mksevo

Hey are there any of you guys doing some testing and tuning on a 2 wheel dyno. I have heard some suggest jacking the rearup and other state you have to remove the axle and attach some kind of plate to the transfer case. I dont have a local 4 wheel dyno but i have a guy with a 2 wheel dyno who thinks he can get this to work.
is there any electronics in the rear or transmission that would keep it from working properly. i know there some HP lost to the spinning wheels but it still would be a starting point.

en1gma19

iTrader: (23)

Buschur racing uses a 2 wheel dyno. a 2 wheel dyno will give you a higher number because less hp is lost thru 2 wheels than 4. I don't know if I'd feel comfortable going WOT with the back of the car just jacked up though. Sounds scary to me.

aboh6leenz

iTrader: (30)

interesting because i'd like to know also.

mksevo

i think you have it backwards , it will give you a lower number due to the fact you are still spinning the rear wheel and driveshaft and your not able to use any of the rear wheel HP . the EVO is 50/50 split , so even if you spin just the front it will still put power to the rear wheels and hence take power from the front. i do know about buschur but he is only using it on a 2 wheel drive EVO they have modified for testing. and it will read higher just because it has less drivetrain loss. my thoughts are if the transfer case is fixed at 50/50 then where does the other HP go when the wheels are up in the air.

OZrallyracer

iTrader: (5)

I take back my previous statement, on the 03 evo it does have 50/50 split torque distribution, unless you have an 05 w/ acd that will alter this setup.

mksevo

OZ i will add to my statement, you may be correct with the ACD setup. i am not well versed on that setup for torque spliting. would be different on each setting. but thanks for the update.

OZrallyracer

iTrader: (5)

Yea for some reason I thought that the evo's were previously a 60front/40rear or 70front/30rear. I'm not quite sure why... but you are correct in stating that you will not get accurate results from a 2wheel dyno, due to the fact that yes the rear wheels are getting powered, though if you do it, you would get the best results from the front wheels seeing as there is less rotating mass getting the front wheels powered than compared to the rear wheels. Like said above, there is some form of converting the evo to rwd or something like that where you disconnect the front wheel axles and put something in the transfer case so that it sends 100% of the power to the rear or something like that. I remember a couple months back mitsu was offering some deal for evo owners who submitted their cars to some smog/performance tests of some form or another, and converting it to 2wd was one of the requirements.

mksevo

anyone else have any info , I cannt believe i am the onlyone trying to get this worked out .

anyone
anyone

mksevo

well, got the car on and here are some runs, my first was my current setup , cat back with downpipe, cams, IC , FMIC, 22 boost 93 octane gas, had some kind of spike thing happening at 6000 then it pauses. not sure whats going on. if this is due to knock, some electronic torque split or what. 2 nd run is with header, turbo outlet , and hiflow CAT. 35 hp and 30 more torque not bad really , 3rd is the comparison, can you say area under the curve. nice gains all the way across and you can tell the boost seems to come in earlier. now i dont understand how it went richer unless i had some retard put in by the ECU. i am still waiting on some ECU electronics to fine tune. it was street tuned with dyno flash at an A/F of 11.2-11.4 . I can only calculate that since the rear wheels dont get calculate i should be a good bit of real HP above the numbers i got. this was more for checking benefits of mods than to try and tell me my real HP. anyone else done any 2 wheel dyno time.

OZrallyracer

iTrader: (5)

Nice #'s, i've done a little reasearch on the torque split of evo's and apparently due to the setup of the transverse I-4 engine in the evo, it is not possible to send more power to the rear wheels than 50/50 dist. due to the fact that the transfer case directly powers the front wheels and the acd system is after the t-case, it cannot take more than 50% of the power from the front wheels, I know for a fact that the AMS evo is being tuned on a 2wd dyno on the front wheels, you may want to contact them.

OZrallyracer

iTrader: (5)

In this thread right here there's a video of them tuning on a 2wd dyno, so give ams a call if you really can't access a 4wd dyno.
https://www.evolutionm.net/forums/sh...hlight=ams+evo

mksevo

Thanks , just sent him some mail. i know this car is making more than 300hp, hopefully i will get some 1/4 mile time in the next few weeks with trap speeds.