening them back again would have dropped us off 400hp on Cliff's car ..
if anything they needed to be slightly shorter if we wanted to hold hp over 7k revs on Cliffs but that would have meant moving the airbox and I didn't want to do that at the time , as it was I only finished it the night before getting the car in at nobles again for the final mapping and power runs ..
I would say you've pretty much nailed the design on your car, the length would appear to be perfect and the fact you've ironed out the dips that are characteristic in all the other cerbera traces i've seen suggests that your own version of the diameter change down the inlet's length works very well also. Well done
Don't change a thing .. I'll have 20 sets please at that price they're the bargain of the century.
regarding lengths .. when i was chasing that 400hp number on Cliff's car it was great to see that the Cerbie obeyed the intake length rule i was using at the time (a std 4 cyl rule) ..
as I didn't trust it to work on the cerbera 75deg/flat plane completely at first i approached the 400hp by gradually trimming the inlets down to the point where we got the hp figure we needed, the length matched what the theory suggested .. it's intersting to note that the top end hp was going up all the time (as you would expect), but midrange was dropping off so i only shortened them as far as needed to go .. lengthening them back again would have dropped us off 400hp on Cliff's car ..
if anything they needed to be slightly shorter if we wanted to hold hp over 7k revs on Cliffs but that would have meant moving the airbox and I didn't want to do that at the time , as it was I only finished it the night before getting the car in at nobles again for the final mapping and power runs ..
I would say you've pretty much nailed the design on your car, the length would appear to be perfect and the fact you've ironed out the dips that are characteristic in all the other cerbera traces i've seen suggests that your own version of the diameter change down the inlet's length works very well also. Well done
Don't change a thing .. I'll have 20 sets please at that price they're the bargain of the century.
trackcar said:
Hey Julian, nice report.
regarding lengths .. when i was chasing that 400hp number on Cliff's car it was great to see that the Cerbie obeyed the intake length rule i was using at the time (a std 4 cyl rule) ..
as I didn't trust it to work on the cerbera 75deg/flat plane completely at first i approached the 400hp by gradually trimming the inlets down to the point where we got the hp figure we needed, the length matched what the theory suggested .. it's intersting to note that the top end hp was going up all the time (as you would expect), but midrange was dropping off so i only shortened them as far as needed to go .. lengthening them back again would have dropped us off 400hp on Cliff's car ..
if anything they needed to be slightly shorter if we wanted to hold hp over 7k revs on Cliffs but that would have meant moving the airbox and I didn't want to do that at the time , as it was I only finished it the night before getting the car in at nobles again for the final mapping and power runs ..
I would say you've pretty much nailed the design on your car, the length would appear to be perfect and the fact you've ironed out the dips that are characteristic in all the other cerbera traces i've seen suggests that your own version of the diameter change down the inlet's length works very well also. Well done
Don't change a thing .. I'll have 20 sets please at that price they're the bargain of the century.
Cheers Joolz, your findings from all of the testing you did were what I used when discussing the correct type of pipe/hose for the Cerb with my collegues at work, the only aspect that was different was the diameter change down the inlets length. This appears to work very well indeed and has performed much better than the original single diameter pipes I tried, which although reaped small bhp gains, lost more torque and the curves were nowhere near as smooth. The latest version will hopefully be as good if not better (starting to wonder now if they'll be worth all the effort), but it will be the other side of Christmas before they are done.
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