Yes Jan was here in Dec, we are planning another in the spring (post Dragon) for our fair weather owner's

 

 

In december my mini was parked in someone else's driveway with no clue about the wonder future awaiting it here in detroit

 

Come and have some Fish and Chips next friday

 

You're a knucklehead sometimes Gnatster - Jan knows better than that, I wouldn't ever do that to him.

Have a bad day or something?

 

Either that, OR he's being sarcastic

 

Jan,

DKStone was nice enough to stop over and give MSF and myself a ride in his RMW tuned and modded car and all I have to say is jesus that thing pulls hard as hell.

 

glad to see Trevor is having fun with the Duke!
hope to see everyone in a few weeks

 

Knowing gnatster personally, he's usually being sarcastic

 

 

You could do a simple test of acceleration, from 50 to 90 kph or 90 to 130
(that's around 30 to 55 in 2nd gear and 55 to 80 mph in 3rd), from car at steady speed, pressing the gas pedal and start the watch toghether and stopping it when you reach the speed.

OR you can do a video with your mobile.

It's a lot more effective way of measuring the real improvement of a modification. Just to have a few times for comparison:

- time - speeds from to - owner nickname - specifications (sorry for the italian language)

- 2"56 50-90 Vcc-Antonio - Cooper S JCW GP 2006 (5500 Km,cerchi 18",meta' serbatoio, peso pilota 95 kg peso passeggero 90 kg,fondo asciutto,DSC on)

- 2"75 50-90 Generale Cooper S ?? (mezzo serbatoio di benzina, amico, ???)

- 2"88 50-90 paranoid77 Cooper S 2006 (25800km collettori obx,terminale powerful,puleggia alta -15% v2,0,filtro pannello bmc, camme schrick,cerchi 17"(star bullett), mezzo serbatoio di benza, 78chili di guidatore)

- 2"90 50-90 ABJCooperS Cooper S (R53 06/2005, scarico JCW non silenziato, Colli OBX, Kat originale, Filtro JCMotorsport con Sprintfilter , Albero a camme schrick, Inniettori maggiorati JCW, cerchi da 17"+Bridgestone R040, peso: io 70 + lei 48)

- 3"06 50-90 FBRIATORE COOPER S JCW 210cv (44000 km, cerchi da 18" JCW che non sò come si chiamano quelli a 5 razze comunque, 1/2 serbatoio, pilota 72kg + più qualche pacco nel bagagliaio circa 6-7kg)
4''90 91-131 (3/4 serbatoio, bagagli vari ad esagerare equivalenti a 20kg)...

- 3"15 s 50-90
4"85 s 90-130 TommyGunn cooper S R56(stock, 2150 km, guidatore 75 kg, pieno di benzina, 5°c)

- 3"20 50-90
5"03 90-130 RossocooperS Cooper S R56 (cerchi 17, gomme non RFT, guidatore 94 kg+passeggero 72, tre tacche su dieci di benzina, filtro Alta Performance)

- 3"43 50-90 Axiss Cooper S (una tacca di benzina, powerful, pannello, 17" e assetto completo).

 

yes,yes all good ... now back to work testing the 2.0l stroker!!! damb it .!!!

 

I'd question the tuning job unless it was shown with the A/F throughout the dyno testing. When I've had my bike dyno tuned it would show the A/F ratio for the complete dyno run.

 

Which tuning job are you questioning?

 

The tuning job that is on the first page or any other tuning job that had large improvements in power. Without a complete A/F chart - you do not know how healthy the engine is tuned.

 

See charts on post #54, they show a healthy engine.

 

I wouldn't call A/F ratios like that healthy. From one extreme to another. 15.5 down to 12.5

. Any mixture less than 14.7 to 1 is considered to be a rich mixture, any more than 14.7 to 1 is a lean mixture -


" the stoichiometric air-fuel ratio (14.7:1) that is the ideal ratio for lowest emissions, but this isn't the best ratio for power. It used to be that 12.5:1 was considered the best power ratio, but with improved combustion chambers and hotter ignition systems, the ideal now is around 12.8:1 to 13.2:1. This is roughly 13 parts of air to one part fuel. It's what combustion engineers call an excess fuel ratio and is intended to ensure that all the air is used to support the combustion process. This is because air is the oxidizer in combustion. Too many enthusiasts think that adding additional fuel beyond the ideal to create a richer mixture will make more power. This doesn't work because you can only burn the fuel when you have enough air to support combustion. That's why engines make more power when you add a supercharger or nitrous--you're shoving more air in the cylinder so that you can burn more fuel. Regardless of the amount of air in the cylinder, it still requires a given ratio of fuel to burn. Add too much extra fuel, and power will decrease."


"
When it comes to fuel mileage and increased fuel efficiency, this ratio changes again. All new cars run at 14.7:1 air-fuel ratio at part throttle because this is the lowest emission point. But depending upon the engine, it's possible to run an engine at leaner mixtures like 16:1 or more at part throttle to gain mileage. The difficulty with this is that driveability and throttle response suffers at these ratios. Engine response is lazy and stumbles are commonplace. Each engine will be different, but there is fuel mileage to be gained by fine-tuning your carburetor. Don't be intimidated by these lean mixtures at part throttle. You won't burn the engine up since it is making very little horsepower at part throttle cruise--often less than 30 hp."


On the mini. You must factor in detonation, pining, spark plugs, etc etc.

This is what a good A/F ratio should be like. 15-1 then down to 13-1.

 

Just curious what your experience is with tunning these cars? Not saying anything against you, but you seem to be new, only 30 post's here. But I know Jan from RMW, who this post is mainly about, has probably done 150-200 dyno tunes in the last few months, who should we belive?

 

Engines are mostly the same. Be it a high performace Harley drag bike or a moddified ATV, BMW motorcycle, or a supercharged V8 all of which I've owned. A/F ratios need to be within certian ranges to function properly. For long term engine reliablity and street driving. Making a dyno queen engine tuning can be done with ease.

Look at the second dyno chart A/F ratio and compare it to the 50hp increase tuning job.

post that a/f ratio chart on any engine tuning chat board and you'll see the replies.

 

Obviously there is a lot more involved than the stoichiometric air-fuel ratio...especially in a supercharged car.

 

just to clarify the Pberry dyno... on that dyno the a/f is 1 pt richer than what it shows. Yes we tune cars to 11.5 area because this is where we have found the cars to make the most reliable power and longevity of the engine.

If you want to tune your car to 13:1 go ahead... I will gladly sell you rebuild parts

 

So if you tune a car to 11.5 then why is there such a huge range in your A/F ratio chart. 15.5 down to 11.5.

You say 13:1 is to lean and will damage the engine. But every OEM car that was tuned in a million dollar labs is around 14:1. Every motorcyle I've tuned was around 13:1 Almost every stock engine I've seen dyno tested has at least 13:1 during WOT. Which is why on the above dyno chart the A/F ratio chart has a red line for 13:1

you say 13:1 is too lean - yet the majority of that tuning job is above 13:1. Your only less than 13:1 for about 500rpms 6000rpms-6500rpms.

 

reply: these are the same answers imho. the dyno shows one point leaner meaning that the car is actually 1 pt richer than shown.

please don't post a "zinger" if it isn't logically and fundamentally hilarious.

while you are new to the forum i appreciate your input and would appreciate a debate on the values but i would not like to see mud slinging. if charger can show us his numbers i'd like to see them but i will continue to subscribe to the idea that the "butt-Dyno" is the real case and point.

as stated by Jan the M45 Eaton needs more to remain cool at normal engine temp

 

I'd agree the m45 mini could take advantage of a richer mixture to cool down the chamber. This also effect spark plugs and emmisions. But look at the chart - it stays well above 13:1 for most of the dyno pull.


I will follow the decades of engine builder and car manufactors over a backyard mechanic (not saying anything bad about Jan. I'd buy his heads and CP pistons if I wanted more power - nothing personal. Just engine talk.)

http://www.jagweb.com/aj6eng/superchargers.html


http://www.autospeed.com/cms/A_1595/article.html

 

From the same article that you quoted:
"A well-tuned engine used in normal road conditions has an air/fuel ratio that is constantly varying. At light loads, lean air/fuel ratios are used, while when the engine is required to develop substantial power, richer (ie lower number) air/fuel ratios are used."