4.6 engine build
Discussion
QBee said:
I could easily be wrong.
I asked for a car with driveability ahead of peak BHP. A stealth cam was specified by Rob.
My engine has most of the mods others with 330-360 bhp have (bigger AFM, smooth bore inlet hose, 72mm plenum, fully ported inlet manifold, stage 3 heads, lightened flywheel, fully decatted), but only makes 300 bhp. However, it does make 330 torques and is over 300 torques from 2000 rpm to 5000 rpm, which makes it a really flexible drive. For example, on track days I very rarely use second gear, even on pretty tight bends. The hairpin at Cadwell Park is about the only exception, and even there I sometimes use third.
The only mod I haven't had is an aftermarket ECU.
So that's why I jumped to the conclusion that it was the cam that was giving me the torque over bhp characteristic.
Come on guys - add your thoughts so we can resolve this one.
Do you think you could get a bit more BHP with more airflow? Perhaps the 5AM is your restriction. I think it was Blitz that mention the 5AM becomes restrictive at 280bhp? A new ECU could take advantage of this and perhaps make better use of larger injectors? Are you still catted QBee?I asked for a car with driveability ahead of peak BHP. A stealth cam was specified by Rob.
My engine has most of the mods others with 330-360 bhp have (bigger AFM, smooth bore inlet hose, 72mm plenum, fully ported inlet manifold, stage 3 heads, lightened flywheel, fully decatted), but only makes 300 bhp. However, it does make 330 torques and is over 300 torques from 2000 rpm to 5000 rpm, which makes it a really flexible drive. For example, on track days I very rarely use second gear, even on pretty tight bends. The hairpin at Cadwell Park is about the only exception, and even there I sometimes use third.
The only mod I haven't had is an aftermarket ECU.
So that's why I jumped to the conclusion that it was the cam that was giving me the torque over bhp characteristic.
Come on guys - add your thoughts so we can resolve this one.
At the end of the day, as long as you're happy with it, who cares!
QBee said:
I have a similar spec, but a 5 litre running on the 14 CUX, mapped by Mark Adams, with a stealth cam. Gorgeous torque over a very wide range of rpm, but only 300 bhp..... Unless I am mistaken, the stealth cam gives you torque at the expense of bhp. So it pulls brilliantly out of corners on track days, but ultimately is slightly slower at Santa Pod.
72mm plenum is readily available. IIRC it is a 3.9 LR Discovery plenum, or something similar. Mine certainly has "3.9" cast into the top. Someone else will know for sure.
I would of spent my money on the Emerald and have the full install and mapping done by Jools ,he would give you what you want .. 72mm plenum is readily available. IIRC it is a 3.9 LR Discovery plenum, or something similar. Mine certainly has "3.9" cast into the top. Someone else will know for sure.
More like 340bhp and 40mpg
I have a standard 4.6 with 885 cam, runs pretty good but Qbee's 500 was much quicker!
It was running leaner than my finances at the time but it was still very obvious to me the engine had much more instant power and pull all the way up the rev range!
I really need to get mine on a dyno!
Either mines slow or both of them are. Nonsense
I reckon mines got about 285bhp, Qbee's felt a lot more to me!
It was running leaner than my finances at the time but it was still very obvious to me the engine had much more instant power and pull all the way up the rev range!
I really need to get mine on a dyno!
Either mines slow or both of them are. Nonsense
I reckon mines got about 285bhp, Qbee's felt a lot more to me!
IME, for all the other advantages an integrated management system brings, one thing you will not see is bhp gains from the fueling side of things - the RV8's fueling requirements are quite relaxed and it's easy enough to get within the optimum AFR window for power/torque with the CUX or even the old flapper system. If you want it done properly, 90% of the rolling road work will concentrate on getting the low rpm/low load driveability as good as possible, either way.
Any gains in outright performance will come from having proper control on the ignition timing. With the 123ignition kit installed and dialled in, I gained 26 hp peak and a whopping 40 at 6,000 rpm (274 @5,500 -> 300 @6,000, at which point it was making only 260 before).
If you see truly massive gains from going aftermarket alone, I'd wager to guess the OE set up wasn't working as good as it could.
Any gains in outright performance will come from having proper control on the ignition timing. With the 123ignition kit installed and dialled in, I gained 26 hp peak and a whopping 40 at 6,000 rpm (274 @5,500 -> 300 @6,000, at which point it was making only 260 before).
If you see truly massive gains from going aftermarket alone, I'd wager to guess the OE set up wasn't working as good as it could.
macdeb said:
.
I did have a problem that went on and on for 18 months of which the MS ECU was at fault
18 MONTHS!!
Out of the fire, into the frying pan... or did your OEM set up actually work perfectly well? I did have a problem that went on and on for 18 months of which the MS ECU was at fault
18 MONTHS!!
Personally, if the CUX14 works well I'm inclined to leave well enough alone. I've yet have to find a naturally aspirated, road-biased configuration that was beyond the remit of a proper diagnostic/tuning/remap session.
macdeb said:
Hmm, My 450 running lucas was 286, 12 months later on same dyno after fitting MS was 260. So by my calculations the fitting of the MS lost me 26hp.
I did have a problem that went on and on for 18 months of which the MS ECU was at fault
18 MONTHS!!
What was that problem? Did you regain your lost power with the issue sorted out?I did have a problem that went on and on for 18 months of which the MS ECU was at fault
18 MONTHS!!
900T-R said:
Out of the fire, into the frying pan... or did your OEM set up actually work perfectly well?
Personally, if the CUX14 works well I'm inclined to leave well enough alone. I've yet have to find a naturally aspirated, road-biased configuration that was beyond the remit of a proper diagnostic/tuning/remap session.
Yes as long as you`re willing to pay big money to get the fuelling sorted out AND if you fit some sort of mappable ignition system like your 123 system.Personally, if the CUX14 works well I'm inclined to leave well enough alone. I've yet have to find a naturally aspirated, road-biased configuration that was beyond the remit of a proper diagnostic/tuning/remap session.
Personally i would just rather fit a new ecu that does both fuel n ignition and that i can get mapped whenever i want for not too much money.
Big money? really? Which aftermarket ECUs do you get including loom and installation for, say, £700? £2.5K excluding VAT seems to be the going rate for a decent system (and I've seen far too many issues with Megasnot... all the professional rolling road tuners I know won't touch it. Apart from that, the choice of system is probably far less important that the quiality of installation and calibration).
I find it hard to fathom why people are prepared to spend money on a box of chips but not for someone's expertise and experience when it comes to electronics and mapping... I'm not adverse to wielding the spanners myself but this is one area where I'd like to have a scapegoat when something goes awry.
I find it hard to fathom why people are prepared to spend money on a box of chips but not for someone's expertise and experience when it comes to electronics and mapping... I'm not adverse to wielding the spanners myself but this is one area where I'd like to have a scapegoat when something goes awry.
Sorry not to respond sooner - using the dry weather to try different seats and harnesses.
My engine was built by Rob and is described as an internally balanced, cross bolted, 5 litre. I asked for drivability rather than peak bhp.
I do indeed have Bosch Red Top injectors and a 20 AM AFM, the car s fully decatted and i am using the 14 CUX.
Bhp was 302 on Mark Adams' RR at Shrewsbury and 300 at Surrey Rolling Road. I have since then changed the elephant trunk to an ACT kit, and added a K&N filter. The elephant trunk was quite badly kinked, but I would be lying if I said I could tell the difference after fitting the new one.
I am surprised its only 300 bhp, but it drives really well, especially on track, so I am not so bothered.
My engine was built by Rob and is described as an internally balanced, cross bolted, 5 litre. I asked for drivability rather than peak bhp.
I do indeed have Bosch Red Top injectors and a 20 AM AFM, the car s fully decatted and i am using the 14 CUX.
Bhp was 302 on Mark Adams' RR at Shrewsbury and 300 at Surrey Rolling Road. I have since then changed the elephant trunk to an ACT kit, and added a K&N filter. The elephant trunk was quite badly kinked, but I would be lying if I said I could tell the difference after fitting the new one.
I am surprised its only 300 bhp, but it drives really well, especially on track, so I am not so bothered.
900T-R said:
Big money? really? Which aftermarket ECUs do you get including loom and installation for, say, £700? £2.5K excluding VAT seems to be the going rate for a decent system (and I've seen far too many issues with Megasnot... all the professional rolling road tuners I know won't touch it. Apart from that, the choice of system is probably far less important that the quiality of installation and calibration).
I find it hard to fathom why people are prepared to spend money on a box of chips but not for someone's expertise and experience when it comes to electronics and mapping... I'm not adverse to wielding the spanners myself but this is one area where I'd like to have a scapegoat when something goes awry.
Bit of a sweeping statement from someone who has never used it I find it hard to fathom why people are prepared to spend money on a box of chips but not for someone's expertise and experience when it comes to electronics and mapping... I'm not adverse to wielding the spanners myself but this is one area where I'd like to have a scapegoat when something goes awry.
I have known lots of problems with the Lucas system but it don't mean its s
t (far from it) more its poorly maintained from water ingress/corrosion etc etc 
most MS failures/problems are from piss poor installs like Daz's for example Macdeb is the only guy I have known to have issues that not been self inflicted or a poorly executed install so lets try to keep things real shall we 
I happen to like this product if it was ste I would be the 1st to admit it I also would not have been prepared to install another on my own brothers RV8, most that slate MS either have not had time or the brains to grasp its slightly overwhelming software and should stay away from engine management full stop 
and tuners that have seen appalling installs just say its st just so they can jump on the bandwagon IMO, most poor installs create noise voltage offsets etc it's then far easier to blame the module than their own handy-work like poorly sliced looms etc 
what makes things a whole lot worse is it can be built DIY and I have seen some terrible builds and these are the one's you will always hear about that lead to stuff like this 
Edited by Sardonicus on Thursday 6th February 15:41
900T-R said:
Big money? really? Which aftermarket ECUs do you get including loom and installation for, say, £700? £2.5K excluding VAT seems to be the going rate for a decent system (and I've seen far too many issues with Megasnot... all the professional rolling road tuners I know won't touch it. Apart from that, the choice of system is probably far less important that the quiality of installation and calibration).
I find it hard to fathom why people are prepared to spend money on a box of chips but not for someone's expertise and experience when it comes to electronics and mapping... I'm not adverse to wielding the spanners myself but this is one area where I'd like to have a scapegoat when something goes awry.
You're not comparing like with like though. How much is it for lucas remap, plus fitting and mapping a mappable ignition system? I find it hard to fathom why people are prepared to spend money on a box of chips but not for someone's expertise and experience when it comes to electronics and mapping... I'm not adverse to wielding the spanners myself but this is one area where I'd like to have a scapegoat when something goes awry.
Factor in the convenience of most good aftermarket systems having a capable mapper nearby and all of a sudden going aftermarket is a surefire winner.
I started doing aftermarket for tvrs about 10 years ago and was blazing a bit of a lone trail .. since then every man and his dog chasing the numbers (especially) seems to have jumped on board .. that must tell you something !
In spite of my troubles, I would still go aftermarket as it makes so much sense especially if your an habitual fiddler/modder/upgrader etc. The twim mapping available appeals to me.
As for regaining my power after the replacement I can't honestly say as I didn't have chance to get it on a dyno again, and I'm not about to spout some bull' like, 'it felt 20hp up'.
My problem was a faulty ecu that was only sorted after we'd changed EVERYTHING ELSE and went for direct fire
It certainly drove a lot better afterwards.
[Qbee's power seems on the money for me]
As for regaining my power after the replacement I can't honestly say as I didn't have chance to get it on a dyno again, and I'm not about to spout some bull' like, 'it felt 20hp up'.
My problem was a faulty ecu that was only sorted after we'd changed EVERYTHING ELSE and went for direct fire
It certainly drove a lot better afterwards.
[Qbee's power seems on the money for me]
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