what is the biggest disadvantage with the 2003s being with no LSD? should i go ahead and add an aftermarket one or one from the later years?
there is an 03 for sale that i have been interested in...
i don't plan on launching it super hard or anything when i first get it,i just want to be on the safe side...

 

Theres only no front diff. The RS's and MR's i think are the only ones that have the front diff. In all year GSR's there isnt a front diff (i think... Not 100% sure). Theres no real safety issue. If you've ever driven an 03 evo in the rain or snow you'd know what im talking about. I love it when it rains here and the the dumb@$$es slam on their brakes and i just continue pushing the evo faster. If the 03 is in good condition then i say pick it up. Unless you can pick up an 05 or 06...

 

*SIGH* please, if you're going to give technical info, get the right info or word it correctly. 03-04 DO HAVE front diff. it's OPEN diff as opposed to LSD=limited slip diff. the open diff has weaker gears so if you're not careful with launching properly, you can bust it up. also, on corner exit when you get on the gas, the inner front wheel will get most of the power and will spin, so the front will wash out/understeer more compared to LSD version. but ALL evo's have front, center and rear diffs, they're just different types.

 

My open diff is making a little noise but is still hanging in there. Will you need to upgrade to an LSD? Depends on how the previous owner abused it and how hard you beat on it. I believe there are more open diff 03's driving around than modded 03 diffs out there. fwiw. I have dibs on a Quaife to install but that's cause I did donuts, my diff (I think) is making noise, and I want to take my car to the track. Rather replace at my leisure and change the clutch at the same time than break it and then have to replace it.

 

are there any aftermarket ones i can get to toughen it up?

 

quaife

 

Christ! Excuse me for wording stuff wrong! I know the fronts are open diff. I had a 240sx for 4 years. I know something about open diffs... Anyways... You can send your tranny off to shep or TRE and they can rebuild it and put in a quaife if you want. Check the sites for prices.

 

lol don't take it personal, but i've seen too much misinformation spread because of the wrong wording. we're all just trying to help others, so let's do it right

OP: you can also buy a used front factory torsen LSD from RS and '05+ owners who upgraded to aftermarket. that's the cheaper route and it's still a decent torsen diff. if you go aftermarket, you can get either torsen or clutch type. check with KAAZ as well on what they have for the evo. clutch type can be 1, 1.5 or 2 way diff, if you want to track the car and want some specific setup.
FYI, the rear factory diff is clutch type 1.5 way on all evos 03-06.

 

So the acd diff in an 05 gsr and mr is diff from 05 diff in an RS? So the 2003 RS has the same diff as a 2005 - 2006 RS??

 

i think RS started in '04 in USA and in that model year RS didnt have ACD, but it did have front LSD which is the SAME torsen FRONT LSD (not the ACD) as '05+ RS, MR, GSR (unless the front diff had some minor revisions, prolly not). none of the evo's in USDM trim had ACD until 05, but from '05 and on, ALL evo trims have ALL same diffs throughout.
so, you can buy a used front LSD from '04 RS or ANY of the '05+ evos

03-04 GSR - open front and no ACD
04 RS - LSD front and no ACD
05+ RS, GSR, MR - LSD front and ACD
ALL of the above have 1.5 way rear clutch type LSD

i wish mitsu didn't make it so confusing and i wish the bastards included front LSD on 03-04 GSR. i don't care about ACD, but front LSD would be great. oh well, i'll upgrade eventually.

in case anyone wondering about the meaning of numbers for the rear LSD:
1 way means it fully locks up on acceleration ONLY
1.5 way - full lock on accel and partial lock on braking - good street application
2 way - full lock on accel AND braking - this is preferred for racing.
there are also setups where you can adjust amount of lockup and slippage by varying notch angle inside the diff. these are all clutch types btw.
Torsen - the torque sensing LSD that evo's have in front, is a 1 way.
if you have Gran Turismo or other custom car tuning games, install those different types on any of the evos or stis or celica gt4's and see how it affects the handling. also, try fully adjustable diffs and play with their settings.

 

Joizee i apologize for my overreaction it was late and i was just really tired. Anyways i believe your right. The RS was introduced in 04 and has the front diff minus the ACD. The 05 and up have the ACD and front diffs.

 

So that means the front diff of an 05 and up will not fit an 03 - 04 because of acd or can you add the diff without acd? It seems the only diff compatible for 03 - 04 is a rs diff which supposedly is not compatible with abs and the reason they didnt add it to the 03-04 gsr

 

front diff is independent of ACD. it's in a separate casing that you will swap out/into your car, just like if you were to swap with an aftermarket one. it's basically a cylindrical unit that sits between the 2 drive axles, inside the ring gear.
now, as far as the ABS issue, i've spoken to a quiafe rep at a car/parts expo in atlantic city 2 years ago and he said he never heard of the ABS issue and that their diff will work on whatever evo you plug it into, it was also a torsen diff. so if one torsen works in the 03-04 GSR, i don't see why another one wouldn't. the reason there's no ABS on 04 RS is that it's a bare bones track car and many/most ppl remove ABS from track cars anyway. i don't have any good ideas about why there's no LSD on 03-04 GSR, but i would have to guess that since it was the first release of the USDM evo, they made it as cheap and basic as possible (f0ckers!).
now, i did hear something about certain front diffs not being a direct fit, it might've been the ones from '04 RS and they required another spacer or something. try searching on this forum for more answers.
here's some general info on diffs in AWD cars. as you can see, torsen gets the job done, but is not always optimal, yet still pricey:
http://www.musketeerracing.com/diffs.html

tripperfx3: no problemo!

 

So that means if I have an 03 the only lsd i can use is one from an 03-04 rs.

 

the front LSD is just a cylinder part that you "plug in" to your transfer case. it's not directly attached or related to the ACD, so there shouldn't be any problems using front LSD from 05+ evo. <i may be wrong though, you'll have to search>
this is 03 diff vs 04RS diff, the guy says it's a direct swap: https://www.evolutionm.net/forums/sh...ghlight=lsd+rs
replacement LSD is basically a fully enclosed round piece that has either gears or clutch plates inside of it. as you can see, the diff will pop in, and then the driveshafts plug into it from the sides. this is what's inside of it: https://www.evolutionm.net/forums/sh...ghlight=lsd+rs
check with mitsu dealer parts department though, 05+ have the same LSD as 04RS and if they know anything about it.