E92 M3 Time Trial build

[tlrid3r]

Great write. Thanks for sharing. Do you think you can remove the stock header and reinstall with out dropping subframe. To replace gasket.

[Greg S]

Before the first TT3 event we needed to drop as much weight as we easily could. We had already lost 43lbs from the exhaust, but we needed to lose another 372lbs to get to our minimum competition weight of 3335 lbs, that probably wasn’t going to happen so we would take what we could easily remove. We were somewhat short on time so we removed the trunk carpet and sides, rear carpet section, rear seat(bottom, back, and side bolsters), rear center console, and a few other bits and pieces. We also removed both front seats and replaced just the driver’s seat with a Cobra Suzuka. In a future post I’ll go over the weight saving of the various bits, but this got our weight down to 3460lbs, meaning an approximate weight loss of 250lbs from the rear interior. Note that the passenger seat had been reinstalled when these photos were taken.


NASA MSR Houston September 26-27th was the first event for me to compete in NASA TT3. I entered this event with the 366 WHP(before I had re-dynoed at 376WHP) dyno giving me a minimum weight of 3335lbs. I arrived Thursday night with the intention of getting a decent parking spot with no plans of doing the Friday test day. But once lunch rolled around on Friday I talked myself into doing the test day, it was only $75 afterall. I managed to borrow some high heat cycle 275/35/18 Hoosier R7’s so I was able to get a few sessions in to learn the track, I had only been on MSR Houston once previously several years earlier going the opposite direction. Photo taken before Hoosier contingency stickers were applied


Saturday rolled around and I used the old R7’s for the practice session which set my grid position at 6th overall, 1st in TT3, with a 1:43.7. I put on the Sticker A7’s for session 1 and did a 1:40.314 on my 3rd lap after having to back off during my second hot lap due to traffic. I pulled off and was weighed at impound at 3460 lbs, 125lbs overweight. This beat the old TT3 lap record of 1:41.457 held by Terry Fair in his Mustang by 1.1 seconds. However, after looking back at my data, my best rolling lap was a 1:39.323, it was a mixture of my first and second lap where I had to back off for traffic. I went out the next sessions to see if I could best my lap which I couldn’t, running a 1:41.1, I then parked it for the final session. I finished 1st of 7 in TT3 for Saturday.

It rained Saturday night and most of the day Sunday, I didn’t go out the first session. I went out for session 2, it was still pretty wet, I just wanted to get an idea of the wet line in case it was going to be wet all day. For session 3 I made a bad call and went out on Hoosier H2O’s which I knew was a bad call as I was driving up to grid, but I didn’t think we’d have time to swap tires and make it back up to grid in time and keep my grid position. I went out and got in 1 flyer lap, a 1:46.1, and pulled in and came back to the paddock to swap A7’s back on. The tricky part of this is if I were to go back out and not get a timed lap in before the checkered, my times would’ve been DQ’ed and another car had gone faster than me at a 1:45.1. With the forecast being questionable for the final session I decided to gamble. We were able to gets the tires swapped quickly and get back out up to grid and out on track. I knew I needed to get up to speed as soon possible and as long as I crossed start/finish with no checkered flag waving I’d be good to get a flyer lap in. Fortunately the checkered wasn’t waving yet by the time I made it around to start/finish and I was able to do a 1:41.5 on my one hot lap which ended with the checkered flag. The sun decided to come out for the final session, I was hoping for a 1:39 with the cooler weather, but with the track being green I could only pull off a 1:40.6 which was good for 1st of 5 for Sunday. Thanks to Hoosier tire contingency I was able to win 4 Hoosiers. Did I mention that these Hoosiers are sticky?


Three weeks later was NASA Texas World Speedway October 17-18th, I had received the Hoosiers I had won and mounted them up, but the plan was to run on old tires if I could win on them. I entered this event with the newer 376WHP dyno and a minimum weight of 3401 lbs. This was the final NASA event of the year and I had set a goal of running a 1:48, Terry Fair held the track record at a 1:49.926. I arrived to the track Thursday night but didn’t do the test day as I didn’t want to use up my tires and I’ve got quite a bit of time at TWS. I managed to run a 1:50.6 in warm up gridding me at 4th overall and 1st in TT3. In session 1 I did a 1:51.1 on my first lap, on lap 2 I was pushing the limits of braking into T1 and went straight off, under control, near turn in for T2. I took the long way around and rejoined the track after T2 after I let most everyone by. Your TT times are DQ’ed for a session if you go 4 off or spin, so I parked the car once I made my way back around to the pits/paddock . Peter Chang was there in his very well prepared E46 M3 that I built a few years ago, he pulled off a 1:49.2 in that session, I knew I had my work cut out for me. I had my sticker set of tires, but with the track and ambient temps(80*) rising I really didn’t think I had it in me to beat him. I could use them now or save them for Sunday morning when the track would be at its best, but I would basically be resigning to second place… I didn’t like that idea. I decided to gamble and put on the sticker Hoosiers for Session 2, my 1st and/or 2nd laps were my best chance at going faster than a 1:49.2. I was gridded behind a Wolf GB08 which is a small prototype like vehicle running TTU. On the out lap I gave myself some space behind him, but I figured he’d run away from me pretty quick. Unfortunately by T1/2 I was on his tail, but he was aware and pointed me by to the inside of T2 at exit, compromising my exit a little. The rest of the lap was open track and I managed a 1:49.057, which honestly surprised me, but also teased me by being so close to a 1:48. I was weighed after this session at 3501 lbs, 100 lbs overweight, poor planning on my part by showing up with a full fuel tank. Peter Chang didn’t go out for this session and we both parked it for the final session 3. My 1:49.057 was good for 1st of 10 in TT3 and lowered the track record by .9 seconds. I later looked at data and saw my best rolling lap was a 1:48.797, I lost about .25 seconds due to the pass at exit of T2.

Sunday morning I was hoping to dip into the 1:48’s with the cooler weather but I felt like the track wasn’t as grippy as the day before(I’m not sure if anyone else felt the same way) and only pulled off a 1:50.121, Peter Chang was at a 1:52.0. In session 2 I did a 1:50.6 and Peter didn’t go out. I was ready to park the car for the day but I saw Peter was going out for session 3 which had me worried, so I went out and did a 1:51.2 and Peter did a 1:53.1, the track wasn’t getting any faster. I parked the car for the final session and began loading, my time from session 1 held up and I finished 1st of 9 in TT3 and won another set of Hoosiers.



TWS was the final NASA event for 2015, the original plan was to wait a while until I did aero, but I wasn’t comfortable by only winning by .2 seconds, so for the next NASA event we’ll be sporting some aero upgrades. There’s supposed to be a 2016 rules update for TT3/ST3 released next week, so we’re waiting for that to be posted before we do anything too drastic, there are talks of raising the class multiplier from 9.0 to something higher.

Other near future plans are to install a full AiM data and video system as we’ve only been using an AiM Solo and we want to have the capability of logging a lot more data, specifically temperatures so we can get an idea of what cooling upgrades will be necessary once this is converted to wheel to wheel and needs to be able to sustain race pace for 45 minutes. We’ll also fabricate a weld in roll bar, install a Schroth 6 point harnesses, a fire system, and a few other small touches, but it should be 2-3 second a lap faster at that point, track dependent. The next NASA event is at MSR Houston January 23-24th, so we’ve got quite a bit of time to plan, build, and hopefully test.

[Greg S]

Originally Posted by warp10

this is great. what are you impressions of the bimmerworld pieces? they are next on my build list

Originally Posted by jakob66

Greg
Nice work and really smart job with the exhaust! Cutting 42.9 lbs from behind the rear axle is the way to go. That thing will turn! What battery do you have?

I'm in progress installing the front BW arm conversion myself but have some issues with the larger drop of my KW CS (vs. your MCS) and ergo with the lower control arm rode end on the wheel side. As of now I can only install once I compress the shocks.

Originally Posted by m3SennA

do you mind sharing your thoughts on bimmerworld suspension parts?

The BimmerWorld arms have quality rod ends and good range of adjustment. Locking down the jam nuts can be tricky on some of the arms in the rear suspension.

As Jakob66 pointed out, the BimmerWorld front race control arms can have an issue with droop travel, even with off the shelf MCS dampers, although MCS can limit the droop travel. SPL has a front control arm in the works that helps with this, send me a PM if you want some info about them.

Originally Posted by SYT_Shadow

A reason for the really low initial dyno is the old software. If you update to oem software you get 20hp more.
Apparently you should update to the latest software before getting a tune.

The car had up to date software on it, 240E.

Originally Posted by ///Mobbin

Awesome build, thanks for sharing!

I'm curious if you ever go out with Driver's Edge? I'll be at TWS in less than two weeks with them.

Thanks, I don't have any TDE events planned, but I'll probably make it out to some next year.

Originally Posted by lutfy

Good work Greg! Car sounds awesome! Sold the E46 JP? Saw Thomas/Garrity LTW in your pic is he tracking that car now?

Build related question: why did you go all out on power initially rather than stripping the car down and baselining. For instance headers would be the last thing to install no?

I sold the JP/GTS2 E46 around 5 years back. Yup, that's Garrity's LTW, he's tracked it some.

I knew I'd have to make the power to get near the TT3 limit without having to remove AC, radio, sound deadening, and any other creature comforts. I didn't really have the time to do it step by step with dynos as I had originally wanted. Also, who wants to just leave all those parts on the shelf?

Originally Posted by nicksm3

This is such a great write up! I actually responded to you on FB about the 10.5 square setup. I would love to hear the exhaust setup. Are are the BW suspension components..I may opt for them

There's a video clip in post #11.

Originally Posted by tlrid3r

Great write. Thanks for sharing. Do you think you can remove the stock header and reinstall with out dropping subframe. To replace gasket.

I don't think that would be possible, but the front subframe lowers pretty easily in these cars.

[Rassilon]

Awesome write up!I don't see any swaybar upgrades in your parr list, hlw do you feel about the stock sway bars? Are they a good match with square tires?

[tlrid3r]

Thanks for the response

[Greg S]

Originally Posted by edwardgtxy

Awesome write up!I don't see any swaybar upgrades in your parr list, hlw do you feel about the stock sway bars? Are they a good match with square tires?

Still on stock sway bars, although we need to try disconnecting the rear bar to see if it can get the car to put down power better on exit. With street tires and ~310WHP the stock differential wasn't a problem, but with more power and better tires the car really struggles to put power down. A Diffsonline unit with a shorter ratio is probably in the future, but for now we need to work the dampers, springs, and swaybar to get it to hook up.

We need to experiment with the above and hopefully removing the rear sway bar works like I believe it should(and the additional weight loss), at that point we'd like to have an adjustable front sway bar for fine tuning.

[Greg S]

Originally Posted by M3 Number 86

that brake kit though......

Originally Posted by SYT_Shadow

I have the same one. It is incredible, it has the most massive pads you can imagine

Definitely the way to go for a serious track car

Originally Posted by M3 Number 86

yeah looks serious!

Some photos of an older install of the same PFC Z54 big brake kit, 8.4 lbs of weight savings with the calipers, and 5.2 lbs of weight savings with the rotors, for a total of 13.6 lbs of unsprung weight.




Comparison of pad volume

[///Mobbin]

Pad thickness is insane, thanks for sharing! I also wanted to ask, what are the dimensions on the PFC rotors that come with this kit?

[///Mobbin]

Also, what ratio are you thinking on the diff?

I have the Dinan 3.45 installed on my DCT car, though I believe it's no longer available. Dinan told me that they used to source the gears from BMW Motorsport and this particular set is no longer made.

[Greg S]

Originally Posted by ///Mobbin

Pad thickness is insane, thanks for sharing! I also wanted to ask, what are the dimensions on the PFC rotors that come with this kit?

378mm diameter, I'm not positive on thickness, but it looks like 31mm. I should also note I'm not running any front brake ducting and I haven't noticed any fade.

Originally Posted by ///Mobbin

Also, what ratio are you thinking on the diff?

I have the Dinan 3.45 installed on my DCT car, though I believe it's no longer available. Dinan told me that they used to source the gears from BMW Motorsport and this particular set is no longer made.

I'm thinking of as aggressive as a 3.85, but I haven't put a ton of thought into it.

[///Mobbin]

Originally Posted by Greg S

378mm diameter, I'm not positive on thickness, but it looks like 31mm. I should also note I'm not running any front brake ducting and I haven't noticed any fade.

I'm thinking of as aggressive as a 3.85, but I haven't put a ton of thought into it.

Awesome that the PFC's are setting records out there and not fading on you, even w/o ducting. And nice on the diff, keep us posted!

[Greg S]

Originally Posted by ///Mobbin

Awesome that the PFC's are setting records out there and not fading on you, even w/o ducting. And nice on the diff, keep us posted!

PFC isn't new to the race market, although their street offerings are relatively new. PFC is now Porsche Motorsport's brake supplier and they're also the brake supplier for the M235i. The Z54 kit really is huge bang for the buck, you're getting motorsport level parts at street kit pricing.

[AP3X_FTW]

Very nice build here, subscribed!

I may have missed it, but are you going to leave the rear OEM calipers with PFC 11 pads?

[Greg S]

Originally Posted by AP3X_FTW

Very nice build here, subscribed!

I may have missed it, but are you going to leave the rear OEM calipers with PFC 11 pads?

Correct, OEM rear calipers with PFC 11's.

[AP3X_FTW]

Originally Posted by Greg S

Correct, OEM rear calipers with PFC 11's.

Right on... and you are happy with the way the car responds in heavy braking zones and/or under consistent lapping with just the front BBK? I know this kit is the business, more so curious about running just a front kit vs all four corners. Certainly is more cost effective.

[warp10]

yeah I run just a front kit as well. car is still very balanced and the stopping power is incredible. I am running the Stoptech 380's.

[AP3X_FTW]

Originally Posted by warp10

yeah I run just a front kit as well. car is still very balanced and the stopping power is incredible. I am running the Stoptech 380's.

Good to know!

[ortho281]

Great write up! This build is an inspiration! Your blistering times is proof of how well your car is set up. Looking forward to seeing you at the track again.

[Greg S]

A bit of an update, we have a few projects on the time trial car going on over the winter, and the first event is only 4 weeks away and fast approaching. We stripped out the remainder of the rear interior such as the rear side/”door” panels, some sound deadening, and the speaker shelf speakers and covering. The head liner was removed to allow the roll bar to be as high as possible, but will be reinstalled in two pieces once the roll bar is finished. The car will also be retaining the side curtain airbags. We will eventually be replacing the rear trunk floor with most likely a bead rolled aluminum floor.

The original plan for the roll bar was to leave the roof bow in place as the tubing fits in it perfectly, however, we had to cut it out in order to get complete welds during the fabrication process. The roof bow weighs in at 2.8 lbs and provides some structural rigidity for pressure on the roof, but not a significant amount for the overall torsional rigidity of the car, especially when you see how flimsy the attachment tabs are.

Next up is something you usually only see removed on some fully caged race cars and not cars with just a roll bar.

As you can see the bulkhead weighs in at 13.0 lbs. This is usually only something we would recommend removing on a caged race car, but with the roll bar tying into multiple points and picking up the load path from the rear shock mount(remember this car runs a true rear coilover) we don’t feel we’ll be losing any significant torsional rigidity with its removal. It also gives the interior a much cleaner appearance.

Here’s the main hoop getting ready to be welded outside of the car. The driver’s seat was also lowered about an inch before roll bar mockup to get the harness bar at the proper height(we prefer 0-5* down from shoulder/Hans to tube).


The AiM dash, SmartyCam, and aero all still remain to be installed. I won’t be going into too much detail about the aero until after our first event, but it will be something you’ll want to keep your eye on.

[ortho281]

Very nice! Looking forward to more updates!

[jakob66]

Originally Posted by Greg S

I won’t be going into too much detail about the aero until after our first event, but it will be something you’ll want to keep your eye on.

I guess we will see a 'modified exhaust' with your new aero kit?

Do you think we can depressurize the cabin (open windows!) with the trunk plastic floor removed? That should work.
Cheers
.
.

[Greg S]

Originally Posted by jakob66

I guess we will see a 'modified exhaust' with your new aero kit?

Do you think we can depressurize the cabin (open windows!) with the trunk plastic floor removed? That should work.
Cheers

You're on the right track, but that will be a bit further down the line.

The cabin is usually a low pressure zone with the windows down, not a high pressure zone. With the exhaust exiting right near the trunk floor it needs to be well sealed to keep the fumes out.