What kind of Limited Slip Diff do we have? And, are Gears an option?

So I am thinking of the benefit I got from taking my Viper and just throwing a little gear at it, and that perhaps the Murci could benefit from the same thing. Those clutch burning activities I feel come directly to the fact that first gear is so damn long. So to fix that, and lighten the load on the engine, what if I threw in a set of gears on the differential (not the tranny).

 

Also while I am at it (also like my viper), I'd like to maybe throw a better LSD in it. Perhaps a Quaffe. Has anyone done either of these tow things? Is there a year in which the Murci had a higher numerically Ring and Pinion setup then my 06 roadster?

 

At this point, my options to going faster (bottom end) are to get lighter (will help top end too, but I dont do much of that), or add more HP (I dont think these cars have much in the way of mods that dont include BOOST), or just throw a Gear at it.

 

I know these cars arent that fast, but I live in the city of chicago, and bottom end grunt is important for cutting through traffic and stop lights.

 

thanks for the help (yeah not your normal lambo owner).

 

Jon

So I am thinking of the benefit I got from taking my Viper and just throwing a little gear at it, and that perhaps the Murci could benefit from the same thing. Those clutch burning activities I feel come directly to the fact that first gear is so damn long. So to fix that, and lighten the load on the engine, what if I threw in a set of gears on the differential (not the tranny).

 

Also while I am at it (also like my viper), I'd like to maybe throw a better LSD in it. Perhaps a Quaffe. Has anyone done either of these tow things? Is there a year in which the Murci had a higher numerically Ring and Pinion setup then my 06 roadster?

 

At this point, my options to going faster (bottom end) are to get lighter (will help top end too, but I dont do much of that), or add more HP (I dont think these cars have much in the way of mods that dont include BOOST), or just throw a Gear at it.

 

I know these cars arent that fast, but I live in the city of chicago, and bottom end grunt is important for cutting through traffic and stop lights.

 

thanks for the help (yeah not your normal lambo owner).

 

Jon

 

haha good luck Jon!

 

i love the approach you always take to modding this thing!

So I am thinking of the benefit I got from taking my Viper and just throwing a little gear at it, and that perhaps the Murci could benefit from the same thing. Those clutch burning activities I feel come directly to the fact that first gear is so damn long. So to fix that, and lighten the load on the engine, what if I threw in a set of gears on the differential (not the tranny).

 

Also while I am at it (also like my viper), I'd like to maybe throw a better LSD in it. Perhaps a Quaffe. Has anyone done either of these tow things? Is there a year in which the Murci had a higher numerically Ring and Pinion setup then my 06 roadster?

 

At this point, my options to going faster (bottom end) are to get lighter (will help top end too, but I dont do much of that), or add more HP (I dont think these cars have much in the way of mods that dont include BOOST), or just throw a Gear at it.

 

I know these cars arent that fast, but I live in the city of chicago, and bottom end grunt is important for cutting through traffic and stop lights.

 

thanks for the help (yeah not your normal lambo owner).

 

Jon

 

Jon,

 

This isn't exactly like a viper, which will actually achieve top speed in 5th rather than 6th gear. So dropping down to a 3.23 or 3.55 gear just makes 6th more reasonably useful IMO, though running 200mph turning 4k rpm has a certain amusing side to it (requires about 750rwhp to pull that gear).

 

The murci will max out 6th, so any gear change will take right off the top end, and raise your cruising rpm. There are a million gear/rpm calculators around that will give you the exact effects of any changes, as it may or may not matter to you.

 

I don't know for certain, but you might have an easier time changing the internal transmission ratios. The viper diff is a glorified dana 44, with the GTS-R being a Dana 60. As such, there is a huge allotment of aftermarket parts available and known dimensions. If you had the gears out of a murci I can give you a contact who custom makes gears, and he could evaluate them to see if it's even possible. Looking at the specs, stock is a 2.53:1, but without knowing the diameter of the ring gear, it's hard to even speculate how much room you have to change things. Since the ring gear dia is fixed, gear ratio changes are made by adjusting the diameter of the pinion gear (gear turned by the driveshaft) and subsequently changing the number of teeth on it, the matching teeth on the ring gear, their angle/pitch, and the thickness of the ring gear so they mesh properly.

 

Last I heard it was in the area of $4k or so to do a custom set of gears, for a known differential. In this case you have two unknown diffs both needing new gears. I tend to think this will be a minimum $20k project by the time you tear everything down, get the gears made, reassemble and install, etc.

 

As well, Quaife will do custom builds, but those definitely don't come cheap.

 

Shit, looking at all of this, you very well may be in the same budget ballpark just letting Alex @ SP put a mild TT kit on it, and that will add value to the car! Doing all this gear mess will be expensive and actually may very well make the car difficult to sell in the future.

 

At any rate, if you want to pursue the gears shoot me a PM and i'll get your some people to talk to.

 

Jon,

 

This isn't exactly like a viper, which will actually achieve top speed in 5th rather than 6th gear. So dropping down to a 3.23 or 3.55 gear just makes 6th more reasonably useful IMO, though running 200mph turning 4k rpm has a certain amusing side to it (requires about 750rwhp to pull that gear).

 

The murci will max out 6th, so any gear change will take right off the top end, and raise your cruising rpm. There are a million gear/rpm calculators around that will give you the exact effects of any changes, as it may or may not matter to you.

 

I don't know for certain, but you might have an easier time changing the internal transmission ratios. The viper diff is a glorified dana 44, with the GTS-R being a Dana 60. As such, there is a huge allotment of aftermarket parts available and known dimensions. If you had the gears out of a murci I can give you a contact who custom makes gears, and he could evaluate them to see if it's even possible. Looking at the specs, stock is a 2.53:1, but without knowing the diameter of the ring gear, it's hard to even speculate how much room you have to change things. Since the ring gear dia is fixed, gear ratio changes are made by adjusting the diameter of the pinion gear (gear turned by the driveshaft) and subsequently changing the number of teeth on it, the matching teeth on the ring gear, their angle/pitch, and the thickness of the ring gear so they mesh properly.

 

Last I heard it was in the area of $4k or so to do a custom set of gears, for a known differential. In this case you have two unknown diffs both needing new gears. I tend to think this will be a minimum $20k project by the time you tear everything down, get the gears made, reassemble and install, etc.

 

As well, Quaife will do custom builds, but those definitely don't come cheap.

 

Shit, looking at all of this, you very well may be in the same budget ballpark just letting Alex @ SP put a mild TT kit on it, and that will add value to the car! Doing all this gear mess will be expensive and actually may very well make the car difficult to sell in the future.

 

At any rate, if you want to pursue the gears shoot me a PM and i'll get your some people to talk to.

 

Yeah, again top speed is irrelivant, my viper was 200+ mph capable (730rwhp) and I never saw north of 160mph. And I only did that ONE TIME (the 160). So that doesnt mean shit to me, and the labor of yanking it all out, and putting it back in, well thats cake. I already extracted the whole front diff and 1/2 shafts, and torque tube. Keep in mind I do NOT have to do the front diff, since I am RWD, it wont matter if I dont match the front, its not in the car . So yeah, thinking about just 1 gearset. And I would never go 3.55 in this car, hell that was worthless in a NA viper, the most I ever did was a 3.33 or a 3.21 which even in this car might be to much when you consider its 2.53 starting point. So at most, I would do like a 2.75 or 2.85, wouldnt even hit 3.07 or the such, as that would be to much gear.

 

I'm going to do a little investigation on this. It might not be feasible, but only research will tell me that.

 

Thanks!

 

Jon

Only 160, and you live in Chicago? I have *heard* late nights there is a great clear loop around 80 and 88 that is super smooth concrete and perfect for high speed runs.

 

And some other thing about people doing standing mile runs, I guess from a specific toll booth to the next bridge is just about exactly one mile.

 

Its all hearsay, from a friends brother, and could be in mexico. . .

 

Dig into it, if I can be of any help don't hesitate to ask.

Only 160, and you live in Chicago? I have *heard* late nights there is a great clear loop around 80 and 88 that is super smooth concrete and perfect for high speed runs.

 

And some other thing about people doing standing mile runs, I guess from a specific toll booth to the next bridge is just about exactly one mile.

 

Its all hearsay, from a friends brother, and could be in mexico. . .

 

Dig into it, if I can be of any help don't hesitate to ask.

 

 

HMMMM... I'd know a guy who did 200 mph through a ipass overhead system. We wouldnt be talking about the same guy? (Not a toll booth, thats pure suicide)... viper guy... boosted Lives around these parts .

 

 

Anyways, the Murci is limited slip in the rear, right? or is it open diff, because they expect it to be AWD with the fronts grabbing too?

 

Curious....

HMMMM... I'd know a guy who did 200 mph through a ipass overhead system. We wouldnt be talking about the same guy? (Not a toll booth, thats pure suicide)... viper guy... boosted Lives around these parts .

 

 

Anyways, the Murci is limited slip in the rear, right? or is it open diff, because they expect it to be AWD with the fronts grabbing too?

 

Curious....

 

That sounds like a PC move, but yeah I know a lot of guys up around there, st. charles/schaumburg/northbrook Few years back I was in town for a couple months and went to some of the regular viper club meets. Is that god awful thing with the wing so big it used cable supports still running around?

 

Streets of woodfield and the chi2k events were always a good time.

 

The murci diff is definitely limited slip, but i'm not sure the exact type (friction cone, plates, or worm gear like a quaife)

That sounds like a PC move, but yeah I know a lot of guys up around there, st. charles/schaumburg/northbrook Few years back I was in town for a couple months and went to some of the regular viper club meets. Is that god awful thing with the wing so big it used cable supports still running around?

 

Streets of woodfield and the chi2k events were always a good time.

 

The murci diff is definitely limited slip, but i'm not sure the exact type (friction cone, plates, or worm gear like a quaife)

 

 

hahaha.. as soon as you said PC, I was like YUP, thats the guy. He offered to build a setup for my Gen 3 Viper back then, I just was always worried about reliability, so I passed on it... but he was a really cool guy, even loaned me his Drag Radials one time. lol.

 

 

Yeah, I am interested in what version of a differential we have, if its gears based, or clutch based, etc. Does it need to be 'pumped up' like the Viper Gen 3 version needed to be, etc.

 

If anyone knows.. please tell.

 

Thanks,

 

Jon

hahaha.. as soon as you said PC, I was like YUP, thats the guy. He offered to build a setup for my Gen 3 Viper back then, I just was always worried about reliability, so I passed on it... but he was a really cool guy, even loaned me his Drag Radials one time. lol.

Thanks,

 

Jon

 

Rock on! P is one of my best friends. We beat the ever living snot out of his old front mount setup for many thousands of miles and it was flawless. This was on a red 97' with a totally stock motor, made right around 800 to the tires on pump gas, just ran out of fuel pump so we never could push it harder.

 

I'm actually building him the tooling for some turbo manifolds which will be released shortly.

 

 

In regard to the diff, maybe call a lambo dealer tech? I don't figure too many people have torn into the rear diff on a murci unless it was a warranty issue.

 

Please update this thread with your findings down the road.

I have wondered the same thing...wether you could put "gears" in a lambo (specifically a 2001 diablo 6.0)...since i too own a viper and its such a common modification on vipers.

LSD, I'm pretty sure it does. It leaves 11's from a roll.

 

Nick

I personally have swapped rear ends before for different gear ratios but I don't think I would go shorter in the Murci unless I just had a hole in my pocket as there definitely wouldn't be a ROI on the mod I don't think. Custom gears would definitely require a couple pieces to be made and wouldn't be cheap.

 

PPG in austrailia might have something made in a straight cut gear set for some of the Race Murcies.

I personally have swapped rear ends before for different gear ratios but I don't think I would go shorter in the Murci unless I just had a hole in my pocket as there definitely wouldn't be a ROI on the mod I don't think. Custom gears would definitely require a couple pieces to be made and wouldn't be cheap.

 

PPG in austrailia might have something made in a straight cut gear set for some of the Race Murcies.

 

 

Sounds like your talkin about tranmission gear sets. I am talking about ring and pinion gear set, I've never heard of those being made of strait cut gears. I'd never do that to my differential, or transmission (noisy)

 

I think you meant 'money burning a hole'

 

no ROI, in what sense, performance increase in 60 foot, or 1/4 mile or zero to sixty? Sorry we'll have to dissagree. And if you meant ROI on getting money back for the mod, please.... no car mod do you ever net your full returned investment.. that isn't even a consideration. I mod for me... not resale.

 

 

LSD, I'm pretty sure it does. It leaves 11's from a roll.

 

Nick

 

 

lol. I am interested in knowing what kind of SLD we have, gears based, or clutch based. Maybe I'll take mine apart to find out

 

11 footers yours leave in first? Must be nice.. but thats never going to happen in an egear car. Traction always wins over gearing in a stock (or slightly modified) 2wd e-gear car. if you get the advantage over the tires, its short lived. You can never do a proper burnout in a e-gear murci.... one of lifes dissapointments. lol. (value being, getting heat into the tires, before a launch).

 

Yeah, I know I'm odd.. actually wanting to do 'car stuff' with my lambo, vs just looking at it, or looking good in it.

I'm going to try to get a Quaife in mine. I've started to reach out to a few people (shops) to see who might do such a setup. I know Tailor Racing does all sorts of Quaife builds. I asked the guys at UGR (no response ), and Heffner (just sent the note tonight).

 

Maybe/hopefully, I'll find someone who makes them for the Murci. And then if I can get a quaife for it... why couldnt I get a set of gears too ;-)

 

We'll see, and I'll share whatever I find out.

 

Jon

haha good luck Jon!

 

i love the approach you always take to modding this thing!

 

 

You my friend now have an opportunity to get back in on the action I've sent you an email. Round 3, here we go

 

In regard to the diff, maybe call a lambo dealer tech? I don't figure too many people have torn into the rear diff on a murci unless it was a warranty issue.

 

Hmmm... why do that... when I can go the much harder route and just figure it out myself. Behold... the power of determination.... (and a huge passion to not let insane lambo repair bills scare me... because I can do it myself)

 

 

 

 

 

 

 

So I have my entire differential over at a very well known gear manufacturing company who do work for some of the 'who's-who' of worlds fastest lamborghini's.

 

I was specifically asked to not share the information out of respect for their customer base, and those shops are not endorsing what I am doing, so I wanted to avoid saying either of their names.

 

With that said, I am not trying to be mysterious, I'll share the company name (but not their customers) in PM, and I'll ask the gear mfg'er if its ok that I post their name as the fabricators of this.

 

But here is what I am working on: I want a better differential (stock one is clutch pack based) and a higher numberical gear ratio.

 

My rationale for a set of gears (ring and pinion), is to reduce the load on the clutch by giving the engine and clutch the advantage over the tires. This will also lead to more rapid acceleration, but a lower top speed.

 

For me, usability is always on the bottom end. I dont spend much time in the 200mph+ range.

 

So I'd rather have quicker off the line speeds, then total top speed. So the MFG'er is going to build me a new set of ring and pinion gears, to work with my stock Murcielago gear box. (Which is extractable without pulling the engine). I am not going to go crazy, but instead of a stock 2.57 ratio, I may go to a 3.0X ratio.

 

the reason I am thinking only the RWD guys will care, is that if you are AWD, then we'd need to also change the front differential to match. I could certainly have them do both, but I am RWD, and saving the cost of modifying my front diff to match, becasue I like RWD. Although I have to admit, shorter gear ratio's on AWD would make the Murci a monster off the line, with far less clutch wear/damage, so I could be pursuaded to do this route, which will double the cost (which I can split with others if they want this too), but if I am owning this adventure my own, I will only do Rear Differential, to save cost.

 

I dont 'need' anyone to join me in this adventure, however, they are going to setup tooling to do this for me, and that cost is a sunk cost, but if they were to build 3-4 of these for other customers, it would lower total cost. Once I am done, and tooling is moved on to the next project, there will be no cost savings for anyone wanted to follow in my foot steps. Its a now or nothing kind of thing. I realize this isnt really the forte of the normal murci owner, so I am likely on my own here (I can live with that), but wanted to offer it up to everyone.

 

My ball park, and its a total swag, is likely $2,000 for the gears. The mfger is in research mode right now, seeing if an off the shelf set will work, but if they have to custom make them, its going to be about 2k. Either way, I'm in.

 

Thanks!

 

Jon

Crikey ! And I thought I got involved !...

 

What's the conclusion, clutch pack LSD ? .... Not like your old Posi Tracs then....?!

 

Edit... Just seen yr post. Clutch it is then.

Well done man, i'm pumped to see you grab this one by the balls!

 

What is the cost delta on making 3-4 sets and reselling them? Many times if one set is $2k, each additional set is $500, etc.

 

Any luck getting a quality diff in there?

Well done man, i'm pumped to see you grab this one by the balls!

 

What is the cost delta on making 3-4 sets and reselling them? Many times if one set is $2k, each additional set is $500, etc.

 

Any luck getting a quality diff in there?

 

Oh my cost if I go this alone is likely $3,500+ ish. The $2,000 was exactly what your saying, a guess to what a nice reduction in actual cost for 3-4 units would be vs a '1 off' cost for me, however, I dont mind paying and being a 1 off setup. So I'm fine either way. Share my hard work (pulling my own diff, car being down, and me doing all the research on a proper setup, etc) and save some money, or dont share, and have something very unique to me.

 

I did this mostly for my self, better, faster, stronger. Without going crazy. Turbos would be nice and all, but I think they bring on additional risk to other components that I just dont want to 'afford.' Obviously its night and day, a turbo car would be insanely faster. But this will make it quicker and a bit more spirited to drive around town.. thats what I am looking for.

Oh my cost if I go this alone is likely $3,500+ ish. The $2,000 was exactly what your saying, a guess to what a nice reduction in actual cost for 3-4 units would be vs a '1 off' cost for me, however, I dont mind paying and being a 1 off setup. So I'm fine either way. Share my hard work (pulling my own diff, car being down, and me doing all the research on a proper setup, etc) and save some money, or dont share, and have something very unique to me.

 

I did this mostly for my self, better, faster, stronger. Without going crazy. Turbos would be nice and all, but I think they bring on additional risk to other components that I just dont want to 'afford.' Obviously its night and day, a turbo car would be insanely faster. But this will make it quicker and a bit more spirited to drive around town.. thats what I am looking for.

 

 

BTW, if someone knows they are coming due on a clutch replacement, that would be the IDEAL time to also throw in a set of gears too. But even if you want to 'shelve' the ring&pinion gears, they wont go bad and you can put them in months, or years later, with the knowledge you saved money and got in on a likely 1 time ever run. But with a clutch eminent for some, the install requires the whole engine-transmission-differential to come out, so the diff just 'pops' off easily once the engine is out. Doing what I did, of yanking it out, while all else is intact, is just becuase my clutch is in great shape, no need to pull anything right now. Hell it was all hand tools to get it out, pretty impressed at the relative 'ease' of getting it out, although admitedly, you'll spend quite a few hours getting parts unbolted. Heck, also seems to be a great time for me to install a set of primary cat by-pass or high flow cats, so I am working that angle too.

This is so awesome. Your car is going to be a BEAST.

 

if I were to change the R&P it would be for longer gears since I do a lot of highway driving and miss Viper MPG.

Ok, I think I just bumped into my first 2 hiccups.

 

1. does the egear or pcm or ECU care about a gear ratio change? will it 'complain' that its not going the speed it expects for the given rpm?

 

2. and this one I already know the answer to Egear cars only, there is built in 'over rev' protection that wont allow the car to down shift if its going to cause an over rev condition. However, with SHORTER gears, that feature will become void, as it wont know that your rpms will be say 500+ rpms higher then it expects when you 'drop it down' a gear and it will allow you to unknowingly. Sure it would then see your banging into redline again and try to switch the gear back to the next highest, but you sure as hell dont want it doing that calculations while your playing at redline. Stick cars have no concern over this, becasue you as a human being can control 'forced over rev' by stepping back on the clutch, and of course learning the car to know when you can down shift. Instead the egear makes you 'soft' and you know that if you ask for it, and it gives it to you (a 2 gear down shift, or even 3), that the computer will let you know whats allowed. Shortening the gears will eliminate render this feature for the most part useless in EXTREME driving.

 

This alone will kill the idea of shortening the gears, UNLESS I find out that my tuner can ADJUST the program wherever it resides, to put in the new calculations based on what I would be doing with a gear change, which mathematically I have decided needs to be either 2.75 or 2.85 to 1 ratio. Top speed would be 185 mph, 60 mph in 6th gear would be 2,517 rpms. 1st gear would max out at 56mph, 2nd 79mph, 3rd 108mph, 4th 139mph and 5th 159. I already told you 6th

 

Oh and did you all know that you can go over 75 MPH in reverse in our cars? WHAT THE fcuk... no wonder why the clutches burn out so quickly in reverse, its so damn LONG of a gear, your killing the clutch creaping along. I was so looking forward to the value 2.85 gears would bring in saving clutch life and noticeably quicker acceleration... I'm really kind of devistated. I think I have 2 issues that may kill the project

 

Might be time to get a new car

OMG, I had no clue about reverse. That is retarded. lol

 

The ECU shouldn't have any change based upon the different gears. e-gear is the same trans as manual with a different clutch engagement. The ECU's in the Murci are so basic, that they should not have an issue, the speed sensors are post diff, so everything should change with the gearing. It would be the same as changing from 1st to 2nd gear.

 

Talk to Jake @ Eurocharged, he is my go-to for tuning and might have some insight on the over-rev issue.

http://www.eurocharged.com/

OMG, I had no clue about reverse. That is retarded. lol

 

The ECU shouldn't have any change based upon the different gears. e-gear is the same trans as manual with a different clutch engagement. The ECU's in the Murci are so basic, that they should not have an issue, the speed sensors are post diff, so everything should change with the gearing. It would be the same as changing from 1st to 2nd gear.

 

Talk to Jake @ Eurocharged, he is my go-to for tuning and might have some insight on the over-rev issue.

http://www.eurocharged.com/

 

 

Yeah, the egear issue is only about the 'drop down' to a lower gear, im not worried about IT complaining about the differential, but i will have no clue and allow you to drop down and over rev the engine in its current state if I make a gear change.

 

Now as far as your 'post differential' speedo. I have to dissagree. I disconnected the rear differential and 'ran the car' in gear and it STILL registered speed. with NO wheels moving.

 

So that tells me, its getting its 'speed' reading from the transmission or the transfer case. Becasue I am in 2wd, NONE of my wheels are moving, and it still registering speed, when you put it in gear and 'row' through the gears. Crazy, right? That tells me its NOT happening at the wheel hubs, its happening at the transmission or transfer case.

 

My car with NO differentials in it, is still registering speed signals.

 

Tricky huh?