[Dean]

5M vs 6M

I think Aaron (SilverMk2) and SupraBob have the right idea on the 6M...

See http://www.geocities.com/MotorCity/Pit/9975/dataBySubject/GasolineEngines.html
and
http://www.geocities.com/MotorCity/Pit/9975/enginepix/powercurves/6M-GEU.gif
for a very nice comparison of the two motors.

The 6M was rated at 190 HP, 192 lb ft of torque, in the Japan domestic market. No cat, no emissions equipment.
The 5M (83-86) was rated at 175 HP, 177 lb ft of torque in Japan domestic
market. No cat, no emissions equipment.
So, the 6M only had a gain of 15 HP and 15 lb ft of torque vs the 5M.
I believe that the Japan spec ECU's had more aggressive timing and fuel maps as Bob says. I've been told it is due to the fact that they had higher octane gas in Japan, and their owners manuals specified running hi-octane only.
Locally, Rob's German spec (same ECU and tuning as Jap spec) Mk2 ran a 15.9 all stock. Stock intake, puny stock exhaust, etc, even 3.73 rear gears!! I've never seen any other totally stock Mk2 run less than 16 sec in the quarter.
Mark's 6M 82 runs 0.8 sec faster in the quarter than my 83 with 5M. Our cars have similar mods, cool air intake, 2.25 exhaust, advanced timing. He has a header, I don't. According to a HP vs time vs speed spreadsheet that I have, that means he has 25 HP more than me.... 15 HP from the 6M, and 10 HP from the header. It seems to make sense to me.

 

[Dean]

Suprafiend; Yes, the German spec car is supposed to be lighter than Canadian/US spec cars, by about 180 lbs according to the literature. Rob and I are going to weigh our cars at the same scale on the same day, with full gas tanks, just to see how much difference there is for sure.

Rock; You will definitely notice a difference with a 6M vs a 5M. 8 tenths of a second is a big difference. And Mark's car is capable of better times than a 15.3, it could probably do mid to high 14's with a dry track. That's a lot faster than 16.1! I've heard that every tenth of a second in the quarter mile is approx a car length ahead at the finish line. For example 1.3 seconds is 13 car lengths.... Huge difference, spectators wouldn't even consider it a race!

Cheappower82; Going from 15.6 to 14.9 indicates a gain of 25 HP.
Going from 88.5 MPH to 90.5 MPH indicates a gain of 15 HP.
Either way, pretty significant gains, and about what I'd expect from a 6M vs 5M.

 

[Dean]

Well Mark, I guess I could have beaten my 16.1, if I'd had better tires. Might have gotten into the high 15's if I'd had better grip. Now that I have some 15x7 rims on the car with slightly better rubber, I'd like to run it again. Maybe even run one final time with my modded PS headers when I get them done, just for comparison. Then go turbo and run it again.
Wanna go to Cayuga some Friday night or Sunday afternoon for Run-What-U-Brung Fast'n'Furious Racing?? (Yes, the F'n'F is part of their tagline this summer...) :roll: