Finally found my old rolling road print outs to compare.
Discussion
It only took two years to find the old print outs, I’d put them safely in the owners manual!
First two were one run at a fun PH day out & more crucially three months after a 12k service by APM Andy. I know Andy changed it to even cam timing at some point so I’m assuming it was then.
It doesn’t say but would seem logical one is wheel power & the other corrected.
I noticed it says Gear 3, I thought it was more normal to use 4th. The last two both have a max speed of 145mph so I’d assume that’s 3rd gear too (I can’t see you getting an extra 50mph by just changing from 4th to 5th) so hopefully they are at least all in the same gear.
This next one is lacking in info but I’m sure it was a little while after the first (Edit - just found the invoice it was 01/11/06), Austec had an open day & we met Ridds there. They wouldn’t run our Cerb up on the day as they said it was pinking too much. That was round the time everyone was talking about the purple pipes & I could see them almost totally collapsing. It had been feeling a bit slower too so & bodged / fixed the pipes with jubilee clamps & took it back:
Its hard to say if that is a low power corrected figure or a better wheels power, its a hell of a drop for corrected though. The max power is quite low at about 6350 rpm. I later found the inside of one of the cats had broken lose & the ends of the honeycomb had got bent over blocking it a bit.
Then on to the most recent. It’s now has an emerald K6, J’s short intakes, his linked decats & an SP back box as well as an extensive amount of work on the engine to all be correct. But possibly more importantly the cam timing is set to 1mm lower rather than even as Jason at TVR power told me he gets much better mid range power like that, but he said it is at the expense of top end power.
From the first time it seems it had 290ft-lb or 394Nm
The max torque now looks to be 433Nm or 319ft-lb
Mind you the BHP has jumped from 344 to 368 (first to last) so the increase in torque may just be comparable to that.
I asked John to map it conservatively as I’d been having so many problems engine, but I’d be lying if I said I was happy with the low headline power figure!
It’s been good as gold ever since so there is of course a temptation to set the cam timing back to even & have it remapped again to see what happens!
Either way it certainly felt a lot faster on the track last time I tried.
Any comments on me reading the graphs wrong or anything else are welcome.
First two were one run at a fun PH day out & more crucially three months after a 12k service by APM Andy. I know Andy changed it to even cam timing at some point so I’m assuming it was then.
It doesn’t say but would seem logical one is wheel power & the other corrected.
I noticed it says Gear 3, I thought it was more normal to use 4th. The last two both have a max speed of 145mph so I’d assume that’s 3rd gear too (I can’t see you getting an extra 50mph by just changing from 4th to 5th) so hopefully they are at least all in the same gear.
This next one is lacking in info but I’m sure it was a little while after the first (Edit - just found the invoice it was 01/11/06), Austec had an open day & we met Ridds there. They wouldn’t run our Cerb up on the day as they said it was pinking too much. That was round the time everyone was talking about the purple pipes & I could see them almost totally collapsing. It had been feeling a bit slower too so & bodged / fixed the pipes with jubilee clamps & took it back:
Its hard to say if that is a low power corrected figure or a better wheels power, its a hell of a drop for corrected though. The max power is quite low at about 6350 rpm. I later found the inside of one of the cats had broken lose & the ends of the honeycomb had got bent over blocking it a bit.
Then on to the most recent. It’s now has an emerald K6, J’s short intakes, his linked decats & an SP back box as well as an extensive amount of work on the engine to all be correct. But possibly more importantly the cam timing is set to 1mm lower rather than even as Jason at TVR power told me he gets much better mid range power like that, but he said it is at the expense of top end power.
From the first time it seems it had 290ft-lb or 394Nm
The max torque now looks to be 433Nm or 319ft-lb
Mind you the BHP has jumped from 344 to 368 (first to last) so the increase in torque may just be comparable to that.
I asked John to map it conservatively as I’d been having so many problems engine, but I’d be lying if I said I was happy with the low headline power figure!
It’s been good as gold ever since so there is of course a temptation to set the cam timing back to even & have it remapped again to see what happens!
Either way it certainly felt a lot faster on the track last time I tried.
Any comments on me reading the graphs wrong or anything else are welcome.
Edited by Luckyone on Tuesday 7th August 17:03
Jhonno said:
When was it set back to uneven timing?!
Even is the best way.. Joolz has found this with much testing!
I know probably stupid really, a Cerb life time of listening to APM Andy (who I believe was actually the first to do it) & after talking to Joolz many times I decided to take the advice of some bloke I only spoke to once, just because he sounded like he knew what he was talking about at that moment. Jason is (or was a few years ago at least) Powers mapping man, I was rebuilding my heads for the second time (having set them to even the first time). I was talking to him about something else as they did all the machining work for me & it happened to be right at the time I was setting the cams. Even is the best way.. Joolz has found this with much testing!
Even Dave Walker said it would probably be better with even cam timing as he generally finds that best on the whole.
I’m just wondering if anyone thinks the mid range looks good in anyway to support what Jason said about it making the car more drivable. I didn’t want an engine I had to always rev to the red line to get the power from it. But if the mid range is the same & it just gives you more top end there really is no point!
I did speak to Joolz after & he said there is no way of telling, he didn’t like to say it would definitely make more power by setting it back to even. But as I said it’s tempting to try!
Edited by Luckyone on Tuesday 7th August 17:11
I don't think there is much in the way of mid range loss being even, but you gain top end.. Joolz isn't all about headline figures, he makes them driveable too. Your headline torque figure isn't that great tbh.. That is about 20/30lbft down on what you might expect from a 4.5, so I would definitely say it was worth a try!
(Obviously dyno figures are only comparable on the same dyno in the same conditions, so maybe Emerald reads low..)
(Obviously dyno figures are only comparable on the same dyno in the same conditions, so maybe Emerald reads low..)
I don't know how the new emerald rollers compare to my dyno, but the old emerald rollers were slightly lower than mine, and mine are slightly lower than surrey.
I think all we are proving here is that different dynos read differently.
A good mapped 4.5 on long pipes makes 390 (ish) on my dyno. In fact I've had loads make 391 for some strange reason (I can't imagine it's the consistency of TVR's builds!)
On that basis you're a good 10 percent down all the way through the rev range on where you *should* be .. but maybe the new emerald dyno is say 5 percent down and John mapped it another 5 percent safe. Or maybe everyone else is high. For the work you've put in you'd hope it was a good 'un.
If you fancy a run oop norf I'd run your car up for free just to see how we compare. And you can tell me about that Stag you restored
edited to add : just seen it was 2016, thought it was a recent run .. I can't remember when the new emerald rollers went in but if it's the old set then yes it'd read slightly higher on my dyno, but 30hp higher? maybe not, but could be 375 or so, just guessing really.
I think all we are proving here is that different dynos read differently.
A good mapped 4.5 on long pipes makes 390 (ish) on my dyno. In fact I've had loads make 391 for some strange reason (I can't imagine it's the consistency of TVR's builds!)
On that basis you're a good 10 percent down all the way through the rev range on where you *should* be .. but maybe the new emerald dyno is say 5 percent down and John mapped it another 5 percent safe. Or maybe everyone else is high. For the work you've put in you'd hope it was a good 'un.
If you fancy a run oop norf I'd run your car up for free just to see how we compare. And you can tell me about that Stag you restored
edited to add : just seen it was 2016, thought it was a recent run .. I can't remember when the new emerald rollers went in but if it's the old set then yes it'd read slightly higher on my dyno, but 30hp higher? maybe not, but could be 375 or so, just guessing really.
Edited by spitfire4v8 on Tuesday 7th August 15:30
spitfire4v8 said:
I don't know how the new emerald rollers compare to my dyno, but the old emerald rollers were slightly lower than mine, and mine are slightly lower than surrey.
I think all we are proving here is that different dynos read differently.
A good mapped 4.5 on long pipes makes 390 (ish) on my dyno. In fact I've had loads make 391 for some strange reason (I can't imagine it's the consistency of TVR's builds!)
On that basis you're a good 10 percent down all the way through the rev range on where you *should* be .. but maybe the new emerald dyno is say 5 percent down and John mapped it another 5 percent safe. Or maybe everyone else is high. For the work you've put in you'd hope it was a good 'un.
If you fancy a run oop norf I'd run your car up for free just to see how we compare. And you can tell me about that Stag you restored
edited to add : just seen it was 2016, thought it was a recent run .. I can't remember when the new emerald rollers went in but if it's the old set then yes it'd read slightly higher on my dyno, but 30hp higher? maybe not, but could be 375 or so, just guessing really.
Thanks!I think all we are proving here is that different dynos read differently.
A good mapped 4.5 on long pipes makes 390 (ish) on my dyno. In fact I've had loads make 391 for some strange reason (I can't imagine it's the consistency of TVR's builds!)
On that basis you're a good 10 percent down all the way through the rev range on where you *should* be .. but maybe the new emerald dyno is say 5 percent down and John mapped it another 5 percent safe. Or maybe everyone else is high. For the work you've put in you'd hope it was a good 'un.
If you fancy a run oop norf I'd run your car up for free just to see how we compare. And you can tell me about that Stag you restored
edited to add : just seen it was 2016, thought it was a recent run .. I can't remember when the new emerald rollers went in but if it's the old set then yes it'd read slightly higher on my dyno, but 30hp higher? maybe not, but could be 375 or so, just guessing really.
Edited by spitfire4v8 on Tuesday 7th August 15:30
It was running your short pipes on the Emerald rollers incase you missed that.
The stag is still being done, the owner was so impressed with what I done he’s decided he wants a full restoration now, luckily he’s not bother how long it takes, I keep getting distracted by other things!
I was thinking about coming to you for at least a bit of a remap anyway. I had just mentioned to my other half it needs to go to Joolz really & she said “oh do you mean trackcar? I remember him! Yes good idea”
Regardless of whether I changed the cam timing I think it really needs some part throttle work. I reworked the butterflys after Dave Walker casually mentioned TVR got them wrong, I had one of those Doh palm of hand on forehead moments. PPC never did run the feature on it, I think Will forgot! So I wanted to show you what I’d done. I was hoping the adaptives would correct everything for me, they have corrected the fuelling but I think the timing still needs some work now. It still doesn’t feel quite right. I think I’ve got rid of that 2k hesitation though
You don’t happen to be coming to the TVRCC track day at Rockingham in a few weeks do you?
I’m not so bothered about exact power figures from each RR, I just wanted to compare the curves really.
But yes it was not long after Dave had his new roller installed (you can see the single big roller in the picture with the flames - if the pictures are working properly). The cell was quite hot by the time it was power run time. As you said all kinds of things affect the head line figures but it still seemed a little low.
spitfire4v8 said:
I don't know how the new emerald rollers compare to my dyno, but the old emerald rollers were slightly lower than mine, and mine are slightly lower than surrey.
I think all we are proving here is that different dynos read differently.
Which is why its important to use the same rollers by the same person to compare results.I think all we are proving here is that different dynos read differently.
The most telling is usually on a rolling road day when all cars use the same rollers.
I must get mine retested after the rebuild as it's still got all the work done by Joolz included.
Byker28i said:
Which is why its important to use the same rollers by the same person to compare results.
The most telling is usually on a rolling road day when all cars use the same rollers.
In an ideal world yes, but when there is 11 years between the first & last run it’s not quite that simple The most telling is usually on a rolling road day when all cars use the same rollers.
As I said the first was on a PH organised day, there were a couple of other Cerbs & it wasn’t far behind them on that day, most people (including us) were totally stock in 2005.
SRR moved since that first run, Dave Walker changed his rollers a few years ago, so it’s not always possible. I don’t think Joolz had his own back then, I think he actually came down to use SRR? Austec are long gone, not that I would have ever gone back there again...
As I said I just wanted to compare the curves really. The Austec one showed the power was really dropping off at the top end, not much more than a year after the first run regardless of the actual power figure. It did get used very hard & often back then, I was just about still in my 20s! It was still completely stock for the Austec run apart from my jubilee clamps as pictured.
I should really go to Joolz for just a power run, then go back again with the cams set even for a full remap, shame he’s a 4 hour round trip away! I guess that’s probably the same with him for most people though.
Byker28i said:
SRR are near Farnborough airport now aren't they?
I’m not sure where they are now, it must be about 7 years ago I took my 200sx & it was out that side of London I don’t remember it being quite so far out but it was along time ago. They were inside some kind of secure compound that time. A very different place to the PH day from 2005 that I think was in a normal industrial estate I think within the M25. I’m holding off doing anything to the Cerb at the moment as its suddenly become our main dependable and reliable car, the old E39 BM just refuses to get mended, every time I fix one thing something else goes wrong! For the 4th time in the last few weeks the Cerb has been called upon, my better half just had to take it on a long trip to the south coast from Shropshire.
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