robski

Ok,

so everyone is disputing the rolling road figures from one place to another.

So why dont we get a few bench tested, get some real figures, and then we can workout whether the scoob does or does not come out about right on a rolling road.

This unfortunately leads to a few more questions tho, like who could do it, how much would it cost etc etc etc

robski

Stef

Mega-Bucks methinks.
Probablty not worth it unless your engine was coming out for other things though.
I presume they can't measure the differences mods make unless they're engine mods (ie. no exhausts) as well, so it seems pointless.

Stef.

robski

Stef,

use your melon.

How many people round here are forking out upto £40 to get a "power reading" of their car?

Yet, as soon as they hear figures they dont want to hear, they say there is something wrong, such as you with your PS posts. Or someone else says they are wrong, because they dont want to see someone else with those figures.

So lets see how much it costs to do it properly. If its thousands then ok forget it, if its in the hundreds, we may be able to sort something out.

robski

JoeyDeacon

robski,

Can't see many people volunteering to have their engine removed just so they can see how much power it has!!

robski

well I would, just about everyone I know who tunes cars would prefer a real number rather than one that would be disputed.

Why is it that most people on here just want to write things off?

As I said, lets try to get some real answers for once. If Subaru say 215BHP, I would bet a lot of money this is going to be a lot closer than the numerous rolling roads that produce 235BHP. They have a get out, they say that specs may change without notice when you purchase a car, so why dont they claim 235!?

Makes me wonder if people dont want the truth, and would prefer the "pub talk" figures?

robski

RobJenks

This web site gives a definitive bench test of the Subaru engine and measures the performance gain of various modifications-worth a read.

Stef

Robski.
You're the melon!
An engine dyno will only show higher figures if you've modded the engine in some way (ecu, bigger turbo, filter, etc). Therefore, there seems little point going to all that trouble unless you've had some serious work done to your engine and it's already out of the car. Trying to then link up your exhaust for each car would be a mare!
What do you then do when you make a mod? Take the engine back out again to get a comparitive figure? Hmmmmmmmm......
Rolling roads may not be the most accurate, but they give a good indication for comparitive purposes.
I'm not moaning becasue my car didn't get expected figures, I was concerned that they weren't consistent with either other dyno's or manufacturers claims.

That site gives some interesting figures though, like a full exhaust giving 29bhp at peak power. Sounds spot on.

Stef.




[This message has been edited by Stef (edited 16 November 2000).]

robski

Stef,

you claim they give a good comparative
yet, they dont seem to show gains from downpipes
There have been claims of "corrupt" power gains

doesnt add up to me

You say that they show the benefits of tuning, so why was your car such a poor performer at PS, as was all/most prodrive cars, yet they ARE better in the real world.

Lobs melon back over fence.... followed by mango...

robski

Mulder

I can't really see the point in it either, fine if like Mike R you have you engine out cos its had some serious mods, but otherwise whats the point?

robski

thats one good link

now with a setup like that
we COULD test all the exhausts etc to see what worked, prodrive CPU etc

only thing that worried me was the intercooler. It mentions/implies at the end of the article that for the street you would want a better one, so how good is the current one?

looks like an AVO sponsored event tho!

looks like front mount may be the way to go!

mulder, they have been and there will be engines out, it happens. The POINT is to get a consistent reliable way of testing these things out.

robski

robski

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R19KET

Bench dyno shoot out, Hmmmmmmmm.

Well, it's engine out, deliver to the dyno, couple of hours set up, etc', etc'. By the time you've finished, the cost would be well in excess of £500 per car.

Then, on top of that, you'd think while it's out......

Like Stef says, if it's coming out for work, getting it mapped on the bench dyno is the best way to go, but then, the owner would be telling us how good the figures were anyway, Right Anders .

Mark.

Stef

Robski.
(Mango coming back over fence, followed by hundreds of madarins! ).
That my boy, is the whole point I'm making.
Using the same dyno on days with similar conditions is useful for checking mods, etc.
My problem arises when the figures for cars with various mods vary hugely in comparison to standard cars on the same dyno. IE, if my car gets x bhp more than a standard car at PTS it should surely get a similarly relative increase anywhere?
Oh, and some d/p's have shown gains on dyno's, my Scorpion one did for example.

Stef.

steve McCulloch

You'll be looking at about minimum £1k

Includes:

Engine out
Transport engine there and back
Special harness for carrying of Engine?
Extra long cable for tuning of ecu on engine
several hrs mapping - say about 6 hrs at £40-£50 per hour
Then theres the engine mappers time
Engine back in

I suspect the above will be in excess of £1k if the engine is not already out and about £1k if it already is

sunilp

Hey, where can i buy some melons and mandarins this time of year?

Hoppy

Sunil, I'm sure Sainsburys sell melons and mandarins, but I don't know how many you'd need to buy to get 10p off per litre. With melons especially, you don't always get the same number to the pound, and I'm not sure what the price around Surrey is these days. Best ask Dave.

Back on topic, it's undeniably true that most of us are fascinated by dyno printouts, but it's also undeniably true that comparisons are extremely hard to make. 1) Comparing different dynos is just not on. 2) Comparing the same dyno at different times can also give wildly different results. (Anyone notice how sharp their car felt today? Crisp, cool air makes such a difference.) 3) The only valid comparisons are made back to back within an hour or two of eachother, with all possible variables kept to a minimum (gearing, operator, colour of underpants etc).

Quite a task, but maybe we could use a bit of Scoobynet power here? If we can raise £1,000 for Children in Need, why not apply our collective strength to this one (watdoyerthink, Simon De Web?)?

Firstly, choose the cars with the mods we all want to know about (not difficult). Get them down to the appointed venue at the same time (not very difficult). Get a small team of mechanics on hand to work on the cars so that direct comparisons between this downpipe and that downpipe, for example, can be made swiftly and accurately. Get someone to pay, like car owners, kit manufacturers, car owners, maybe Evo mag, or car owners (probably quite difficult.)

Is this an idea worth pursuing? If so, if a couple of you other guys will help out, I'll volunteer to coordinate it, including getting a magazine involved.

All those not willing to help, please step backwards.

Hoppy

Pete Croney

There's one in Harlow that Bob Rawle used to map Nicky Grist's awesome 22B and do some development mapping for Anders. There also one near Maldon.

The one near Maldon is Terry Drury Racing and they have all the mountings/looms for Impreza engines. I don't know the name of the one in Harlow, but they are equally well equiped. Bob... can you help?

dowser

I'd certainly be interested in parting with some beer-tokens for the results of a scientific bench-dyno comparison including all the popular mods (induction/exhaust/ecu) on an EU and import car!

You'd only really need the two engines - then just bolt on/plug in the goodies for comparison. I take it the Link uses the standard ECU connectors? What about the Motec?

Quite complicated to do properly though (and be of benefit to many) - each must be tested in isolation, and as part of a package. Hhhmmm - the variations are endless!

Richard

Mike Rainbird

Robski,
The only reason you should want to take a Scooby engine out of it's rightful home is if you were swapping the ECU for a different type (such as MoTec or Pectel). Or you were going internal AND swapping the ECU, other wise the cost would be to high for the comparitive gains. Personally the type of engine that would gain loads from doing this is one such as Firefox's, as his has had every conceivable Scooby modification and a bench dyno session would enable him to get the best out of the engine and experiment to see what effect more / less fuel and ignition would have at each 500 rpm increment.

Pete C,
DTW is the dyno in Harlow, run by Dave Wild. There is also SCS in Peterborough (01733 576 614) and BBR also have a bench dyno.


Steve M is right with regard to the costs. It would be about £1k all in to live map something, which includes labour to remove and reinstall the engine and the dyno / mapping operator's time (but does not include the cost of any replacement ECU or internal work!). Obviously you want some significant gains for an outlay of this type!

Best regards
Mike R

Bob Rawle

DTW are a superb outfit and Dave really knows his stuff, regarding a shootout its aready been done using Nicky's engine, Link v Motec ... nothing in it over the low and mid range, Link was better at high revs. Be interesting to do a standard Sti engine though.
Don't forget though that the bench dyno does not generate a complete road map as minor things like idle and boost/throttle response can only be set up on the road.

Bob Rawle

DTW are a superb outfit and Dave really knows his stuff, regarding a shootout its aready been done using Nicky's engine, Link v Motec ... nothing in it over the low and mid range, Link was better at high revs. Be interesting to do a standard Sti engine though.
Don't forget though that the bench dyno does not generate a complete road map as minor things like idle and boost/throttle response can only be set up on the road.
Once Anders car is back and up to speed again it will be interesting indeed to see what the rolling roads say compared to the bench dyno figures I have for it. Now that will be callibration !!

Stef

Hoppy.
This test is already sorted for early next year!
We have the suppliers, the mechanic, the car and the dyno all sorted.

Stef.

robski

Stef,

where, when, what bits etc?

robski