The problems of dyno testing

I did try dyno’ing GBMINI#2 last year, and repeated the experiment after the JCW intake was added; the second link has an interesting table comparing GBMINI#2 (rated 210hp by the JCW upgrades) and Greg’s car, with many aftermarket mods. In summary, the comparison is worth something, but open to interpretation.

On this same subject, NAM has had much discussion about a specific air intake from M7, culiminating in some dyno run comparisons.
Commendably, a number of NAM members fronted the dyno costs, to provide good independant data; I was in turn interested enough to send in a few $$$ and get the results.

The results make fascinating reading, if only for the difficulty of comparing one mod with another – even with the efforts made to keep everything at a similar baseline …

Some background on how we did this and the factors we used to try to match each run to get the same date base line for each intake. We met at Advanced Chassis Dyno and removed the bumper and it was off for all runs. We used a bag of ice to keep the intercooler from getting too heat soaked between runs so that the intake air temp was the same as possible. The outdoor weather was a bit hot and muggy, but stay very close to the same the whole time on the dyno. We also rest the ECU before each set of runs for the new product.

First runs: A Stock MCS
Seconds runs: a Pilo Intake
Third runs: Alta Intake w/ tube
Fourth runs: M7 AGS.

Runs I.A.T. Eng.Temp H.P. Torque
Base 1 129 190 147.3 141.1
Base 2 135 189 150.7 140.6
Base 3 135 189 147.3 142.3
Pilo 1 127 190 159 148
Pilo 2 136 189 148.2 144.1
Pilo 3 136 192 156.5 144.4
Alta 1 127 190 157.9 145.6
Alta 2 132 190 157.5 144.7
Alta 3 133 192 161.1 147.7
AGS 1 113 192 153.4 147.6
AGS 2 118 198 155.1 146.5
AGS 3 129 198 155.1 146.5
AGS 4 127 190 152.6 141.5
AGS 5 133 194 153.5 145.5
AGS 6 133 189 148.7 137.5
AGS 7 127 190 156 144.6

(The final AGS run was with blower fans right over Intercooler and air filter to see if they had any effect)
Over all we could see about 10 Hp from the Pilo over stock, then about another 2 Hp for the Alta. We then saw about a 4 Hp loss with the AGS when just on the dyno, but found that it liked a bit of forced air to almost keep up with the Alta. Once on the street you will get the added forced air, but at a bit more IAT. I have always liked the idea behind the AGS and thought it should make power, so I would like to see what it dynos on a car with your basic mods the most do (15%, cat-back, ECU?). But also this was a hard intake to install. It took a few hands to get things sealed and fitted, but we were also trying to install it in the air on a dyno with only a small area to work with and try not to trip over the hold down straps. With all of this said the AGS sou nded better than the Alta on the dyno. It was a lot deeper sound. But it think for the price and the ease of install the Alta C.A.I. will still be the intake to get. But if a customer wanted to get an AGS I would not try to talk him out of it as I still think there is a place for it.

Thanks,
Chad Detroit Tuned
Sid & Joel

As I said, the above indicates some of the issues with dyno measurements – the testers tried to minimize temperature effects but there is a reasonable I.A.T. (intercooler) temperature difference for different tests – the intercooler obviously cooled down while the AGS was being installed.
The “10 hp for Pilo” claim is interesting, since one of the three readings was massively worse! When you read claimed dyno results, are you reading the best performance or the average?

For me, irrespective of the tests attempt to show the AGS as best performer, it is clear from this data that the Alta gave the best results – but of course we have no value-for-money factor in the figures presented above.
The final AGS run, attempting to cool the intercooler, could have been repeated on any test and would presumably have shown gains above those for the stock, Pilo or Alta intakes.

So next time you read dyno claims, consider how useful they really are – if gains of 20+ are claimed, that is significant, but a gain of 5-10 hp is easily swallowed in real world variations …

“Da MINI” Tshirt

In the style of DaVinci, Joe (JoeRKtect on NAM) has created this design for a limited run of Tshirts that he will be selling to fanatical MINI owners like me:

These shirts cost $25 each (shipping included) and I think they will be very special and unusual – I got my order in already 🙂

Visit this NAM thread to learn more and get in contact with Joe. And hurry, because his order cut-off date is September 5th!

Screw holes!

One of the still-not-right parts of the interior of GBMINI#3 is the screws holding the door panels to the door – they really show up with the red matched paint of the trim, and they shouldn’t.

Recently Gabe reviewed the MyMINI knee pad and I wandered over to MyMINIparts to have a closer look … I did actually order a knee pad but unlike Gabe, now it has arrived I don’t think I will fit it; it does not give a perfect fit to the down tube, and it makes the downtube even thicker so increasing the chance of my leg leaning on it. I should have realized that before, but I didn’t.
Also, it fits to the down tube high up and my knee rests below the bottom of the part!

Anyway, while I was at MyMINIparts I looked around at what else they offer and found some “chrome” caps to cover the door trim screw holes! Ordered, received and fitted:

I would disagree with the “chrome” description; they are more like polished metal and have a somewhat rough look rather than the pure smooth chrome look of the factory “real chrome” elsewhere in the car; but for $8 for the set of four, there’s not much to complain about – and they do look better than the bare holes.