Chicago 1/2 Mile Event: Murci vs Diablo 6.0

Thought you guys might enjoy this:

 

 

 

 

 

 

Did the guy in the 6.0 miss a shift or something?

Did the guy in the 6.0 miss a shift or something?

 

 

His best for the day was 142mph and mine was 147 mph. I ran him I think 2 times, both times I won by similar margins. He has an exhaust only, I have exhaust, tune and RWD.

His best for the day was 142mph and mine was 147 mph. I ran him I think 2 times, both times I won by similar margins. He has an exhaust only, I have exhaust, tune and RWD.

 

Oh and there was a Forum member also there with his 02 or 03 Murci coupe, and I think he was also hitting similar numbers as the Diablo for MPH.

 

It was fun going 150mph with the top off the car 'racing'

His best for the day was 142mph and mine was 147 mph. I ran him I think 2 times, both times I won by similar margins. He has an exhaust only, I have exhaust, tune and RWD.

That would explain it, also the SVR wing and what look to be larger wheels will slow him down.. Nice runs!

Oh and there was a Forum member also there with his 02 or 03 Murci coupe, and I think he was also hitting similar numbers as the Diablo for MPH.

 

It was fun going 150mph with the top off the car 'racing'

Yes, performance wise stock for stock I know they are virtually identical. Thats why I was suspicious when I saw a Murci Roadster pulling like that.

I have a friend with a 2006 roadster. Last weekend we finally got out together. I pulled on him in every gear. He has tubi exhaust only.

 

I am rwd and fabspeed.. It's amazing how he just couldn't do anything about keeping up with my car in the straights.

Very cool. Yellow on black 6.0 is cool!

This thread make me wanna go rwd :S

This thread make me wanna go rwd :S

Not all the other threads where there are 4 or 5 of us explaining how much more amazing it is? LOL.. The straight line speed isn't the only benefit.. It's basically everything that is a benefit.

 

I love RWD...

 

uhh Guy´s, i can´t wait for the part´s was Nick shipping to me. Then i convert my Murcie to RWD

uhh Guy´s, i can´t wait for the part´s was Nick shipping to me. Then i convert my Murcie to RWD

 

RWD has big effect on speed. glad mine is already.

Yeah, I was really looking forward to the 1/2 mile event hoping a murci would show up so I could see the difference between the two setups (mostly stock vs RWD). Since the Diablo and Murci were doing the same speeds that day, I am confident that this represents the differences between stock and RWD+Tune.

 

Admitedly, the car needs shorter gears. And since I am RWD, its a lot cheaper to just buy a ring and pinion for the rear then the rear and the front. Not sure if everyone knows this but the lp640 actually has shorter gears then the murcie. So the factory bumped the power by 60hp, and still felt the need to put shorter gears in the car. That tells you something. I think they missed the mark on the murci, they put way to long of gears in it. Going RWD definitely helps, but 'launching' the car with 1st gear being able to do 64 mph is just way to long of a gear. My car didnt slip one bit during any of my runs/gear shifts (on a prepped track), so I know the power is not out pacing the traction, so I'm going to investigate the possibility of a new ring and pinion (Again, before I stepped away when the price was at $2500 to Mfger it). In the murci you can pull the rear diff without taking the engine out, so its really a straightforward 'upgrade' especially for RWD cars. Sure I could go turbos or S/C and make crazy power, but I am not trying to do all that, the murci is my fun car, not my street racer car (GTR is), but I like the idea of 'maximizing' the 'bolt on' capabilities of the car, and then calling it a day.

 

I'm sure with the proper set of gears I can maximize not only my 1/4 time but my 1/2 mile time as well, and keep 'stock reliability' and driveability. Honestly the biggest gain value is going to be the longevity of the clutch, as the shorter ring-and-pinion gears will allow the clutch to not work so hard. After that, I MAY actually entertain the idea of going BACK to AWD by also having a shorter ring and pinion put in the front diff, which then will make this thing a MONSTER coming off the line. The reason the AWD sucks in the murci is the gearing is complete shit, and so the dead weight doesnt do ANYTHING to help you get off the line, and then it hinders you once you get moving. If the gearing was right, you'd get off the line like a bat out of hell (like the GTR) and that would offset the penalty for having to carry the extra weight of the frong differential.

 

If done right, a shorter gear set in an AWD car WILL beat a RWD car setup. (But first I am going to just get better rear diff ratios first, if I can.)

My STOCK GTR with more HP and significantly more TQ (Dynoed on the same dyno) has the following speeds per gear:

 

1st 38.88Mph @ 7000 RPM

2nd 68.54Mph @ 7000 RPM

3rd 98.88Mph @ 7000 RPM

4th 126.37Mph @ 7000 RPM

5th 157.55Mph @ 7000 RPM

6th 198.12Mph @ 7000 RPM

 

The Murci on the other hand:

 

1st 63 mph @ 7500

2nd 90 mph @ 7500

3rd 121mph @ 7500

4th 156mph @ 7500

5th 179mph @ 7500

6th 201mph @ 7500

 

Similar gears in a murcielago would make it an absolute monster off the line. But instead of changing out all the gears in the transmission to match this, the 'cheaper' solution is simply to change the stock ring and pinion in the rear (and the front, if I was going to do this all out). If I do just the rears to this lower level I'd be assured tire burning action, so if I went THIS low, I'd have to go back to AWD to get the grip. But something in the MIDDLE of this setup, will maximize the RWD acceleration.

 

So with even more power the GTR is able to use even shorter gears and accelerate noticeably faster.

 

GTR zero to 60: 2.75 seconds

Murci zero to 60: 3.8 seconds

 

One last note, IF you have 19/20 or 20/20 setup, with the available tires that actually fit/work, you have actually made this even WORSE, as the wheels and tires end up being a full INCH greater rolling radius, which actually raises your speed per gear even more. Like Alan said, those nice big 20's actually HURT performance, because they make an already 'too high geared' car even HIGHER geared.

Nice runs Jon!

Very cool!

Yeah, I was really looking forward to the 1/2 mile event hoping a murci would show up so I could see the difference between the two setups (mostly stock vs RWD).

 

I had an almost stock (exhaust, roadster wheels) 2004 Murci coupe there on Sunday and I have vbox results. It did 146 mph. The shifts are very slow...

I had an almost stock (exhaust, roadster wheels) 2004 Murci coupe there on Sunday and I have vbox results. It did 146 mph. The shifts are very slow...

 

You have a slip saying 146, or your vbox? My buddies vbox run was 1mph faster then his actual slip from wannagofast. Just curious, I wasnt doing vbox, only what they gave me on the slip. Also I am a roadster, so I have the weight penalty (~200 lbs) due to the extra reinforcement (which I think I negated by going RWD) and the arrodynamics penalty of a being completely topless on the runs.

 

So that leaves me with a 'tune' over your setup. Coupes weigh less, and have better Coefficient of Drag numbers. So I'll take it. Thanks for the data.

 

Any thoughts on why the 04 Murci Coupe (stick) that same day was only doing 143mph ?? You picked up 3 more mph then him, and he has full ehxaust also.

Here is the link to the vbox file: https://www.dropbox.com/s/34skvabd09bhrej/vbox-cut.vbo. It shows 145.65 mph at the end of 804.67 meters vs. 146.23 mph on the slip. My other few runs were 142-145 mph IIRC. I never drove a stick Murci but if it's anything like the Diablo, I'm guessing the Egear would be faster.

 

How have you launched? That could account for a couple mph of a difference in addition to the factors you mentioned.

 

I lauched it like an old lady, and thats no excuse for my times, meaning, I am not making excuses. The problem with egear cars with RWD is that you are guranteed SOME kind of slip during acceleration, and if the system notices that, it immediately kills power. So to avoid that I turn of TCS. Ok no big deal right? Next part, in order to get rapid shifts I put 'sport mode' on. Ok no big deal right? Wrong The problem with sport mode on and TCS off, is IF you make the grave mistake of FLOORING the car from a dead stop (like in drag racing situation) the car will IMMEDIATELY REV the rpms to 4500 and dump the clutch with extreme prejudice. And while that might be fun, seeing a huge tire smoking session, you ALSO run the risk of grenading your rear diff, since it isnt able to distribute that force to 4 wheels, it takes it on the chin... not pretty.

 

So to avoid this, I have to come off the line non aggressively, but definitely once I get moving, I slam the gas.

 

This is the only reason I prefer stick over egear on a murci, they are just to fat of cars with such a long gear to allow the computer to control the take off

 

Thanks for the data, it looks like I got you by just 1 mph I was an actual 147 and similar 'change' like you were with the 146, still 1mph is nothing. Excellent data, again, its what I wanted to know and was looking forward to running a murci when I was there.

I tested the sport mode off during one run thinking that perfect shift points might make up for slower shift times but it just resulted in my worst run of the day. I'll try to compare the shift times using vbox data, could be interesting to see the real life difference.

I tested the sport mode off during one run thinking that perfect shift points might make up for slower shift times but it just resulted in my worst run of the day. I'll try to compare the shift times using vbox data, could be interesting to see the real life difference.

 

interesting, because I have noticeably more abrupt shifts in the sport mode, it definitely doesnt take as long to engage the clutch between gears. Would be intersteing to see what the vbox tells you.

interesting, because I have noticeably more abrupt shifts in the sport mode, it definitely doesnt take as long to engage the clutch between gears. Would be intersteing to see what the vbox tells you.

 

I'm seeing about 0.40s for the sport mode vs. 0.51s for the sport off. It's interesting how different the acceleration graph looks for the 458 during shifts, it just accelerates less strongly instead of decelerating a bit like the Murci does.

I'm seeing about 0.40s for the sport mode vs. 0.51s for the sport off. It's interesting how different the acceleration graph looks for the 458 during shifts, it just accelerates less strongly instead of decelerating a bit like the Murci does.

 

Yeah, there is no comparison between a twin clutch and a single clutch. The 458 like the GTR benefits from advanced technology, say in the last 5-8 years. The single clutch system used in the murci, gallardo and aventador is like 14+ years old tech.

 

Yeah, the GTR, I dont even notice it letting off at all as it extremely quick with its gear shifts.

 

Thats interesting about the timing differences, in the shifts, thanks for taking the time to record it and sharing that with me.