Shaid

Does anyone have any real performance charts or comparisons between different dynos?

This being where the base car on both dynos being in the same state of tune however the results being different by what you deemed a significant margin?

Let’s say for example you went to Dyno 1 and got 330 bhp atw and a week or so later having made no further modifications to the car went to Dyno 2 and got 340bhp atw.

I’m not asking for naming and shaming but just a share of experiences.

Fonzey

iTrader: (5)

I've been to one dyno twice and got within 1bhp of each test. Went to a third and "lost" 50bhp...

Shaid

Really?

What happened between both dynos any loss in state of tune? Did the car need a service? Was it running or boosting right?

nikon-man

iTrader: (3)

why not put a data logger in the car then you would know exactly what is was doing

just my opinion

Fonzey

iTrader: (5)

No change at all and was running fine.

Went to Dyno A and got 320bhp

Few weeks later went to Dyno B and got 270 and was told it was running really lean.

Went back to Dyno A to troubleshoot and it made 321 without so much as touching the car...

Blue by You

iTrader: (23)

Providing a given dyno is properly maintained, it is the operator that is far more significant in terms of results repeatability than the actual machine itself.
Further complications arise if you use different dynos and operators, you can't tell where you are in that scenario.

bustaMOVEs

iTrader: (31)

If you are way under then the dyno operator is trying to pull your pants down.

Shaun

I have a fair bit.

What were the dyno as in makes?

TonyBurns

iTrader: (3)

Its always best just to measure against 1 dyno as different dyno's can give different readings, so dont take it to heart if one gives you 10bhp more than another on, what you want is consistency and here is an example of that.

My "old" Spec C use to run between 312-316bhp on the same dyno, I sold her and off she went round the country until about 5 years or so later when she ended up back at the original place that I used for the rolling road, she made..... 312bhp, thats what you want, jumping between different makes/places will just confuse you, pick a GOOD place and just use that

Kwik

iTrader: (10)

I put my car on ebay and instantly gained 200BHP.

andy99ppp

iTrader: (2)

And not to state the obvious but surely the weather temperature has to do with what bhp is to be gained? Ie on a cold day it's going to be higher?

LuckyWelshchap

Shud av dun swapz.
Thay do +220 their wivout DV.

brocksta

iTrader: (1)

i agree after ya money.

Shaun

If the dyno is running proper correction, this should not be the case.

JDM_Stig

iTrader: (3)

tyre pressure can really alter readings.

MattyB1983

iTrader: (51)

I know of a car that made 320bhp at srr previously. It then had a front mount fitted and mapped at RCM where it made 320 again. The car was then taken back to srr where it made 345.

Alan Jeffery

Sorry, but I think that's unlikely.
As a dyno operator, I can tell you for sure that there is no basis for telling someone that their car is underpowered if it isn't.
It's about BHP being a BY PRODUCT of correct tuning.
This is how you do it;
Choose and build your spec based on the result you are looking for, taking into account all the factors such as useage, expected lifespan and cost implications.
You then tune the car to suit the brief. Begin with low boost, then set timing and fuelling. Increase boost gradually, setting timing and fuelling as you go.
I'm being simplistic, but that's about it as far as power goes.
Eventually a state of rapture is reached. Or not.
Once you have the boost, timing and fuelling set correctly, bearing in mind the specification, that's it. You can't go anywhere else. It's no good ramping up boost, as it won't flow any more. It's no good adding ignition, as for the spec and fuel used all you'll get is det. Ditto fuelling, it'll just be too lean or rich. It's what tuning is all about, finding BHP is the bonus.
Therefore when you dyno test a car, assuming you are monitoring the management system, you can see what's going on. If you have a "Blah" turbo, and all the parts to go with it, you will expect to (roughly) see a particular set of figures. If you don't see that then SOMETHING IS UP, and you need to investigate.
I would expect an operator to be able to point out what the problem is, assuming there is one.
Only an idiot would say that a car can be improved when it can't. I didn't think there were many of those who'd make the considerable investment in running a dyno.
Dynos give different outputs for all kinds of reasons, but the boost, timing and fuelling characteristics stay with the car, and are the important part.

Blue by You

iTrader: (23)

It would seem to me that anyone making comments about mappers/dyno operators suggesting they are somehow ripping customers off is showing a distinct lack of trust in their chosen tuner.
It begs the question 'Why are you using that tuner in the first place if you don't trust them?' Why wouldn't you trust somebody you are giving your P + J to put through its paces?
The guys I have used to build and tune my car have my absolute trust. It's not because they don't make mistakes (they are human), or perhaps can't acheive what I expect them to. I can't see the point in giving them my car and the investment I have committed in time and money, and then questioning what they have done. The customer/supplier relationship I have with them is sufficient to establish the trust necessary for me to know that they have done the best job they can with the machinery I have given them.
The bottom line I guess is to pick a reputable and trustworthy tuner and be happy with the result.

bustaMOVEs

iTrader: (31)

I understand you que, but my comment was based on 'oh your cars running lean etc, let me fix it and ill get you x amount of hp' comments.
Then when i have gone to the usual dyno and all is fine etc.
I know there are problems in some cases but you need to choose the dyno/garage carefully is all im saying

jayallen

iTrader: (31)

Dyno inaccuracies...... How about the two classics making over 450 on a VF35 in this thread https://www.scoobynet.com/general-te...f35-power.html .....Obviously its true because they were giving an ickle chat that says so.......

...........but where did it all go wrong? Is it just a case of operator error, operator a little to keen to satisfy his paying customers or have we all overlooked the potential of the VF35

just me

iTrader: (3)

The garage I used to use, employed lots of little tricks to artificially give low readings in order to undermine the work of a well known mapper.

They did things like sitting the car for ages with no air flow, probably to heat up the intercooler, do some dummy runs with no fans, probably a few other things, but it was always ended with criticism of the mappers work (they have started mapping themselves).

Cars were always around 30-40bhp down than what they should be.

Shaid

That thread

Shaid

My first and ever rolling road session at Ajec Racing (who eventually were raided by drugs plod and no longer exist) was depressing.

I got 257bhp on my Twin Turbo Legacy GTB which made me really sad.

Maz

iTrader: (34)

There's some thickies about!

Shaun

You need to compare apples with apples. Those two sites use completely different software and it has already been previously noted, that based on some results, the later software appears to provide lower figures (but this could be a combination of software changes, strapping methods and cooling). I ran at both and only found a very minor difference (iirc circa 1.8%).... some have seen greater differences.

From a baseline perspective in the UK, results tend to be very comparable using the Dyno Dynamics set-up at either Surrey Rolling Road, ScoobyClinic and Engine Tuner (they all use the same software). For that very reason (and because of the catchment areas these RR's cover), I would mostly recommend using anyone of these, for comparing figures of set-ups etc.

Tidgy

lol, that thread is epic beyond words

IainMilford

iTrader: (15)

This has some interesting points http://www.pencilgeek.org/2009/09/ex...s-how-the.html

Mick

iTrader: (1)

When I bought my Legacy 2.0GT twin scroll it was advertised as 320bhp... Imagine my surprise when I took it to ProSport RR and found it would only register a peak of just over 240 bhp

These cars run 280 bhp as factory standard and mine had a full MillTek and EcuTEK tune...

With a bit of research I found out that the springs in the wastegate actuator are prone to weakening with age. When I got a replacement part and a map check from Andrew Carr we were back up to 305 bhp - which as you can imagine was a huge relief

So I would say, worth a check every so often just to make sure nothing has gone amiss