Its seems that a post has been deleted from the owner of the rolling road which slotted in between my last post & the one by AP !

 

how did the foresters do?

 

The one about fan size?!?!?

 

yup

 

I deleted the message becuase I catagoricaly stated that i was not going to be drawn into a discussion on the boards. I was trying to be friendly and helpful. Not sure why i bothered now.

 

Seems like you are trying to hide something to me !

Why not be honest & open ! As you know I have sent you a PM & would appreciate a reply !

 

I have replied, but you're mailbox is full!

I have nothing to hide, feel free to slag off my rolling road as much as you want.

 

My in box is no longer full !

I havent slagged off your rolling road, I have just asked some questions which both I & others would like some answers to !

You have admitted already that the fans were inadequate ! All I am asking you to do is clarify some points ! Surely if you want us & others to use your rollers again then it would be in your best interests to be open with paying customers.

Thanks

Paul

 

IIRC Dyneys car made 303 at the hants RR at the same place so either hes been tweaking or the rollers are inconsistant

 

That was at PE, not on our rollers.

 

And i said i would, but not on the boards.

 

and he had a very floppy wastegate & 6k rev limit @ PE, so yes, it's had some tweaking.

 

Vixpy1 I look forward to your PM !

 

my apologies i thought it was at PE ill shut up then.Would still be nice to see a list of results tho

 

I got 109bhp at the wheels (no flywheel figure given as my car is an automatic)

As standard the Forester S Turbo is 174bhp, so that gives about 38% transmission losses.

Then again on the rollers the car was only boosting to 0.45 bar, where as it makes 0.5-0.55 bar on the road.

I was expecting the bhp to be slightly down as the engine has 100k on the clock, so pretty close to what I was expecting.

SteveM made 178bhp (whp)/233bhp (fly) and missed the boost target by 1psi.

 

Andy,

Thanks for organising the RR day Sat. As it was my first one, I was nervous seeing the car being revved for the first time but once it was off the rollers in once piece, I was fine! Good to meet other JDM wagon drivers too and some of the Surrey Scoobs.

Sounds like most/all cars were running 25-30 bhp down on what they were expecting. Doesnt bother me too much as I *know* my car is running rich Incidentally were there any standard Scoobs running?

SMG: 573 bhp. JFC -

 

Even Tim's car running without nitrous made 412bhp!!!

 

so mixed feelings about the outcome on the day then? sounds like all had fun thoe

 

Fulham, Keep it off the thread!


I think the rollers were reading conservative, but then who's says that other rollers are right This is a brand new set up, running factory settings!!


I had 303bhp at PE about a month ago (with the wastegate slightly open and a 6k rev limit. To control the boost)
I made 323 bhp on Sat But I expect I would have made 350 on PE's rollers If it had been Well lane who knows Which one is more accurate??

Rolling road figures can only be compared if the car is run on the same rollers on the same day!! Shoot out days are a bit of fun, no more.

As for all the cars running rich! That's not quite true


I had a great day.
Thanks to Andy, Charlie and all involved. Couldn't even complain about the price

 

Gents,

it is well known that the Dyno Dynamics rolling roads read lower than Power Engineering, but they are at least consistent amongst installations of the same type. Harvey was kind enough to make a 300 mile round trip to do a back to back comparison between Scooby Clinic and G-Force, on the same day, with the same car, and the same map, even the same tank of fuel, but two different venues. What we found was a discrepancy of 1.5% between the two installations in power, but a bigger discrepancy in terms of torque, but I think we have identified the cause and after correcting for that, we were again consistent to less than 1%.

If someone were to take their car to Power Station then they could also expect lower figures than they would find at Power Engineering. Same would be true for Engine Advantages. It's difficult to know who is actually "right", one would have to remove the engine from the car and test it on a bench dynomometer to find the true flywheel figure.

People are free to believe whatever figure they want to. The key to using rolling roads effectively in evaluating the effects of modifications is to choose one set of rollers and stick to them, so long as they are consistent. Rolling road days are a bit of fun, comparing figures between cars on the same rollers on the same day...

As for the cars running rich, it's basically a case of "it's a Subaru, they all do that!" The engine design does not lend itself well to running the leaner AFRs you might expect to see in other performance engines such as Cosworth YB. There is some benefit to be had from taking a controlled amount of fuel back out, but it's a delicate balancing act, while the overall AFR of the engine may stay "sane", that is no guarantee that every cylinder is getting a sufficiently rich charge, such is the design of the engine.

Cheers,

Pat.

 

Pat you should be aware that Merv took a car that had been Teked on the PE rollers straight up to G Force imediately and 45 mins or so later it ran less than a 5 bhp difference so that would imply G Force and PE are very close. I fail to see the relevence to this thread of the G Force and Clinic comparison, you yourself have shown how things could get distorted. It is good to hear that at least those two rollers will be comparable though.

Having looked at some graphs and seen some figs there does seem to have been some disparity here for whatever reason.

General comment, rich is a word used to describe a lower than normal afr in a car, however depending on the car the same afr could also be considered lean, 10.9 is considered normal in remapped cars in some quarters although to me that would be rich. Engine/model year plays a huge part with GC8 engines being capable of supporting leaner mixtures than new age of course.

Someone put a post up asking about a dip in his power curve and he ran at this rr day, the dip is probably caused by the engine choking on too much fuel which could also explain the poor power figure, excessive heat soak could cause that as the factory ecu pulls timing out it also enrichens.

Finally there is no way anyone should relate figures on one rolling road to another, most will yield differing results dependant on setup and operator skill. Find one you like and stick to it for comparative benchmarking only is my advice.

I did read the post relating to fans now removed, considering the criticality of proper cooling to these cars that defo needs sorting to the level used by G Force who have a superb setup imho, PE also have large powerful fans and Harvey mentioned he thought the Clinic fan a good air mover as well. Not only can it make the difference to being close to on the road relative performance but engine safety as well.

cheers

bob

 

My comment on the fans related to Intake Temp only. Our fans are quite capable of cooling the cars, and also of cooling the front mount intercoolers. We chuck 15,000 cfm at the cars. However some of the cars DID run high intake temps and this is the reason I have invested in a G-force fan, which has more air speed. However our road runs a live atmos system and corrected for the intake temps on the day. The comment was miscontrued and hence i removed it.

The SMG car ran 10bhp at the wheels (462 vs 452) more on Sat than after mapping on Tues. Probably due to the fact that we ran it in Shootout mode on Sat as opposed to a straight ramp while mapping. We did not run a flywheel graph on the Tues!. This is despite it being much cooler while we mapped it.

PE and the Dyno Dynamics rolling roads read very close at the wheels, however there is some difference in the flywheel estimations. My own Legacy has run the same wheel figs on both roads when it was Standard. It is Decatted and runs 300bhp at the fly on my road. The standard Bugeyes all ran the same figs on Sat as they have on Scoobyclincs road, almost to the HP, this indicates to me that all the Dyno Dynamics roads read the same.

On our road, a 911 GT3 will come out almost to the HP at the fly To Porsches own figs.

You are of coarse free to come down and inspect our road for yourself Bob. Please feel free to email me with any questions you have.

Cheers,

Charlie Wright.
Managing Director.
Surrey Rolling Road.

charlie@surreyrollingroad.co.uk

 

Nice to meet some of you guys on the Saturday. Was a great day out! Shame it was a little warm for the cars. Ran 242bhp fly 163 bhp wheels and 200 ftlb.

 

Seems pretty conclusive to me !

Ran on the PE rollers today & made a considerable amount more torque & BHP than on the Surrey Rolling Road on Saturday !

This roller has been rolling Clio 172 s at 172 bhp & Focus ST170s at 170 bhp ! So their rollers appear pretty accurate to me !

 

A considerable amount eh?

Would you be willing to publish the wheel figs then?

 

I would say 10% is a considerable amount ! Im my opinion this must be due to user error rather than just temp etc !

 

you can't compare flywheel figs on teh two roads. So what was the wheels fig?

 

Charlie thanks for the offer, I don't inspect rolling roads but I do like to drag my car around them to see what it's doing from time to time.

BTW, shoot_44 is a setup for the wrx and in Oz should be run in 3rd gear according to some interesting info I came across on 22B, so what effect would that have on a wrx that was run in 4th gear ? Thats based on Dyno Dynamics own recommendations iirc.

Maybe the issue was gearing ?

as a thought

cheers

bob

 

Hi Bob,

Your welcome anytime

The gearing is a huge debate in itself to be honest. I have done tests in my own Legacy with a 5 speed box, The car generated 2 more bhp in 4th at the wheels. There are arguments that the closer to 1:1, then the lower the transmission losses. Certain cars, (The old corvettes for instance) are HUGELY fussy about the gear they are run in. Other cars, 200SX for instance, it does'nt seem to make a blind bit of difference. Fiat coupes Turbo's will give more power in 3rd.

We tend to stick to 4th for most cars. I think the key is consistancy, Running the same cars in the same gear everytime they visit the road.

Cheers.

Charlie.

 

Clio and focus quote PS don't they? Told you PE over-read!