My day out comparing chassis dyno's....

[boXXer]

After Sundays RR day @ Torque of the Devil, and all the talk about how peoples figures were low/wrong, it got me thinking about how chassis dyno's compare to actual engine dyno's, and how the figures are so different between them.

 

After speaking to Steve Curson @ Vulcan Engineering, we came to the decision that it would be good to compare the most popular companies that people use, and their Dyno's just to see if they were THAT much different.

 

So, on my day off this week, instead of staying in as the weather is SHITE and playing on my XBOX, or in fact, playing with myself, i decided i'd drive around and test a few dyno's out, just to see whos were most accurate to my engine dyno session.

 

 

These were the results.....

 

Here is a video of my 2.1 Pinto, being dyno'd by Steve and Aaron @ HT Racing.

 

 

if you watch it until the end, the power graph comes up, and it made 187.7bhp @ 7100 rpm and 158.3lbs torque @ 5400 rpm, so this was my ball park figure to compare with.

 

 

 

 

This is the first power run i have of the car, from Torque of the devil on Sunday,

 

 

It made 174.9hp and 142lbs of torque. PERSONALLY, i think the dyno there does under read (no offence intended Chris!), regardless of what anyone says. This can be a good thing though, as it makes you chase more power!

 

 

 

 

Anyway, my first stop yesterday was to a local place by me, called "motorworx". Now, the dyno there is EXACTLY the same as Chris' @ TOTD, and about the same age too. They ran my car up and these were the results from those guys.

 

 

It made 180.8hp and 145lbs torque. Again, IMO, its slightly less than what it should be. Now, i did notice the intake temp was higher, and i understand this gives a slightly higher power reading over the one @ TOTD. So maybe they were exactly the same?

 

 

 

My second visit was to Sanspeed, in bexley heath. Now, it has to be noted that the Bosch machine he had there, is about 2,000,000 years old, but looks cool as Fook! Even has a oscilloscope which is a pretty handy tool! The graph it puts out is mega basic, and doesnt have a torque figure which is a kick in the nuts, but does give a power output. This is what it came up with...

 

 

186hp @ the fly and 163 @ the wheels! Note that the power is in KW, and was converted to hp. Almost spot on, and for a seriously old machine, it rocked! i was impressed! Shame it couldnt give a torque figure though.

 

 

 

 

Last place to visit was Track n Road, in Essex. They use a TAT dyno system there. Now, these guys map loads of cars (gt 40's, ferraris etc), and do a lot of development work for ford, so i assumed that their rollers would be pretty much spot on. So, on went my car, and a power run was done...

 

 

Came out as 186.5hp, and 157.2lbs. Again, i would say absolutely spot on, seeing as the engine is now in a car, with a complete exhaust system on it.

 

So, to me, it does seem the the dyno dynamics systems do underead just a tad but i believe they calculate power in a different way to other systems.

 

Was a long day (started at 8am and got back home at 9pm), but was well worth it.

 

Now, this is obviously all based on my particular engine, so please comment, but dont come up with clever, bollox, comments as its a pain in the arse.

 

Mike

[Rick]

excellent work mate. did you have to pay for all those sessions though?

[kevmk2]

Interesting stuff,so my old favorite sanspeed still come up trumps

Pity you couldnt of gone to Paul hills too,but thats even more of a trek

I would like to know how much they charged,as i would like to see what my engine makes now with 2 bar of boost. It was 438bhp with 1.4bar

[RETRO_AL]

Very interesting,gaz always said track and road undereads

[sambo]

I like it! Well done that man.

 

It was interesting to see how the older machine read. Where i get my car rolling roaded, he uses an antique and i was a little concerned as to its accuracy, but it is proved that even if its old, it doesnt mean its inaccurate.

 

Good test Boxxer! A day well spent!!

[Mk2Jo]

Well done What an excellent set of figures for comparison

[boXXer]

Interesting stuff,so my old favorite sanspeed still come up trumps

Pity you couldnt of gone to Paul hills too,but thats even more of a trek

I would like to know how much they charged,as i would like to see what my engine makes now with 2 bar of boost. It was 438bhp with 1.4bar

 

TBH mate, everyone knows Engine advantages rollers over-read. bit like powers do! i managed to get 310hp on yellows there.

[Guest gone]

Well done bud you certainly have done your homework great stuff

[4parajon]

You must have more money than sense Mike, must be that spikey hair

Seriously, interesting reading that

[boXXer]

excellent work mate. did you have to pay for all those sessions though?

 

Hiya mate. I didnt pay for anything! (apart from my foodings, and i paid for the motorworx run). Steve @ Vulcans put his money where his mouth is, and paid for it all. Good bloke he is, how many engine builders would do that? Just shows he aint got nothing to hide IMO.

[boXXer]

You must have more money than sense Mike, must be that spikey hair

Seriously, interesting reading that

 

as above mate. I dont wanna take ALL the credit, as Steve helped me out a lot.

[mk2dk]

Hi boxxer

That must have been an interesting day off Was our car strapped to the rolling road in the exactly same way ? Ex. pulled back and down on the rollers or just pulled down. This can also change the readings very much. What I meen is, same operator on different RR ort to give almost indentical readings.

[Guest MK1gaz]

Top work mate . Nice to see that Track n Road is reading higher than Sanspeed as usual

[Guest MK1gaz]

Very interesting,gaz always said track and road undereads

more like overeads , too many big bhp x-flows on it

[boXXer]

Top work mate . Nice to see that Track n Road is reading higher than Sanspeed as usual

 

by .5 bhp! amazing difference! at the end of the day, my engine made 188 on a dyno, and 186 on T n R's rollers. thats MORE than close enough for me!

[Guest MK1gaz]

My old Harris pinto made 185 bhp with 45's and points at Sanspeed so that's the same as H.T.'s dyno as well then . It also made 187 bhp at southern carbs and injection + 175 bhp at power engineering .

[chris@torque of the devil]

well there goes all my customers! :mrgreen: , fair play for doing it fella, not wanting to get all technical but a few things to comment on.

 

our dyno is not the same as motorwork's, similar but ours has twin retarder rear set up, also the intake air temps were higher and the tyre pressures were different, we set all cars at 50 psi on sat for consistency, but only 5 bhp adrift and run on a different day, you should have come back to me for a freebie on the same day., the place that gave you a power figure with no torque figure WTF power is a calculation of torque and speed so why no torque?.

 

thing is who is to say that if it went back on aarons dyno it would still be the same, we will never know i guess, well done for doing the testing though, its nice to see someone making the effort to compare.

 

chris

[Guest MK1gaz]

The most important thing is that Track n Road reads higher than Sanspeed . It's supporters are always slagging off Sanspeed rollers for being too high YET Sanspeeds are actually lower . I told the non-believers on Turbosport this for years so now i'm milking it !!!!!!

[Retromotorsport]

Gaz... post your old sanspeed graph up fo your Pinto ..

[BIG G]

great post well done that man

[Toby]

Very impressed with your dedication mate

 

Well done to Steve for the sponsering too. Top bloke!

 

I feel like popping back to Sanspeeds to see where my power has gone. One thing I wondered on the day was strapping my car onto the road with straps over my rear flexible brake pipes, although Chris doubted it would have any effect.

 

One advantage of the over run system is it highlights problems within the transmission. ie hand brake on - Peter does it almost every time.

 

HOWEVER!! the computer down loads for working out 1/4 mile mph / times I have shown in my readers rides support the accuracy of TOTD.

 

Whatever!! It goes flippin' well!!

 

Still going to do my other head though!!

 

I'll scan my Sanspeed graphs and put them up in my readers rides too.

[Retromotorsport]

Personally i feel Peters had a bit of calibration done.. as the few cars i knew of that went on Peters and T&R , Peters normally worked out 12% over T&R's rollers ..

 

But recently he has been almost bang on the money ..

 

Toby what did your car make at Sanspeed's and what did it make at TOTD ?

[chris@torque of the devil]

what i dont get is stuff like this, we ran a completely stock fiesta ST150 yesterday and it showed 149.7 bhp on my dyno, if that car was run on sanspeeds rollers would it show 161 bhp?, also the wheel figure from sanspeed and track and road is showing as 163 ish and we showed it as 145, huge difference there, i really dont know what to believe, my money is on the track and road dyno being 100% spot on and mine being a load of expensive red and blue shite, i give up and am now going to become a male stripper.

[Toby]

Personally i feel Peters had a bit of calibration done.. as the few cars i knew of that went on Peters and T&R , Peters normally worked out 25% over T&R's rollers ..

 

But recently he has been almost bang on the money ..

 

Toby what did your car make at Sanspeed's and what did it make at TOTD ?

 

Regular 190-194 Sanspeed one 201!!

 

TOTD 162.8

 

See other threads too for my other comments.

 

You may be right if HT have mentioned high readings to Sanspeed, he may have done.

[Guest MK1gaz]

Gaz... post your old sanspeed graph up fo your Pinto ..

I've not got it anymore (my mate Tony's got them all as it's now his engine) so you'll have to copy and paste it from Turbosport as it's on plenty of threads over there .