Jakob66 E92 M3 Time Trial Build

[jakob66]

Just one lap from the ST3 race on Sunday, finished 4th (I had to slow down a little bit as I was driving on my provisional license and don't want to get that pulled lol...).

Have fun.

[SYT_Shadow]

are you finding the sweet spot in the 3W MCS or not yet?

[dogbone]

Beautiful! Do you have a final weight on the car?

And when you said 18 lbs from the glass----was that 18 lbs just from the front windshield? Or from all the glass?

[kayha12]

Nice work Jens, I was trying to catch your 2:06 for Sunday's TT but only got close! Which I know is not on pace for you haha I know you only ran the morning TT session when it was extremely cold and frosty

[kyippee]

Hey, at 1m:24s of your video, is that bump drafting like my Miata friends rave about? Or is one of the M3s just really trying to get by another?

[jakob66]

Originally Posted by SYT_Shadow

are you finding the sweet spot in the 3W MCS or not yet?

Before the full cage yes, I did a 1:59.3 and was very comfortable.
However, the full cage added weight to the front and made the chassis much much stiffer and the shocks are not right now.
In addition to all the changes my aero tweaks are getting more effective (e.g. modified exhaust so entire car is flat pan) so that the car literally gets pulled down to the track. I need stiffer springs but I'm already on 1200lbs in the rear (divorced system due to 315/30 tires).
I developed an interesting fix to that and will test in May at VIR.

[jakob66]

Originally Posted by kpewpew

Hey, at 1m:24s of your video, is that bump drafting like my Miata friends rave about? Or is one of the M3s just really trying to get by another?

yes , they were 'playing' and took advantage of it lol...

[jakob66]

Originally Posted by dogbone

Beautiful! Do you have a final weight on the car?

And when you said 18 lbs from the glass----was that 18 lbs just from the front windshield? Or from all the glass?

Unfortunately every time I go to BW for dyno testing my car has more power lol.. so in order to keep the 10:1 I'm now on a minimum weight of 3635lbs.
However, the static cross weight is 50%/50% and front rear is 50.5%/49.5%, so pretty good.
The 18lbs is the front windshield only!

[jakob66]

Originally Posted by kayha12

Nice work Jens, I was trying to catch your 2:06 for Sunday's TT but only got close! Which I know is not on pace for you haha I know you only ran the morning TT session when it was extremely cold and frosty

Maybe next time we can have a show and tell session.
Keep pushing!

[dogbone]

Originally Posted by jakob66

Unfortunately every time I go to BW for dyno testing my car has more power lol.. so in order to keep the 10:1 I'm now on a minimum weight of 3635lbs.
However, the static cross weight is 50%/50% and front rear is 50.5%/49.5%, so pretty good.
The 18lbs is the front windshield only!

So, 3635 lbs (car and driver) to maintain 10:1 and stay in TT3? But with all this work you've done to the car, I'm assuming this car could be under 3000 lbs without driver. Add in a 200 lbs driver and you're at 3200 lbs. So did you add like 400+ lbs to the car to stay in TT3? Could you be competitive in TT2 if you took the ballast out and ran the car as light as possible?

[Richbot]

Holy crap that's a lot of lead

[tsk94]

Originally Posted by dogbone

So, 3635 lbs (car and driver) to maintain 10:1 and stay in TT3? But with all this work you've done to the car, I'm assuming this car could be under 3000 lbs without driver. Add in a 200 lbs driver and you're at 3200 lbs. So did you add like 400+ lbs to the car to stay in TT3? Could you be competitive in TT2 if you took the ballast out and ran the car as light as possible?

NASA rules only allow you to add up to 250lbs of ballast. So without the ballast the car must be around 3400 (with driver), at the lightest.

[ThunderMoose]

Originally Posted by dogbone

So, 3635 lbs (car and driver) to maintain 10:1 and stay in TT3? But with all this work you've done to the car, I'm assuming this car could be under 3000 lbs without driver. Add in a 200 lbs driver and you're at 3200 lbs. So did you add like 400+ lbs to the car to stay in TT3? Could you be competitive in TT2 if you took the ballast out and ran the car as light as possible?

TT2 and TT1 are dominated by Corvettes. Jens car optimized to TT2 would give them a heck of a fight, but a Vette optimized to TT2 in the hands of equal driver has shown to outpace pretty much everything out there in those classes.

[kayha12]

10:1 is the base rule for NASA TT3 with there are some things that factor into the adjusted p:w ratio

But if Jens is making say 370whp, and you take the average hp calculation, it should drop about 20 whp or so.

I'm waiting on my dyno guy to give me a printout by RPM so I can take the avg HP and shed some more weight. Currently I am submitted for 362 (peak) hp, and min comp weight of 3510, and actually weighed in at 3525 at 1/4 tank of gas.. I also run 275mm DOT tires so I was able to "get points" for that, which I believe gets offset by having a DCT lol

[jakob66]

Originally Posted by ThunderMoose

TT2 and TT1 are dominated by Corvettes. Jens car optimized to TT2 would give them a heck of a fight, but a Vette optimized to TT2 in the hands of equal driver has shown to outpace pretty much everything out there in those classes.

That's correct!
The E92 M3 is a TT3/ST3 car, we can dance around the 10:1 with different settings.

[jakob66]

Originally Posted by dogbone

So, 3635 lbs (car and driver) to maintain 10:1 and stay in TT3? But with all this work you've done to the car, I'm assuming this car could be under 3000 lbs without driver. Add in a 200 lbs driver and you're at 3200 lbs. So did you add like 400+ lbs to the car to stay in TT3? Could you be competitive in TT2 if you took the ballast out and ran the car as light as possible?

I have The DCT so a penalty of -0.3 applies in ST3. If I stay above 3600lbs a +0.4 applies. My max hp is 384hp, average 367hp. The proper thing to do would be to de-tune the engine with a wider usable rev band but I haven't found that so far. So I offset the weight with downforce to stick with much lighter cars.
I have around 125lbs ballast on board.

To set our E92 M3 to 8.0:1 would require a weight (with driver) of 2990lbs, that's difficult. To do that with a C6 is zero problem plus you have a much lower point of gravity.

[OG Shark]

Are you having to take a penalty for the lexan windshield to run in ST/TT 3?

Modification of the OEM roof line/shape and/or windshield/frame removal -0.3

I tapped my rear view mirror last weekend reaching over to push my passenger side mirror out to get off the trailer... knocked the mirror off and cracked the heck out of my windshield. Would rather replace with lexan instead of glass but it reads to me like its a -0.3 penalty in ST/TT 3 to replace with lexan?

[ThunderMoose]

Originally Posted by jktx

Are you having to take a penalty for the lexan windshield to run in ST/TT 3?

Modification of the OEM roof line/shape and/or windshield/frame removal -0.3

I tapped my rear view mirror last weekend reaching over to push my passenger side mirror out to get off the trailer... knocked the mirror off and cracked the heck out of my windshield. Would rather replace with lexan instead of glass but it reads to me like its a -0.3 penalty in ST/TT 3 to replace with lexan?

I don't think you'd have to take penalty for swap. I think the penalty is for modifying lines.

[OG Shark]

Originally Posted by ThunderMoose

I don't think you'd have to take penalty for swap. I think the penalty is for modifying lines.

That would definitely make more sense... thanks!

[jakob66]

I updated the car's spec to be able to run in ST3 as well. The full cage changed my setup a lot.
Those changes through me off at the beginning of this year due to weight distribution changes and my suspension. However during the last 3 races and TT events I was able to get back on track.
I added more spring in the back, have now a live TPMS system so I can see live tire pressures ( I was in for a surprise!).
The latest event was at VIR last week. Super hot temperatures and very humid...I won both days in TT3 and finished 5th in ST3.

[warp10]

Originally Posted by jakob66

I updated the car's spec to be able to run in ST3 as well. The full cage changed my setup a lot.
Those changes through me off at the beginning of this year due to weight distribution changes and my suspension. However during the last 3 races and TT events I was able to get back on track.
I added more spring in the back, have now a live TPMS system so I can see live tire pressures ( I was in for a surprise!).
The latest event was at VIR last week. Super hot temperatures and very humid...I won both days in TT3 and finished 5th in ST3.

Great lap.

Quick questions

What kill switch are you using and where are you killing the power?

[jakob66]

Originally Posted by warp10

Great lap.

Quick questions

What kill switch are you using and where are you killing the power?

I kill the one going to the MDE and main fuse box in the front.
It kills all power to ignition, injection and the main power to the relay under passenger seat.
There's a 2nd wire from the battery going directly to the starter
but we don't worry about that.
I put the switch right besides the battery. It's the electric switch that BW sells and it works great.