Second gear launches are GOLDEN!

[Orlin]

Originally Posted by Jeef Beef

That's at the wheels as well...assuming 15% drivetrain loss (quite a conservative estimate) that's about 770nm at the crank.

Safe to say that car makes more than 700nm

[Jeef Beef]

Originally Posted by Orlin

Yours wouldn't be too far off that figure

[Orlin]

Originally Posted by Jeef Beef

Yours wouldn't be too far off that figure

That makes me a happy man long live the N54!!!

[adrian@vishnu]

I think a well setup N54 engine has the power to do mid 3 0-100. But I don't think it would be possible without drag tyres cutting a sub 1.8 60 foot. I know a bit about the OBD2 system and the speed coming from the DME (the guage uses the same data feed the Procede uses as they work togeather on cars with Procede). It should be the left rear wheel speed. It would be effected by tyre size and wheel spin. If the rear left is spinning, it will read high on speed. I once tested my car with a G-tech setup. Best I could do was 4.6. That was with Continental 255s, and the car had enough power for better, but wheelspin was the issue.

If you can get your hands on an accelerometer based system to compare, that would be interesting... V-box/G-Tech. It would be mighty impressive if you were hooking up for a mid 3 second 0-100. Not so much from the power perspective... more form the grip perspective.

I am sure the car is mighty quick either way!!

[Orlin]

Thanks for the info Adrian, the car does feel like its moving very fast. The main reason I wanted to get the boost gauge was to test different launch methods and try and improve my 60ft without actually being at the drags so that next time I go there I will be ready. I really did struggle to cut a sub 2 second 60ft time last time I was there. I think I only did it once however I launched always in 1st gear. Perhaps next time ill try the 2nd gear launch and see if my practice will hopefully help get me into the 11s...one day lol. But first ill probably need meth and an LSD

I might try and get my hands on one of those V-box devices in the near future just to compare the two.

[Orlin]

Also I would assume that the Vbox gets its information differently? otherwise it would be a pointless test or am I wrong?

[adrian@vishnu]

All the performance meters use GPS or accelerometers or both. They only get power from the car, and do not use the OBD2 for anything. This is what is used by most of the car magazines. They are not always spot on with an actual drag run as they do not use a "trap" for the trap speed, and give you the actual speed as you cross the finish. But for 0-100 measurement, they are very good. They are not effected by wheelspin and the GPS versions can even tell you the inclination of the road (so no cheating doing it down/up hills).

[Orlin]

Originally Posted by adrian@vishnu

All the performance meters use GPS or accelerometers or both. They only get power from the car, and do not use the OBD2 for anything. This is what is used by most of the car magazines. They are not always spot on with an actual drag run as they do not use a "trap" for the trap speed, and give you the actual speed as you cross the finish. But for 0-100 measurement, they are very good. They are not effected by wheelspin and the GPS versions can even tell you the inclination of the road (so no cheating doing it down/up hills).

Thanks for the explaining that Adrian, I may look into getting a Vbox. Do you know where I can order one? I did a quick google search and it seems there are a many different kinds and that just confused me ever more lol.

[RadiuM]

Originally Posted by MickyD

Call me sceptical, but I find 3.69s to 100km/h very hard to believe for a 1500+ kg car when the Mclaren f1 with 470 odd kw's, and 1150kg's does it in 3.2s.....

yep.. and in second from the start.. W T F!

[Orlin]

I think some of you guys seriously underestimate the ability of the N54. Even if my time is not 100% spot on there are other guys out there who are running mid to high 3s with Vbox so its obviously not impossible

[adrian@vishnu]

I recommend the Performance box. It is full featured and will do lap timing as well at the track (without a beacon using the GPS). It is a great all round product for doing everything.... but it is a bit pricey:

http://www.racerindustries.com/store...roducts_id=613

There are cheaper options without the laptiming etc. But this is the sort of product that is really worth the money if you do track days as well as performance measurement. You can probably get it pretty cheap direct from the USA. This is the defacto standard for club level racers and the "Mexico private road" acceleration tests done on the US forums.

I personally have a full logging dash in my WRX track car. More money, but it logs all car data including engine parameters etc direct from my ECU along with the lap timing etc. Problem is I have to upload the data and analyse it to get the performance results.... mine is better for track use than acceleration tests.

[Orlin]

Originally Posted by adrian@vishnu

I recommend the Performance box. It is full featured and will do lap timing as well at the track (without a beacon using the GPS). It is a great all round product for doing everything.... but it is a bit pricey:

http://www.racerindustries.com/store...roducts_id=613

There are cheaper options without the laptiming etc. But this is the sort of product that is really worth the money if you do track days as well as performance measurement. You can probably get it pretty cheap direct from the USA. This is the defacto standard for club level racers and the "Mexico private road" acceleration tests done on the US forums.

I personally have a full logging dash in my WRX track car. More money, but it logs all car data including engine parameters etc direct from my ECU along with the lap timing etc. Problem is I have to upload the data and analyse it to get the performance results.... mine is better for track use than acceleration tests.

Awesome, Thanks again. It would be good to have the ability to do lap times etc.

[adrian@vishnu]

Originally Posted by Orlin

I think some of you guys seriously underestimate the ability of the N54. Even if my time is not 100% spot on there are other guys out there who are running mid to high 3s with Vbox so its obviously not impossible

It is possible... but only with excellent tyres and a great launch. 100kph is 28m/s. If you accelerate at 1G for 3 seconds you can get to about 29m/s (9.8m/s2). So to get there in 3.5, you have to maintain just under 1G of acceleration, and it takes a very good tyre to do that under acceleration with no aero. So to do 0-100 in 3 seconds, you are accelerating as quick as jumping out of a plane with no air resistance... with air resistance jumping out of a plane, the car would be quicker!!

The N54s with the right mods have the power... but the grip is the problem. But my WRX with AWD is in that range with around 250kW ATW!! Each driven tyre is only accelerating half as much weight!!

[Orlin]

Originally Posted by adrian@vishnu

It is possible... but only with excellent tyres and a great launch. 100kph is 28m/s. If you accelerate at 1G for 3 seconds you can get to about 29m/s (9.8m/s2). So to get there in 3.5, you have to maintain just under 1G of acceleration, and it takes a very good tyre to do that under acceleration with no aero. So to do 0-100 in 3 seconds, you are accelerating as quick as jumping out of a plane with no air resistance... with air resistance jumping out of a plane, the car would be quicker!!

The N54s with the right mods have the power... but the grip is the problem. But my WRX with AWD is in that range with around 250kW ATW!! Each driven tyre is only accelerating half as much weight!!

well meth will be here within the next few weeks hopefully so then ill move onto an lsd and NT555R tyres and call it a day

[adrian@vishnu]

Originally Posted by Orlin

well meth will be here within the next few weeks hopefully so then ill move onto an lsd and NT555R tyres and call it a day

Get some temp into them (burnout), and you should get there!!

[Orlin]

Originally Posted by adrian@vishnu

Get some temp into them (burnout), and you should get there!!

while I am picking your brain, my local shop said to only heat up DRs and not street tyres as you said above get heat into the NT555Rs but will it really not do me much good heating up street tyres like my current yokohama s drives? I think they know their drag stuff as they have a 7 second evo but I just wanted to check with you also.

[adrian@vishnu]

Yep... they are right.

Street tyres are optimised to provide good grip in normal street temperatures. They will actually lose grip when they over heat. You can experience this yourself going to the circuit with street tyres... a couple laps of hard driving around a track and they will overheat, lose grip and tear to bits if you keep going. Some performance oriented street tyres may benefit from a little heat but not much (RE070s etc. which are track oriented street tyres)

Drag tyres are optimised to provide the best grip possible and to do that the compounds they use need good temperature. Then they go really soft (like goo almost... you can dig your finger nails right into it), and really stick to the road. If you don't heat them up you will have no benefit over a street tyre. We had this problem with an N55 DCT at the drags. It is near impossible to do a burnout to get temp into the tyres with this transmission, and as a result we struggled with 2.0+ 60 foot times even with the drag tyres. Don't even bother using drag tyres unless you are going to get them up to temp or you may be worse off than street tyres. Consider fitting a line locker brake kit (disables rear brakes so you can hold fronts only on) to do burnouts also. You want to do a good burnout for several seconds... not just a little spin. This can be done without a line locker kit, but line locker kit makes it easier.

[Orlin]

Originally Posted by adrian@vishnu

Yep... they are right.

Street tyres are optimised to provide good grip in normal street temperatures. They will actually lose grip when they over heat. You can experience this yourself going to the circuit with street tyres... a couple laps of hard driving around a track and they will overheat, lose grip and tear to bits if you keep going. Some performance oriented street tyres may benefit from a little heat but not much (RE070s etc. which are track oriented street tyres)

Drag tyres are optimised to provide the best grip possible and to do that the compounds they use need good temperature. Then they go really soft (like goo almost... you can dig your finger nails right into it), and really stick to the road. If you don't heat them up you will have no benefit over a street tyre. We had this problem with an N55 DCT at the drags. It is near impossible to do a burnout to get temp into the tyres with this transmission, and as a result we struggled with 2.0+ 60 foot times even with the drag tyres. Don't even bother using drag tyres unless you are going to get them up to temp or you may be worse off than street tyres. Consider fitting a line locker brake kit (disables rear brakes so you can hold fronts only on) to do burnouts also. You want to do a good burnout for several seconds... not just a little spin. This can be done without a line locker kit, but line locker kit makes it easier.

you are a wealth of knowledge Adrian! Thanks for the confirmation.

[adrian@vishnu]

No Probs... all the best with your quest for 11s. It is so much more about good launches than power... trap speed is another thing altogeather, and all about power. But if you have a trap speed over 110MPH, an 11 is just a good launch on good tyres away... sounds easy, but it is not!!

[Orlin]

while on the topic of launching...I found an interesting thread here

[Jeef Beef]

Read this thread my drag racing IQ has increased exponentially. Thanks Adrian!

[adrian@vishnu]

Just to be clear... 0-60MPH is 0-96kph, so adds 2-3 tenths for 0-100.

Cutting a 1.8s 60 foot time on the unprepped road with no burnout is a pretty good effort!! I think he runs some Nitto street tyre that is supposed to be good for drag use.

That guy gets some great drag results... he seems to spend alot of time testing and tweaking, and the many little things make a big difference. For his level of mods, nobody else gets close to his results.