BMW 1 Series Australian Drag Racing Standings

[BMW86]

Originally Posted by JB4135

Well done Vinney. Nice time mate.. Good to see the meth is flowing well for you. What additive were you running? That 11 second barrier is alot harder than it seems even with meth and LSD.

Good to see that looooooooooong list of mods finally in your sig.

11s is a tough one to crack! I think changing back to my old wheel/tyre setup should see an improvement though as I spun really bad all the way through 1st! The car was shuddering really bad and on a couple runs my car stepped out really bad sideways. I mixed up my additives a lot but mostly around 40-45. I think I was the quickest car on the night until a fully prepped track ute came in at the end and smoked me both times! They happened to be some of my worst runs too! He pulled an 11.7@117mph. I have a blast when I go out to the drags, I got asked about my car more times than ever last night but people were still asking me if it's a 4 or a 6!!!

Yes I updated my sig, seems to be the trend here. I had to leave a couple small things out because it exceeds the word limit though

[JB4-335]

40-45 additive....... that's why you didn't crack an 11. Put it on 60 Additive with some better rubber and hold on. I reduce boost and cap it to about 13-14psi in 1st. That's how I've got my Aussie 1 addicts 60' record.

[BMW86]

Originally Posted by JB4135

40-45 additive....... that's why you didn't crack an 11. Put it on 60 Additive with some better rubber and hold on. I reduce boost and cap it to about 13-14psi in 1st. That's how I've got my Aussie 1 addicts 60' record.

I experimented with higher additives as well but was mostly in the 40-45 range.

I also changed max boost to 11psi in 1st gear. I can only seem to launch at 1700rpm.

I think my problem is the wheels/tyres and I let my tyre pressure down far too low. We got there fairly late in the evening so I didn't have time pump them back up again as they closed up early that night.

[JB4-335]

Originally Posted by BMW86

I experimented with higher additives as well but was mostly in the 40-45 range.

I also changed max boost to 11psi in 1st gear. I can only seem to launch at 1700rpm.

I think my problem is the wheels/tyres and I let my tyre pressure down far too low. We got there fairly late in the evening so I didn't have time pump them back up again as they closed up early that night.

Cool. Race fuel time!
I drop my tyre pressure between 16-18psi.

[BBK]

Surprising you still managed a 12.17 with a 60ft of 1.8 but only 113mph Vin. It took a 1.760ft and 114.9mph for me to do 12.1

I think those wheels are the biggest problem? Maybe even your hard suspension, is it possible to soften the rear? I found it near impossible to lose traction in 1st gear, are you doing a burnout?

[BMW86]

Originally Posted by JB4135

Cool. Race fuel time!
I drop my tyre pressure between 16-18psi.

My tyres didn't feel too great the lower I went, I think I will start close to full psi and work my way down

Originally Posted by BBK

Surprising you still managed a 12.17 with a 60ft of 1.8 but only 113mph Vin. It took a 1.760ft and 114.9mph for me to do 12.1

I think those wheels are the biggest problem? Maybe even your hard suspension, is it possible to soften the rear? I found it near impossible to lose traction in 1st gear, are you doing a burnout?

Yes, happy with the time considering the power I was making. With the LSD, I still spin, except the only difference is both tyres are spinning. I think running the previous wheel/tyre setup and softening the rear is a good start. I did a burnout on 2 runs and it didn't make any noticeable difference.

[BBK]

DCI or stock?

[MrBlonde]

You don't want to soften the rear suspension. When the rear squats you will lose contact patch.

[BMW86]

Originally Posted by BBK

DCI or stock?

DCI. I actually think it's slowing me down, car feels sluggish in this hot weather. I also think it will be harder for everyone to break 11s in this heat as opposed to winter. I mentioned the DCI possibly slowing me down to Terry and he did not respond I may switch back to stock or try the Mr5

Originally Posted by MrBlonde

You don't want to soften the rear suspension. When the rear squats you will lose contact patch.

What is your recommendation Kenny? Should I keep it the way it is? My car is pretty stiff at the moment, there is no give in it!

[MrBlonde]

Originally Posted by BMW86

What is your recommendation Kenny? Should I keep it the way it is? My car is pretty stiff at the moment, there is no give in it!

What are you running?

+ Transmission
+ Diff (and ratio)
+ Suspension
+ Wheels
+ Rubber (and pressure)

And what trap speeds are you getting? What 60' times? Average? Best to date?

[BBK]

Originally Posted by MrBlonde

You don't want to soften the rear suspension. When the rear squats you will lose contact patch.

Interesting, I would have thought the weight transfer to the rear would be better with more travel/softer suspension?

But I can see how the contact would be reduced too.

I think the biggest thing is tyre choice.

[MrBlonde]

Originally Posted by BBK

Interesting, I would have thought the weight transfer to the rear would be better with more travel/softer suspension?

And you would be wrong. That's how it works with 70s muscle cars with live axles. With IRS the weight transfer and soft rear suspension will cause the IRS to squat towards the ground, lifting the tyres up off the track at the outside edges. You now have far less rubber contacting the track and therefore you reduce traction significantly.

With a live axle the weight throwing to the rear of the car and soft suspension drives the tyres harder and harder into the track, maximising traction (and lifting the front wheels!).

Different beasts totally live - IRS.

[MrBlonde]

Originally Posted by BBK

I think the biggest thing is tyre choice.

With our cars, they are heavy street sedans with very poor chassis and underpowered BUT we have tiny narrow tyres. This means a big challenge to get them out of the hole.

The solution has to be a combination of rubber, wheels, suspension and transmission ... plus computer assistance.

[BMW86]

Originally Posted by MrBlonde

What are you running?

+ Transmission
+ Diff (and ratio)
+ Suspension
+ Wheels
+ Rubber (and pressure)

And what trap speeds are you getting? What 60' times? Average? Best to date?

Stock Trans
Wavetrack LSD (not sure of ratio)
KW V2 + M3 sway
SF71 19 inch
Michelin PSS 225/35/19 265/30/19 - 30 fronts 20 rears

Traps range between 113-115 during last visit. 60ft range between 1.8-2.0

[MrBlonde]

Originally Posted by BMW86

Stock Trans
Wavetrack LSD (not sure of ratio)
KW V2 + M3 sway
SF71 19 inch
Michelin PSS 225/35/19 265/30/19 - 30 fronts 20 rears

Traps range between 113-115 during last visit. 60ft range between 1.8-2.0

+ Automatic tranny (great for drag racing) with LSD so you're good to go there
+ Coilovers - You can look at firming up the rear by fitting much stiffer springs to the KWs
+ Suspension - You can look at replacing all bushings with solid alloy
+ Ditch the 19" wheels for drag racing, they are shit. Go with Kosei K1-Racing 17" and the Hoosiers to suit (as documented elsewhere)

Should give you potential for 1.6 short time. Will carve at least half a second off your ET with same power.

[BBK]

Originally Posted by MrBlonde

With our cars, they are heavy street sedans with very poor chassis and underpowered BUT we have tiny narrow tyres. This means a big challenge to get them out of the hole.

The solution has to be a combination of rubber, wheels, suspension and transmission ... plus computer assistance.

True, and as for the IRS/Live axle, you learn something new every day! Didn't think of that...

Interesting that 2/3 of the cars that can do 1.7** 60ft times are using stock wheels and no LSD

[JB4-335]

That's cause were great drivers Richard.

[JB4-335]

Just let me know when you guys need a lesson in achieving a good 60'. I call it "How to get the POWER down". It's a novel based on a true story about a heavy vert.

[JB4-335]

Originally Posted by ianf2002

this drag stuff seems complicated stuff ... i'd like to come and watch sometime.

Don't worry Ian I'll be more than happy to have a crack at the 1/4 mile with your 1M.

[BBK]

Pfft, we all know it's the Turbosmart BOV's that are giving you the edge!

[JB4-335]

Originally Posted by BBK

Pfft, we all know it's the Turbosmart BOV's that are giving you the edge!

Lol!! Kenny knows that but still refuses to but them on.

[BBK]

Nah Kenny just can't drive a manual :-p