SloEvo12

iTrader: (8)

Alright... I'm not trying to get flamed, start fights, get a thread closed, or anything like that. I am genuinely trying to understand and hopefully find a resolution to how to get the car to function correctly in a 2wd configuration (fwd/rwd). I've searched and read enough things related to this to know that everyone is going to say "Why?!" "That's stupid" or whatever else. I'm not trying to drift the car, do burnouts, etc...

Here's the reason - I have a friend who owns a shop with a 2wd dyno. It's a DynoDynamics Dyno (my favorite tuning tool there is) and that's what I'm trying to do tuning on. I'm attempting to do several different tests to the car (mostly turbos) and I don't want to pay for an entire day of dyno time when I have a friend that will allow me to strap the car to the dyno for a week if I need to do so. Additionally, if DynoDynamics dynos are awesome for load based tuning and will likely give me the best opportunity to really dial in each break point on the AEM.

So... hopefully this doesn't start a war. If anyone has any ideas on how to make the car 2wd please help me out. I'm not really certain what the issues are that are different than something like a VCE for a DSM. I'd rather not do something that will destroy/ruin a t-case, but I'll do something reversible and spend a few bucks if need be. Any assistance is greatly appreciated!

Thanks!
Trevor

llDemonll

iTrader: (21)

if you're going to run it as AWD, tune it as AWD

SloEvo12

iTrader: (8)

Thanks for the input, but load based tuning doesn't care if it's awd, fwd, rwd... I can apply as much or little load as needed (search Dyno Dynamics to understand how many options I really have when I say that). Only mechanical parts will need to sit out on this - I.e. the rear axles, output shaft on t-case, front axles? Whatever it is that I need to do to give me 2wd.

wjamyers

not sure what the actual safety margin of driveline components is expressed in percentages but I'm pretty sure you will be doubling the load on whatever components you use to measure 100% of the cars power in 2WD mode, assuming that it's even possible.

MSEngineering

Regardless a vehicle will need road tuning.

roach85

Why not just road tune the car? Seems a lot more reasonable than modifying the drivetrain to make it 2wd. Which in turn will more than likely lead to other problems. "Everything was going great then my trans let go" something along those lines

SloEvo12

iTrader: (8)

I was hoping that this wouldn't go this direction... which is why I prefaced it as I did in the first post.

Road tuning a 700whp car several times (i.e. multiple turbo setups) is not something I want to do. It's not a safe proposition. I can simulate nearly every load combination that exists with a Dyno Dynamics dyno, so I'm not sure that road tuning even has a place whenever that dyno is involved.

My buddy's shop has had no issues dynoing GTRs and other AWD vehicles. My GC SRT8 is easy convertible to RWD. I don't get why everyone gets so sideways about making an AWD car into 2WD - it's really pretty common and usually not a big deal (unhook a couple of things). It shouldn't be a crisis to remove the front axles, rear axles, or even something like pull the pinion out of the t-case for FWD mode. I'm just not certain what potential issues exist in any of those strategies - I know with DSMs you needed a VCE and you could be 2wd. For some reason no one has any answers for Evos...

SloEvo12

iTrader: (8)

No one has any constructive ideas/information about making an evo temporarily 2wd?

phizzalot

iTrader: (3)

Ive seen people remove front axles but leave the cups still in the transmission. Also some work was done on the inside of the transmission to the vc I believe to get it to work.

This should give you some ideas.

94AWDcoupe

iTrader: (125)

there is no simple solution. you can make it fwd by welding the viscous inside the tcase. drop the driveshaft. this of course ruins the tcase and can only be used for dyno in 2wd.

SloEvo12

iTrader: (8)

Thanks for the link. I appreciate the constructive assistance!

Only thing - I think that a DSM and Evo have quite a different transmission/t-case setup? Doesn't a DSM have the front diff in the trans whereas an Evo has it in the t-case? I'm aware of the VCE for DSMs, but I haven't seen anything like that for an Evo (not sure an Evo has one to be honest?).

Anyone else have any more information? Is there a viscous coupler in an Evo trans? Can a DSM VCE be used for an Evo? Again, my understanding is that an Evo doesn't have one in the trans because the front diff is in the t-case, but I'm really not well versed in this... which is why I created the thread!

SloEvo12

iTrader: (8)

Why would it ruin the t-case? If I could source parts from a blown up t-case and weld those, put them in my second t-case, use it, return it to stock and be done?

Any chance you have more information on this? Does anyone offer a VCE for an Evo?

fast3voviii

iTrader: (3)

Evo people are very think and have no imagination.

If you really really do some digging, Rhys Millen converted a Evo 9 to RWD for Tokyo Drift. He even sold the kit.

I think your best bet just for dynoing would be to remove the rear axles as if I remeber correctly they bolt on where in the front they are splined on.

Manimal

Why not just remove the driveshaft.

SloEvo12

iTrader: (8)

Thanks for the feedback. I have some concerns about removing the driveshaft as I'm not sure if the t-case will need the "load" the driveshaft would put on the diff, ring, and pinion? I was thinking about pulling the pinion out of the t-case though as I feel like that would effectively make fwd?

I was thinking that removing a set of axles in the back may be a good idea as well. That makes a lot of sense to me as the clutch pack in the rearend shouldn't be adversely affected (because it causes it's own load unloaded?) by removing the load and it should still keep load on the t-case (where I think you need some?)? If they unbolt and don't cause drama that's a plus.

Ultimately, I was really hoping someone could add to this about what parts of the drivetrain MUST be loaded, which parts can be unloaded, etc...

Thanks again - I'm feeling more optimistic that maybe this will take a turn and be helpful soon!