BMS update

[Tom C]

Originally Posted by gmd2003

Several people have gotten 1.7x 60 ft a 1.6x and only hit 128 mph , one with meth and race gas in ( hot weather) . Wheel spin hurts ET wayyyy more than trap though , hooking up 100% actually lowers trap with most cars . Even with 1.9-2.1 60ft on my test road with PSS I'm hitting 130mph terminal speed ( 11.4-11.6 ET ). That should be > 128x trap as well. I in know way think I have 700 hp much less 800 and I have a M6 CP , SS DP's , Akra , and Gruppe M with a BMS running + 3.5 on 93 octane .

Wheel spin hurts ET more than traps but I respectfully disagree on the "hooking up 100% actually lowers trap with most cars" assertion. The hooking up 100% part usually entails switching to a drag radial. There are a few things to consider:

1. The drag radials sometimes have lower tire height than OEM and change the effective gear ratio (shorter) and may cause an extra shift which could lower trap speed.

2. Most people lower the tire pressure (wholly appropriate) for drag radials to 10-15psi. This increases the contact patch and increases the rolling resistance which is great for getting off the liine quick but could have a negative impact as speeds increase above 100mph.

3. The quicker ETs are usually when the track is hot and sticky and the tires are hot...but higher trap speeds will increase in colder air and when the car is properly cooled down (but not cold)...so weather, track and engine conditions can all play a huge part on the tension between great traps and great ETs. You have to make sure it is an apples to apples comparison and it is nearly impossible to keep all the variables equal to prove that out.

I have kind of studied this issue when I had my GT-R. That car was SO efficient getting down the track. If all things are equal (no change in tire inflation/size, engine temps and shifting), the more efficient you are at putting power down during the run, the HIGHER the trap speed. When you are efficient getting out of the hole it allows for more of the remaining 1/4 mile to be available to build speed. I would suggest that the lower trap speeds you alluded to were a product of some other outside influence.

[ImpetuousRacer]

Definitely feel the difference with the BMS. I'm at stock setting with 95 octane. It seems MDM is way more invasive now. Maybe even more that it needs to be. Do you guys get better results with MDM off and feathering it? Havent had a chance to get on a good road and drive time to test. Thanks.

[PetrolFumes]

Originally Posted by ImpetuousRacer

Definitely feel the difference with the BMS. I'm at stock setting with 95 octane. It seems MDM is way more invasive now. Maybe even more that it needs to be. Do you guys get better results with MDM off and feathering it? Havent had a chance to get on a good road and drive time to test. Thanks.

Curious about where people are getting higher than 93 octane. Not at a regular gas station?

[Fantasm]

Some regular gas stations carry VP or Sunoco...

[wrsbmw]

Originally Posted by Fantasm

Some regular gas stations carry VP or Sunoco...

Not in Texas.

[greentrbo95gst]

Originally Posted by Tom C

Wheel spin hurts ET more than traps but I respectfully disagree on the "hooking up 100% actually lowers trap with most cars" assertion. The hooking up 100% part usually entails switching to a drag radial. There are a few things to consider:

1. The drag radials sometimes have lower tire height than OEM and change the effective gear ratio (shorter) and may cause an extra shift which could lower trap speed.

2. Most people lower the tire pressure (wholly appropriate) for drag radials to 10-15psi. This increases the contact patch and increases the rolling resistance which is great for getting off the liine quick but could have a negative impact as speeds increase above 100mph.

3. The quicker ETs are usually when the track is hot and sticky and the tires are hot...but higher trap speeds will increase in colder air and when the car is properly cooled down (but not cold)...so weather, track and engine conditions can all play a huge part on the tension between great traps and great ETs. You have to make sure it is an apples to apples comparison and it is nearly impossible to keep all the variables equal to prove that out.

I have kind of studied this issue when I had my GT-R. That car was SO efficient getting down the track. If all things are equal (no change in tire inflation/size, engine temps and shifting), the more efficient you are at putting power down during the run, the HIGHER the trap speed. When you are efficient getting out of the hole it allows for more of the remaining 1/4 mile to be available to build speed. I would suggest that the lower trap speeds you alluded to were a product of some other outside influence.

My best pass was with catless dp's, exhaust and BMS set to +3 on a mixture of 91 and 100 octane. The car is very picky and unpredictable. It's almost impossible to have the same pass twice in a row. The car not only heat soaks really bad, but also the launch technique is close to impossible to repeat. I have done many runs with stock tires and drag radials and it's tough to perfect the car, but possible.
With the heavy weight of our cars even with drag radials you can't go below 20psi as the rear will dance all over the track. Tried it.

[ImpetuousRacer]

Originally Posted by MPowerrF10

Curious about where people are getting higher than 93 octane. Not at a regular gas station?

Once in a while there is a place that has it at the pump randomly, but they always seem to go out of business.

I found a place called Tom's Thumb, they have 95 and 100 at the pump, hand wash and regular car wash, market, wine bar, and BBQ restaurant inside...
http://www.tomsthumbfreshmarket.com/

It's actually close to my house.

[PetrolFumes]

Originally Posted by ImpetuousRacer

Once in a while there is a place that has it at the pump randomly, but they always seem to go out of business.

I found a place called Tom's Thumb, they have 95 and 100 at the pump, hand wash and regular car wash, market and BBQ restaurant inside...
http://www.tomsthumbfreshmarket.com/

It's actually close to my house.

Definitely wont see anything like that in nj

[(H)]

Ok, I filled up 1/4 93 and 3/4 e85 today. Runs smooth but I am not sure about the JB4 settings that I should apply. Any insights?

[PetrolFumes]

Originally Posted by r33

Been using BMS Stage 1, then upgraded to Stage 2 on both of my car. Combined miles 30k.
I got so impressed with the product, I decided to became a reseller.
Also, had a great experience first hand last week with the M4 setup. I got a chance to drove the car before and after the JB4. It was night and day, butt dyno was 500+ whp, and it was proven by someone's dyno running the same setup.

Theres a stage 2 for our cars?

[r33_RGSport]

No, I was answering the question just in generic answers.

see my post.
http://f10.m5post.com/forums/showpos...0&postcount=21