Russs

Does that mean I don't get to tag along and embarrass a few people this time?!

foz01

would be interested in an airfield day

adam too possibly???

john banks

Rollers and airfield please Pete if still space for me

john banks

I think I'll need to reconsider.... having fiddled about a bit with the car, I can't get it surge and det free at sensible temperatures to get a representative run as it would on the road. Simulating the Star run up time by holding it on the brakes (which makes it the equivalent of 10th gear if I had one) I would have to run 4 PSI lower to stop it surging and also pull back a load of timing to stop it detting. So I don't think there is any point in running.

T-uk

JB could you not tell jim how you want your car run on the rollers to solve these problems. you seemed happy with the runs you had at at PE last year, what where the main differences?

I have to say that I think the run at star is far too long, especially for the cooling used. the car is under too much load for too long, run time needs to be halved. thats the main reason I do not do the rolling road days anymore with my own car, they are a good day but far too hard on the car, worse for top mounts which will be detting like mad on the long run. I did two days, one to see if my car (MY00) was gutless compared to the earlier cars, and one with the full exhaust and booster but after watching the knocklink I decided not to do anymore(these were the standard safe retarded/rich MY00 maps).

as said they are a good "crack" these days and good for a comparison as everyone has the same run issues involved.

[Edited by T-uk - 5/17/2003 11:14:05 AM]

[Edited by T-uk - 5/17/2003 11:15:57 AM]

john banks

It seems that several cars with remapped ECUs (either Ecutek or Link or whatever doesn't matter) det lightly on the rollers when they don't on the road or even the track. Previous charge temperatures have reached 88C, although the cooling has been improved since, there is a big issue of load on more powerful cars.

The issue is run up time. A powerful car can get through a gear so much quicker on the road - the run up time is fixed, and suits a standard car far better. So the load is put much higher for the more powerful cars to get the same run up time. This makes these high boosting and on-edge tuned cars run massive internal losses and I think risks serious engine damage. You end up detuning them for the rollers or risk blowing up.

If you shorten the run time by using a fixed load the accuracy on these rolling roads (according to a designer of rolling roads that I spoke to) goes down dramatically because there isn't the processing power/resolution to calculate quickly enough.

I just don't like the idea of my engine (even though I am replacing it soon) which runs right on the edge and very well as you saw the other day being subjected to such high loads. Given that my cars seems to pull about 0.55g at peak torque in 3rd gear yet the run time is 3 1/2 times longer on the rollers than the road then it is like climbing a hill with a downward force of 0.4g (can't remember the trig to work out the angle). Most cars would roll down the hill backwards in 3rd gear trying! It would be a steeper hill than exists anywhere on a road in the UK to subject a car to this sort of load.

I was happy with my runs at PE because:

1. The charge temperatures on a standard top mount with TD04 hybrid at 20 PSI reached only 35 C (this is as on the road).
2. The run time was the same as one the road because the loading was more realistic.

Well Lane's run up seems too quick and I think the accuracy suffers as a result.

Yes the crack is great, but it seems pointless to run and risk a perfectly good engine. The possibility of detonation at those sorts of engine loads is plain frightening and you know I am not scared to run a car at high boost

[Edited by john banks - 5/17/2003 11:37:38 AM]

T-uk

that makes sense as most standard cars, regardless of make are accurate at star.

If you shorten the run time by using a fixed load the accuracy on these rolling roads (according to a designer of rolling roads that I spoke to) goes down dramatically because there isn't the processing power/resolution to calculate quickly enough.

So the load is put much higher for the more powerful cars to get the same run up time. This makes these high boosting and on-edge tuned cars run massive internal losses

sounds like there is no way to get accurate figures then while trying to save the car .

2. The run time was the same as one the road because the loading was more realistic

so is it jim that is fixed or his rollers .I do not know much about rolling roads but would say the best run would be the shortest providing no wheel slip occurred.

john banks

The run time has to be that long I gather for accuracy - it is not Jim's fault or operation technique it is the limitations of an old design of rolling road. On a car that accelerates slowly (say in the region 75-300 BHP like most cars would be at Star) it is not so much of a problem. On a car with double factory output for the same duration of time the work done is double. It doesn't matter how efficient your intercooler, that is going to hurt - coolant system too will have massive heat load. I think it is more punishing than Knockhill, but more so to the more powerful cars.

It is slightly tempting to go along with something that runs 8 PSI until 5500 RPM where it switches to 25 PSI until 6500 RPM and drops again

[Edited by john banks - 5/17/2003 1:54:18 PM]

Andy.F

That's why Andy goes to well lane Quick run time, just like 3rd gear on the road it's very easy on the car. Star is like a 7th gear uphill pull for my car
I still think we (JB and myself) should spend some time with Jim (as Jim suggested) and set up the run time for a shorter duration.

If the setting up was done with a standard car or a tuned FMIC car running very low boost, then we could observe any difference in output at the different run times. Jims rollers can overlay the graphs on screen for ease of comparison.

Hamish69

Is there any further developments on a definate date for a RR date at Star? Also, how many cars allowed and which ones? Cheers,

Hamish

john banks

Could be tried but two independent sources suggest the accuracy would be lost from a quicker run. The electronics just can't do the sampling and calculations in time.

teknopete

Hey folks quick update,

Hamish date is to be 01/06/03.
There has been a slight change of plan with times. Apparently the airfield have an open day on that day which means we can`t have it till 17:00 BUT we can have it for as long as we want from 17:00. So there are 3 options for us, these are :

1 Continue with original times (start at 09:00 run 14 cars and leave the airfield for another day)

2 Start the dyno at the original time (09:00) run a lot more cars then proceed to the airfield.

3 Start the dyno a little later (say 10 or 11 am) and run a few more cars on the dyno then proceed to the airfield at 5pm

Let me know what you all wanna do, as I need to get the lists together and allocate run times real soon and confirm the airfield booking if we are gonna need it.

Looking forward to hearing from every1 that wants a run or a blast on the airstrip real soon
Thanks peebs

Pete


BTW why is it EVERY time we do a dyno sesh the SAME old issues are raised? Same old ground is covered time & time again John, you are correct. With a shorter run the data collected would be quantized to such a point that the values given would not be worth the paper they are printed on, due to the data sampling rate. Now can we put this one to bed ? As you and I know the only way the sampling rate can be increased is by the installation of a faster processor in the A-D converter along with more memory for the storage of the additional data, which must be an uneconomical option otherwise the dyno`s would be designed with this as standard (as this is not cheap machinery) or they would be available as a hardware upgrade

L8r
Pete

Andy.F

But Pete, it's my favourite subject used to be more fun when Sam was contributing though

Can you put me down for the rolling road as well as the airfield since I missed Well Lane this weekend.

Later start at Star would be good for me

Andy

ps Is big red getting the boost cranked up ?

Dougster

Pete, I'm up for the airfield.

Ricey's mine.

john banks

Pete, I suppose I got a bit frustrated with the whole thing again as I was trying to work out how I could set up my car to run on the rollers and got nowhere I think the arguments have moved on a little bit from say a year ago though, some of the issues I detail are not the old complaints and I've not seen anyone try to explain why the higher power cars seem to suffer more from inconsistent results. You've never mentioned quantisation error on the ADC before AFAIK, so this is a useful new thought on the topic as far as I am concerned. If we blindly attend and take the numbers as gospel then it is a bit pointless?

[Edited by john banks - 5/17/2003 10:23:09 PM]

teknopete

Andy

I hear u m8

Re big red, tried upping it a liitle (18psi)earlier this week n it felt like the cluch was slipping bloody sti clutches Hopefully I`ll ave all the "bits" on her and it all mapped in time for this 1 though, hey u know the score bud "it`s work in progress" Lookin 4ward 2 seeing what u bin up2 recently

Doug count u r self as on the list

I`ll put a provisional list together on Monday with who`s doin what so get the names down folks.

Pete

moses

im up for it if j banks lets me win by a few car lengths im so so scared

Neil XR

iTrader: (1)

hi pete

up for airfield as well as the rollers

last time on star rollers, 4 weeks later the engine melted piston

john banks

I'll do the airfield and give you a good roasting Moses You just send me a text message when I can go WOT

moses

lol so im not coming then but if u let me win then i will so how about it and if u break the promise im gonna make u go home withour your glasses i will steal them

dougies549

Hi Pete

You know that you can add us to the list as well M8

How's tricks any way M8

Cheers Dougie

Rob D

Pete,

Just the dyno for me mate, anytime will be fine.

Andy.F

Pete, with respect mate I think this is unlikely to be the situation.

Jims rollers were considered state of the art only 3-4 years ago. I can't believe that such an expensive (very) bit of kit would have a slow processor in it. Even my £150 AP22 can log at 100Hz and store IRO 2 minutes worth. Most processors are rated in MIPS so recording something as slow as 6 inputs from a 15 second dyno run is kids play. Even basic ADC's are unlikely to hold back the input for more than .01 of a second.

I think the inaccuracy introduced by holding back a powerful car and 'roasting' it will be of far more significance.

Remember, these rollers have the ability to control a standing start 0 - 60 mph run whilst simulating 'on road' loads dependant on weight input. This type of closed loop control is not possible without decent processing power. From what I seen of Dave Browns 4.1 second run, it was fully controlled and it also gave a power readout despite the short duration of the run.

The work Sam done with Jim last year was a step forward, I just thought we could improve further.

Instead of polluting your thread any further, I'll copy this into Drivetrain and see if there is any more info available.

cheers

Andy

Robertio

iTrader: (1)

Pete, doesn't look like there will be any point in me running my car, the guy who is making the exhaust has suffered a heart attack, so it is likely to be some time before my car is back to full health.

Given the difficulty I had in trying to stay with any other RX-7 on Castle Combe yesterday my car is putting out even less power than it was on my last run very frustrating when it was a lot quicker in the corners.

Hamish69

I'm up for a RR session primarily but would also like another blast down the airfield. I don't care how it's organised in terms of start times etc, as long as I get a shot on the rollers! Would there be any chance of some timing equipment at the airfield, even if it's very basic? Cheers,

Hamish

[Edited by Hamish69 - 5/18/2003 8:17:14 PM]

teknopete

1st up peebs,

Got a call 2day from Jim, after all the fuss n bover the airfield is a non starter for that day as they have an open day on and it doesn`t finish till 19:00 Now why did`nt they tell us that a month ago [img]images/smilies/mad.gif[/img] Anyway lookin on the positive side that means we can run more cars on the dyno.

So we`re lookin at around 25(ish) motas now for the dyno

The list I`ve got up2 now for the dyno is :
1 Gordon Shek
2 AlanG
3 Hamish
4 Dougies549
5 AndyF
6 John Banks
7 Garry @ yeti
8 Garry @ yeti
9 Dek
10 KevPerth
11 Swany
12 Ricey
13 Wuz
14 Miles
15 Blowses (sorry type there ) Moses
16 Langy
17 Evo7 Barry
18 Bee
19 Rob D
20 Carl Davey
21 Johney 50
22 New to scoob
23 Boyakasha
24 Neil XR
25 Robin M

Could all the above send me some details of car type / expected power / reg no. (this is for tying up pix IN WHICH THE REG NO. WILL BE BLANKED OUT with graphs only) the
rest of details are for arranging the running order.
*** PLEASE NOTE THE NUMBERS ABOVE ARE NOT THE RUNNING ORDER< THIS WILL BE GIVEN ONCE ALL DETAILS ARE COLLATED & NEARER THE TIME ***

If anyone is on the list that wants removed please advise soonest,
alternatively if anyones not on the list that wants to be lemme know asap.

BTW votes for burger van / BBQ ??? (An if it`s BBQ 1 of u buggers can cook it this time )

Thanks again folks

Pete

[Edited by teknopete - 5/22/2003 5:40:45 PM]

[Edited by teknopete - 5/24/2003 1:55:29 PM]

Bee

YGM Pete.

- Bee

teknopete

BTTT

C`mon folks, still w8ing 4 loads of info / details from u In order to run all the said cars this things gonna have 2 go like clockwork i.e. times all allocated details logged b 4 runs etc. So lets get the info together eh ?

BTW thanks Bee (he who sent required info)

L8r
Pete

GordonShek

Teknopete

Am I too late?

Scooby Dooby Blue

YHM Pete