Well, we had the first northern RX RR Day today, but it could be said things didn\'t got too well.
Started off with 3 FDs (spectacular turn out) of which Bobs mustered IIRC 159bhp due to the second turbo not playing ball (fine on the road, not on the rollers). Gavins stock Type-R (bar backbox) got 233bhp, huge drop off at transition - even more extreme than when I had my dead cat.
And mine, well my quest to turn it into a turbo diesel is progressing well ;) I have succesfully decreased top end power, while increasing torque.
279bhp (226.5 wheels), 249lb/ft
Just looks like a more exagerated version of my last run at Star - everything is going fine until 5-5.5k rpm then boost decides it has had enough and torque drops off, leaving power fighting a battle it was never going to win.
Boost was higher than last time I ran at Star, and all that has happened is the intercooler has overcooked itself earlier in the run. One of those times where more boost (0.85 vs 0.7) = less power.
I know I need to get the intercooler on, just need to find a way of making it fit. One day, oh one day I will get decent figures from these rollers.
Try a spot of WI injection Roberto that\'ll cool the ACTs right down:cool and will hopefully keep your bhp going up way past 5,500 rpm:bandit
Still a nice bit of power though:D
Regards,
Paul:)
I have to admit I am a bit gutted at the poor show I put on. But I never realised they didn\'t just floor the acelerator when they did a power run on these rollers. If they had the secondary would have spooled up no probs.
I thought for a power run you would just floor it, but it seems they accelerate as they watch the graph... which does strike me as odd.. especially when it is not a mapping run. This was the first time I have ever had a car on the rollers, so I am probably wrong.
The graph is going to live on my fridge with a note "Must Do Better" so that when I open the fridge I realise why there is no food in it.:rolleyes:
they wont just floor it as they are watch the af readings and graph, if they see a major problem with your car its easy to ease off and save your engine, rather than rev the nutts out of it and when it goes bang "sorry" plus the graph drawn is much more readable giving better information.
QuoteOriginally posted by bobster
The graph is going to live on my fridge with a note "Must Do Better" so that when I open the fridge I realise why there is no food in it.:rolleyes:
A fridge? you don\'t need one of those if you don\'t have any food - sell it and make better use of the money :p
Thanks Paul, it is on the shopping list (had originally planned to have WI fitted before Spa last year). A shame this run was the second lowest figure of my 7 RR runs in the last 10 months, roll on the bigger numbers :)
The fridge won\'t be plugged in. It\'s just an \'All show and no go\' accesory. Like the skyline that put as all to shame.
QuoteI have to admit I am a bit gutted at the poor show I put on. But I never realised they didn\'t just floor the acelerator when they did a power run on these rollers. If they had the secondary would have spooled up no probs
We have this problem with RR days in our club (RTOC), there seems to be a serious inconstintancy in the way different rolling road establishments use their equipment and resultantly what figures they obtain. I know that the fueling etc needs to be monitered but that can be done in the set up before the main power run surely?
I went on 3 separate days to 2 different rolling roads within 2 consecutive weeks with my 5GTT. The first two were at John Nobles and the last was at Europarts in stoke. The first time i got 144bhp, but my fueling just died due to a worn out fuel pump so the peak power bhp was at a lowly but impressive 4500rpm and the torque was well over 180lb/ft at 18psi of boost. So i went home went to a scrappy and picked up an e30bmw efi bosch fuel pump for a fiver;), put it on, did some fast road testing and all was good the car pulled well into the 6k region in all gears. So i went back to nobles and had my car set up, well to be honest i don\'t really think the guy had a clue about carbed turbo cars (guess they\'re quite rare??) so he did a comp test, set the idle co and part throttle co and then did a power run after putting my leads back on the wrong way round and trying to guess it right again for 20mins until i eventually climbed over the silly barrier they put up to stop peeps getting in the way so to tell him where they should go:rolleyes: Anyway back to the story he ran the car as you described holding the revs and climbing slowly up, the graph came up and i only got 155bhp@18psi (5500rpm) and the nice print out graph stoped at 4500rpm again for some random reason because the comp thought it was finished as I think it got wheel spin there, which the guy didnt detect:reallymad so i wasn\'t best pleased and decided that was it and paid the 75quid that basically all i got back was my CO setting up:(
Anyway a week later I ran the car at the Europarts RR day, a 5 tuner in stoke, and he does power runs by just booting the car from about 3000rpm right up to the peak power and low and behold i managed to get 220bhp and a massive 240lb/ft of torque:cool and i changed nothing on the car what so ever.
Now to conclude the feeling i have was that the main RR guy at Nobles was away and so i had someone who wasn\'t quite clued up as they should of been operating the rollers so to be fair Nobles should be good as they have the right equipment, but no the knwledge as far as i can see, and secondly i think the little 1.4 pushrod gtt engine needs to be really going in order to get the big hybrind turbo\'s flowing properly otherwise they won\'t be upto speed to flow properly and this may also be the case for the rx???. This difference between the two rr day results was seen on many peoples fives that atteneded both RR days. And i also know that RR arn\'t 100% accurate, but still there shouldnt be that much variability????????
Ok sorry for the long post but just trying to show another RR experience for a different car.
Regards, Paul:)
Just checked back and Robbie made 312 fly about 2 weeks ago on a different set of rollers at Dastek. Once again different setup and different technique as far as Im aware. As oposed to 279 fly on the Star rollers. The cooling at Dastek was unreal compared to Star, infact probably closer to what you would get driving on the open road. Hence lower intake temps.
I know the lower charge temps would make for more power but surely a difference of 30bhp is odd. I know different roller setups would give different results, but probably technique would contribute too.
Oh and another thing. None of the FD\'s saw an exhaust probe on the star rollers.
QuoteOriginally posted by bobster
Just checked back and Robbie made 312 fly about 2 weeks ago on a different set of rollers at Dastek. Once again different setup and different technique as far as Im aware. As oposed to 279 fly on the Star rollers. The cooling at Dastek was unreal compared to Star, infact probably closer to what you would get driving on the open road. Hence lower intake temps.
I know the lower charge temps would make for more power but surely a difference of 30bhp is odd. I know different roller setups would give different results, but probably technique would contribute too.
Oh and another thing. None of the FD\'s saw an exhaust probe on the star rollers.
Hmmm so Star doesn\'t sound like the best place to go, unless you really want to blow your car up:eek: ;) I can\'t believe they didn\'t even monitor the fueling via a CO reading:rolleyes: Charge temps could alter the reading by upto 10% i would say, but is doubtful unless the temp difference was really significant and that there was extra fuel present for the increase in oxygen content due to the higher density of the cooler air. So the temp difference alone could explain the difference in power figures, but more than likely a combination of variables will account for it i.e. calibration errors of the rolling road, user errors, caluclation differences in converting from wheel figures to the flywheel, frictional values of the rollers, ambient temp, different approach to recording the power run, octane rating of petrol used, etc etc etc etc.
At least we can say that it is a massive grey area and that they are good for sorting the fueling out and seeing if new mods have made a difference to power as long as you use the same rolling road again and again. Unless of course you can afford to take your eninge out and use a proper engine dyno:rolleyes:
Regards,
Paul:)
The run at Datsek made 260rwhp and somewhere over 312fly (312 was used as that was the highest value at one of the 500rpm increments that was displayed on the graph - saw 316 on the screen during the second run and the 2 later runs were higher). Didn\'t say anything on the day as they were still working on the output and all the cars were done the same way. That was with the dropping boost at high rpm problem as well, just it hung on to the boost for a bit longer there. I was also running a less agressive map at Dastek than Star.
At Star it was the main guy who did our runs, so you can be sure he knows how his rollers work (likewise we had the main guy at Dastek). He probably figured it wasn\'t worth running the AFRs on our cars as he wouldn\'t know the safe range for rotaries and my car left one of his members of staff crying last time he put his head in line with my exhaust :o (for some reason he felt my car was running a little rich ;) ) They started monitoring the fueling on the 200s after Brian\'s car started detting like mad top end, and he didn\'t want to kill any engines. By the time you have done as many RR sessions as Jim detonation becomes something that doesn\'t need a guage.
Temps were hugely different between the 2 setups, my air temps were 23 degrees lower at Dastek. Other than that and my map (which I believe would have made 320-330 at Dastek) my car was in exactly the same spec from type of oil, fuel and octane booster to tyre pressures. Ambients were similar both days - snow and ice outside.
When I was speaking with Jim during and after my run he said I\'d have made 300+ if my temps had stayed at sensible levels. I would say that Dastek reads 3-5% higher than Star, but on turbo\'d cars the cooling has a large part to play.
I\'ve used Star for quite a few years and have faith in their fly bhp being accurate, cooling has always been adequate if nothing more which results in cars running FMIC getting higher figures than the same car would with a different intercooler. One 80mph fan and 2 x 40mph fans just aren\'t enough with a SMIC FD.
Hi Robbie,
gutted that there was only 3 cars there, I take it Angus was unable to make it in the end (Due to the snow im sure)
I can only hope you want to organise this sort of thig again in say the summer or next year. I will be there (Hopefully I won\'t breck any bone the week before though :) ) Im gutted I missed it!
I should be back in my car sooner than I thought though as I had to have an operation on my leg which should mean the cast will be off in 6 weeks and not 9.
I do hope there is something done up in Scotland this year that I can make it too.
Cheers
Steve
hi steve
i think were wanting to meet at crail in april(8th i think) i think theres 3 or 4 at the moment.
hope your legs better and you can make it and show the 2.0l novas:D
rik
its the 18th
heres the page
http://www.mazdarotaryclub.com/forums/showthread.php?s=&threadid=4022
rik