Lets talk Difs.

[D's GS-T]

So I have a 95 talon which currently has the LSD Rear end, and I've so far decided to go with the Evo III/TRE Max Lock upgraded rear. What is the best way to set up all the difs. for Road Racing a 2G. What are you guys doing, and what do you like so far. ( 1G talk is welcome too)

 

[bastarddsm]

Your probably going to get very few responses to this, as noone even thinks about the rear diff. Be aware that the evo3 rear requires different rear axle parts to work. I'm told that the Evo3 lsd take the same axles as a evo8 lsd, and not the non lsd DSM ones. This is bad becuase they are very expensive.

 

[DSMReviver]

So I have a 95 talon which currently has the LSD Rear end, and I've so far decided to go with the Evo III/TRE Max Lock upgradeded rear. What is the best way to set up all the difs. for Road Racing a 2G. What are you guys doing, and what do you like so far. ( 1G talk is welcome too)

instead of getting the evo3 to work with your rear end, just pull the lsd in the evo3 and put it in 2g diff. It work the same way with all evo's. find reck/ebay evo's rear end and pull out the lsd. send that lsd along with your 2g diff and have tre max lock it. i also wanted the same thing and this is the cheaper route.

you still get the benefit of sold lsd and tre max lock. you just replacing the viscous liquid with the solid lsds. talk to jon long ago at tre and he said he can do it. he can also add his special touch (max lock upgrade) to the normal solid lsd so it will last longer.

 

[D's GS-T]

instead of getting the evo3 to work with your rear end, just pull the lsd in the evo3 and put it in 2g diff. It work the same way with all evo's. find reck/ebay evo's rear end and pull out the lsd. send that lsd along with your 2g diff and have tre max lock it. i also wanted the same thing and this is the cheaper route.

you still get the benefit of sold lsd and tre max lock. you just replacing the viscous liquid with the solid lsds. talk to jon long ago at tre and he said he can do it. he can also add his special touch (max lock upgrade) to the normal solid lsd so it will last longer.

Thats what im doing Im not getting the actually Evo3 Rear, I kind of worded it wrong.

 

[DSMReviver]

Thats what im doing Im not getting the actually Evo3 Rear, I kind of worded it wrong.

its cool, let me know if you find any extra solid lsd's form jdm evo's or usdm evo's

 

[Scott McIntyre]

From: http://www.dsmtuners.com/forums/handling-tech/380330-tre-maxlock-rear-lsd.html#post152363456

I don't have TRE's MaxLock rear LSD, but I do have EVO8 LSD internals in my rear diff and the difference from the OEM VC LSD is night and day. Before the upgrade, I'd get massive inside-rear wheel spin coming out of a tight turn for a good 2 seconds before the VC would lock up. Now it locks up almost immediately and all but eliminated rear wheel spin.

The service was performed by Shep at a cost of $630 including two EVO8 inner cups. At some point I plan to send it to TRE for the MaxLock treatment.

 

[ACM]

I only autocross, I don't road race, so I can't tell you exactly how a Tarmac-equipped 2G will behave on the track. I can however make some observations based on my autocross experience.

I run Quaife front, Cusco Tarmac centre and TRE MaxLock rear diffs. The Quaife and TRE diffs are LSDs, the Cusco is an open diff just like the stock DSM centre diff. You can add the centre VC if required, but unless it's virtually worn out it's pointless - the inner and outer shafts of the Cusco rotate at different rpms all the time, even in a straight line, so the VC will try and pull the shafts back to equal rpms, which will result in a) a 50:50 diff and b) very weird transient handling as it changes from 35:65 AWD to locked 4WD mode. I know this to be true because at one point I tried the car that way and suffered accordingly.

The primary effect of the Tarmac is to make the car loose - the only way it will push is if you get in too hot. The looseness is magnified dramatically by rain, so adjustable damping and rear a/r bar is critical to keep the car pointing forwards regularly.

The primary effect of TRE's Evo-based rear LSD is to stop inside wheel spin; the secondary effect is in helping the car to rotate, and it does so with remarkable efficacy - I noticed this effect more than wheelspin cure, though I didn't have much of that anyway.

The primary effect of the Quaife front LSD in my car was a dramatic reduction in on-throttle understeer in turns. The secondary effect was an almost equal increase in off-throttle understeer ! What this means is that every corner phase must be undertaken under positive throttle - the whole thing, start to end. Any time the steering wheel is not pointed dead ahead the car must be under power, or it simply won't turn.

There's a trend here Each diff promotes oversteer and necessitates an extremely aggressive driving style. This is not a problem at 70 on an airport runway, I don't know that this will be the case on a road course. Obviously some of this can be tamed by camber, toe, damping and springing changes - perhaps even all of it, but I imagine that its inherent character of oversteer would still shine through on occasion, and probably when most inconvenient...

If I took my car out on a road course regularly, the Cusco centre diff would come out and be replaced by a 4-spider with functional VC. I don't like walls, and I'm fairly sure my car doesn't either

 

[123abc]

Essentially though with running the center open you're only 2wd then. It just sends all the power to which ever end has the least grip.

 

[ACM]

Essentially though with running the center open you're only 2wd then. It just sends all the power to which ever end has the least grip.

It doesn't turn out that way actually. Even on a ProSolo launch - similar to drag launch - the car breaks all 4 wheels loose, although I never got a launch quite as good as I did with the 4-spider+VC. Practice, probably.

Running in this mode will overpower the stock VC rear LSD however, you do need the Evo rear.

 

[aaronmatusz]

I'm thinking a 4-spider center with VC and a torsen up front would be a good start for road coarse.
What say those with drive-line experience?
Is there such a thing as a one-way clutch-type front diff for DSMs? That might be neat as well...

 

[Dallas J]

Here are the combinations Ive tried on my 95 which happens to have ~425-450ft-lbs of torque in auto-x configuration with 275 v710s.

Stock - Its a pain to put any power down. Pulling out of the corners was basically all wheel spin. Understeering under heavy throttle unless thrown sideways but even then would understeer at corner exit.

Quaife Front w/ 4spider center and worn viscous center - On throttle understeer was reduced but by far not eliminated. Mid corner seemed to be helped the best by this, but still pulling out of corners would now spin the inside rear enough, what I think, start locking up the center and send to much power forward. This also caused corner exit understeer and meant I had to modulate throttle at exit.

Jon's last EvoIII diff (His personal diff actually) with Max Lock conversion - Holy crap, what a difference. Now the car will throttle rotate nearly as well as my Evo with the same diff. Don't think this means if you're understeering you can jab the gas and magically oversteer. The front needs to have grip otherwise the rear will just push the car further into understeer, but when driven properly and you roll into the throttle on exit the rear will stick out just a bit with amazing controllability.

If I were to do it again, the rear diff would have been the first mod and quaife the last.

 

[cioc]

My driveline modifications went exactly the same as Dallas J. The Quaife w/ 4 gear spider went on first. I did notice a nice difference getting on throttle sooner but ultimately the car still did not rotate. I just put in an EVO 8 rear diff done by John Shephard and this was by FAR the best handling mod I have ever done. Mind you I have JIC coilovers from John Mueller, full polyeurethane bushings, moustache brace/rear subframe delrin mounts, 1" rear swaybar, full cage, active toe eliminator, etc. Getting this thing to turn is not new to me but I've FINALLY found the recipe. Next stop is some tubular arms with roll center adjustments so I can get this puppy lower.

The only negative with the clutchpack diff is that it is noisy as hell. Parking lot u-turns sound quite destructive.

 

[Dallas J]

My driveline modifications went exactly the same as Dallas J. The Quaife w/ 4 gear spider went on first. I did notice a nice difference getting on throttle sooner but ultimately the car still did not rotate. I just put in an EVO 8 rear diff done by John Shephard and this was by FAR the best handling mod I have ever done. Mind you I have JIC coilovers from John Mueller, full polyeurethane bushings, moustache brace/rear subframe delrin mounts, 1" rear swaybar, full cage, active toe eliminator, etc. Getting this thing to turn is not new to me but I've FINALLY found the recipe. Next stop is some tubular arms with roll center adjustments so I can get this puppy lower.

The only negative with the clutchpack diff is that it is noisy as hell. Parking lot u-turns sound quite destructive.

What fluid are you using? Mine was reeeeaaaaallly noisy with Redline (forget which one I was using of the top of my head) but switched to diaqueen LSD oil and it was 90% quieter.

 

[cioc]

I went straight with DiaQueen and was told that if that didn't cure it to use a friction modifier. If it's not harmful I'll live with the noise but the first time I heard it I was sure something was very wrong. What an amazing difference right? The first time I test drove the car I took it down a country road where I live and really laid into the gas as soon as I turned the wheel. I was SHOCKED as I completely hung the tail out. It will still take some getting used to. I went off course at Pocono last month doing the same thing. I've been driving this car for 18 years and it's a whole new animal.

 

[kchaazz]

My driveline modifications went exactly the same as Dallas J. The Quaife w/ 4 gear spider went on first. I did notice a nice difference getting on throttle sooner but ultimately the car still did not rotate. I just put in an EVO 8 rear diff done by John Shephard and this was by FAR the best handling mod I have ever done. Mind you I have JIC coilovers from John Mueller, full polyeurethane bushings, moustache brace/rear subframe delrin mounts, 1" rear swaybar, full cage, active toe eliminator, etc. Getting this thing to turn is not new to me but I've FINALLY found the recipe. Next stop is some tubular arms with roll center adjustments so I can get this puppy lower.

The only negative with the clutchpack diff is that it is noisy as hell. Parking lot u-turns sound quite destructive.

Hey, Dallas J, Ive got full urethane bushings, including the rear subframe bushings, Jay Racing rear toe eliminator, RM front and rear bars and Im just using the BC BR coilovers for now, since they received a good review when tested on a road coarse EVO, though the car was a couple seconds slower than it was with their KW's. Anyway, Im almost finished with the car, and Im wanting to do the Evo dif as well, but Im curious as to which inner cups you ended up using on your axles. ACM has stated before that the 2G short inner cups dont fully engage the splines and the ring doesnt quite click in, but do two 1G short inners work with the EVO dif??

 

[cioc]

Talk to Tad at the driveshaft shop. My cups are EVO 8 cups. The dust shields will not fit but the axle seals do the job just fine. Here is the difference between the EVO 8 cups and the stock 1G cups.

 

[Scott McIntyre]

I also am using EVO8 cups for my rear diff with EVO8 internals (which Shep built).

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Currently in the car, I have a TRE RipGrip front, Cusco 35/65 center (with no VC), and EVO8 rear. The car has a lot of power-on oversteer now, almost too much. As Charles has alluded to, on the road course a better setup may be a 4-spider instead of the Cusco. I briefly ran my car that way last year and the car was much more controllable.

Here's a video clip showing a couple instances of power-on oversteer with my RipGrip/Cusco/EVO8 setup. Some other things happen too, but that's for another thread.

<iframe width="640" height="360" src="http://www.youtube.com/embed/xYFfIgVN95c?rel=0&amp;hd=1" frameborder="0" allowfullscreen></iframe>​

 

[kchaazz]

Cool. Its looking to me that I can machine the stock cups to fit the EVO Dif Ill see if I can get my hands on one from one of the EVO guys here in town and try it out!!

 

[DSMReviver]

Other then clutch type rear end there are also gear type lsd. The most well know is Quaife helical Lsd's. They are quiter, engage smoother, and no clutch plates to replace. They relie on helical gears to distribute the torque where its needed. They will last longer and will never have to replace the helical gears. Quaife only make helical rear lsd's for Evo 4-9. But you can still purhase them and install it in our diffs just the way you would with evo 3 lsd.

QDH18B - Quaife Engineering

This would be good investment because you don't have to deal with replacing lsd clutches later. Its a gear driven LSD so its gonna be more reliable.

This is just one of the options we have for our cars...

This is how Quaife Helical Lsd's work. http://www.roadraceengineering.com/quaife.htm

 

[kchaazz]

&#163;585.00= $920.03. Is that cheaper than the TRE Maxlock upgrade, anyone?? Might be, after shipping the rear end back and forth and all. A friend of mine has already bought Quaife front and center diffs, though he hasnt put them into the transmission yet. Ill have to tell him about this. Thing is that those EVO inner cups are probably several hundred dollars too. Anyone have pics of the EVO cups next to the 1G non LSD cups???

 

[Scott McIntyre]

Oh, I should add that I use Redline 80W140 GL-5 gear oil in my rear diff (EVO8 internals) and I never found it to be noisy. When I installed poly rear diff bushings it got pretty noisy, but prior to that it sounded no different than stock. YMMV

 

[kchaazz]

^^ Hey, Scott, do you have a price for those cups, or were they just included in the entire price of the Dif when you got it??

 

[ACM]

You wouldn't want a helical diff in the rear of an AWD (2G) DSM - hard cornering unloads the inside rear and it will often come up off the ground, at which point a helical LSD becomes an open diff. Also, you can tune the car's handling with a clutch diff by varying the preload, the number of plate faces in contact and the ramp angles - you can't do any of that with a helical diff, it simply is what it is, for better or worse.

A helical rear might be OK on a road course with lowish grip, but then so would the stock VC LSD wouldn't it ? If you are running real race tyres and pushing a 2G hard, you _will_ unweight the inside rear if the car's well set up. Assuming you don't have gobs of aero keeping you down, of course

I don't know about 1Gs, but the 2G non-LSD rear axles are the correct size for the Kaaz/Cusco/Evo I/II/III rear diffs, the short VC LSD axle is too short, with only half the spline length engaging into the side gear; the splines will get ripped off after 3.5 ProSolo events, and the car will be coming home on a trailer from the 4th event.

 

[kchaazz]

You wouldn't want a helical diff in the rear of an AWD (2G) DSM - hard cornering unloads the inside rear and it will often come up off the ground, at which point a helical LSD becomes an open diff. Also, you can tune the car's handling with a clutch diff by varying the preload, the number of plate faces in contact and the ramp angles - you can't do any of that with a helical diff, it simply is what it is, for better or worse.

A helical rear might be OK on a road course with lowish grip, but then so would the stock VC LSD wouldn't it ? If you are running real race tyres and pushing a 2G hard, you _will_ unweight the inside rear if the car's well set up. Assuming you don't have gobs of aero keeping you down, of course

I don't know about 1Gs, but the 2G non-LSD rear axles are the correct size for the Kaaz/Cusco/Evo I/II/III rear diffs, the short VC LSD axle is too short, with only half the spline length engaging into the side gear; the splines will get ripped off after 3.5 ProSolo events, and the car will be coming home on a trailer from the 4th event.

Ill take your word for it regarding the Quaife rear, sir

So, being unfamiliar with 2G axles myself, do the 2G non LSD inner cups fit on a 1G rear axle?? I suppose perhaps I could get with DSMGRAVEYARD on this subject, or see if I can machine the short vc LSD axle to fit correctly.

 

[MidShipCivic]

Tons of C6 road racers use quaife rear in their transaxles you cannot compare the tuning of a clutch type vs the helical because clutch type tuning effects it's locking force. Helical do not work this way they aren't locking differential.

Curious to the one saying that have you broken the Quaife rear LSD in your car?