My E90 M3 Dedicated Track build (with pix!)

[Richbot]

kill that exhaust with fire. It’s causjng a vacuum leak

[kyippee]

If you want to keep a valvetronic exhaust, try the Bomiz one. I have it on my car and it has electronic valves, not vacuum-powered. I heard vacuum ones rattle with valves open, while electronic ones don't

[SYT_Shadow]

Originally Posted by dogbone

Yeah I'm glad I went. Definitely want to drive that track again.

Did you run the Quickfit Pro with a stock seat? I have no idea how that stuff works.

So, regarding the limp mode----I looked at it today and I figured out the problem. My car has a valvetronic exhaust. As I mentioned before, I don't know the brand. I don't know if it's a commercially sold product. It might be a custom one-off. I have no idea.

Anyway, in my write up, I said that, as I was leaving for the 3rd session on track, I tried to open the valves of the exhaust but it didn't work. I didn't realize it at the time, but an airline that goes from the engine bay back to the exhaust broke and the silicon tube was dangling under the car. I saw it for the first time when the tow truck driver was putting my car on the flatbed. At the time I didn't even know what the tube was for. As I understand it (and I don't know much about valvetronic exhausts), the air line somehow helps controls the valves. Perhaps someone else could weigh in and share some info about that.

Today, I went and bought a coupler so I could reconnect the broken line. But before connecting it, I did an experiment. First, I started the car and tried to drive. Less than 100 ft later----limp mode. I parked the car back on the driveway, and then installed the coupler. I started the car and drove off without any issues. So, the broken air line was the cause of my limp modes.

What I'd like to know is, why did the line break....is it aging out? Do track speeds somehow create too much pressure in the line? And what do I do from here?.....leave my fix in place? Do I replace the whole line? I don't know. I went to an auto parts store to see if they had the line. They didn't have anything like it and said the tubing is really expensive---like $20-30/ft. Yikes. (They recommended I look into Gates brand tubing.)

So, the car runs again.....the question is do I pursue a more complete fix? We'll see....

Yes, the QuickFit Pro fits on the stock seat. First you install a few metal catches, then after that it connects to your rear seatbelts and those additional spots.
It's a 4 point which allows you to run a Hans, which personally I always want on.
My E92 has the anchoring points installed so I'll shoot a pic tonight an send it to you

It isn't a 6 point with a containment seat but it is a huge upgrade vs stock, much better than CG lock.

Now your limp mode makes sense. There are two valvetronic exhaust tecnologies: electric and vacuum operated.
I have a valvetronic exhaust that's electric because I did not want to mess with the vacuum stuff.

In your case I would replace the tubing, it must have aged and been ready for a replacement. I haven't heard of vacuum type exhausts that die in one track day so I don't think you're dealing with a chronic issue

[dogbone]

Originally Posted by SYT_Shadow

Yes, the QuickFit Pro fits on the stock seat. First you install a few metal catches, then after that it connects to your rear seatbelts and those additional spots.
It's a 4 point which allows you to run a Hans, which personally I always want on.
My E92 has the anchoring points installed so I'll shoot a pic tonight an send it to you

It isn't a 6 point with a containment seat but it is a huge upgrade vs stock, much better than CG lock.

hmmm at the driver meeting, High Plains Raceway said they've started enforcing a rule this year-----no 4-point harnesses. You have to do either seat belts or 5/6-point harness. I called them today to confirm it.

So, 4-point isn't in the cards for me.....Argh.

Would really have liked to try that.

Ugh----the slippery slope of tracking. (I do have a spare Recaro SPG sitting at MiniCorsa in CA.......hahahaha)

[dogbone]

Thanks for the replies regarding the exhaust. For now, I think I'll look into running new tube.....I don't want to replace the exhaust if I can avoid it.

[SYT_Shadow]

Originally Posted by dogbone

hmmm at the driver meeting, High Plains Raceway said they've started enforcing a rule this year-----no 4-point harnesses. You have to do either seat belts or 5/6-point harness. I called them today to confirm it.

So, 4-point isn't in the cards for me.....Argh.

Would really have liked to try that.

Ugh----the slippery slope of tracking. (I do have a spare Recaro SPG sitting at MiniCorsa in CA.......hahahaha)

PCA for example is all about 'no 4 point harnesses'. But they make an exception for the QFP because it is DOT-legal and has antisubmarining tech.

You may still be able to use it

I'd like to only have one seat in the car but PCA doesn't allow it

[admranger]

Not allowing the QFP harness just shows the ignorance of the folks who ban it. Its installation is fool proof vs. putting in 5 or 6 pt harnesses (especially w/o a roll cage).

Show them the sled videos (HMS had them on their site last time I was there -- years ago though).

That being said, go vintage and run the stock 3pt like a boss! I had the 'hug me' bolster seats on my old M3, so that helped.

I lol'd at your first time out on track with the blind corners. My first time out at buttonwillow was an intermediate/advanced student day and I followed along with the lead car. He took off at what to me was a hot first lap on cold tires. I came up on magic mountain for the first time at a pretty good clip and I early the shit out of it...oops. Fortunately it was dry so I just flew across the dirt in my '92 525i and joined up on the short chute before the sweeper. No big deal... If it had been muddy I'd have been in a world of hurt.

[ThunderMoose]

Originally Posted by SYT_Shadow

PCA for example is all about 'no 4 point harnesses'. But they make an exception for the QFP because it is DOT-legal and has antisubmarining tech.

You may still be able to use it

I'd like to only have one seat in the car but PCA doesn't allow it

I am trying to finagle my way into a PCA event with my single seat.

[roastbeef]

now i'm kinda curous... why the one seat rule?

[SYT_Shadow]

Originally Posted by ThunderMoose

I am trying to finagle my way into a PCA event with my single seat.

It's funny that Cup cars seem to be able to run juuuuust fine with only one seat, it is just regular cars that are required to have two seats

If you are in a noninstructed group you should be able to run 1 seat. Perhaps make a rule that if the chief instructor needs to go out with you for an attitude adjustment and you do not have two seats you are disqualified from the event

[dogbone]

Originally Posted by SYT_Shadow

I'd like to only have one seat in the car but PCA doesn't allow it

I'm not aware of this rule. I run with PCA-San Diego once or twice a year. I only have one seat in the car. I've never had any issues.

[SYT_Shadow]

Originally Posted by dogbone

I'm not aware of this rule. I run with PCA-San Diego once or twice a year. I only have one seat in the car. I've never had any issues.

that's only because no one wants to mess with you and your car!

[ThunderMoose]

Originally Posted by SYT_Shadow

that's only because no one wants to mess with you and your car!

I may have a solution

[dogbone]

Originally Posted by admranger

I lol'd at your first time out on track with the blind corners. My first time out at buttonwillow was an intermediate/advanced student day and I followed along with the lead car. He took off at what to me was a hot first lap on cold tires. I came up on magic mountain for the first time at a pretty good clip and I early the shit out of it...oops. Fortunately it was dry so I just flew across the dirt in my '92 525i and joined up on the short chute before the sweeper. No big deal... If it had been muddy I'd have been in a world of hurt.

hehe yeah, the first session was not my finest moment----new track, first time on track with that car. Lots to process. But I think I picked it up fairly quick. I just wish I had more drive time, but the limp modes took care of that.....Ah well, I don't mind leaving hungry so that I have the burn to get back soon!

At Buttonwillow, I've flown off the far side of Phil Hill (Magic Mountain). Luckily it was dry for me too. Worked out ok. I had a pretty crazy moment at that spot once during a Super Lap Battle time attack. First hot lap, I was behind a Lambo Huracan GT3 full blown race car. He zoomed off and was quite a bit ahead of me (that car was doing 1:41s). As I'm rounding Riverside, I'm looking up toward Phil Hill and I see a dirt cloud rising beyond the hill. I'm like.....hmmmm......so I go up to Phil Hill a bit cautiously, and then start braking for the turn and----whooooops----I start sliding and gliding on something slippery. The Lambo had gone up that hill full tilt, hit the slippery stuff and FUUULLLEEWWWWWW off the track. He was like 300 ft out in the weeds. I juuuuust barely kept the car on track because I had been going slower, tippy-toed outta there and headed straight for the paddock. Super Lap Battle is always full of crazy moments.....

[dogbone]

Originally Posted by ThunderMoose

I may have a solution

hahaha what the hell is that?!

If they insist on a second seat, I'm putting this in!!

[okusa]

Originally Posted by dogbone

hahaha what the hell is that?!

If they insist on a second seat, I'm putting this in!!

Do it! That's the one thing your trailer is missing.

[Redd]

Originally Posted by dogbone

Thanks for the replies regarding the exhaust. For now, I think I'll look into running new tube.....I don't want to replace the exhaust if I can avoid it.

Re the exhaust, most valvetronic exhausts actuate the valves using vacuum solenoids. They need a source of vacuum and most of them tap all the way from the brake vacuum pump in the engine bay. If anything happens to this vacuum line which runs all the way from the front of the car to the back, you get a vacuum leak and the associated error codes.

An alternative - without changing your mufflers - is to install a small 12V vacuum pump to provide vacuum source for the exhaust valves. This is what I did. This is the pump I used:

https://www.amazon.com/HELLA-H819530...qid=1553818408

I wired it to ignition (so it starts with the engine) and installed it behind the right side rear wheel well liner. This pump switches itself off when a preset pressure is reached, so it doesn't keep pumping all the time. It fits in there nicely and is protected from water. You can secure it with some double sided tape, the pump is very light. Then run the vacuum line from the pump to electronic solenoid valve for the exhausts.

You're done! Just remember to remove the old vacuum line in the engine bay and blank off the output from the brake vacuum pump (should be a t-joint near the vacuum pump). I've been running this with my valvetronic exhaust for 2 years now with no issues. I did this to isolate and troubleshoot a brake system issue I was having earlier (turned out to be something else) but am I glad I did it.

[dogbone]

Originally Posted by Redd

Re the exhaust, most valvetronic exhausts actuate the valves using vacuum solenoids. They need a source of vacuum and most of them tap all the way from the brake vacuum pump in the engine bay. If anything happens to this vacuum line which runs all the way from the front of the car to the back, you get a vacuum leak and the associated error codes.

An alternative - without changing your mufflers - is to install a small 12V vacuum pump to provide vacuum source for the exhaust valves. This is what I did. This is the pump I used:

https://www.amazon.com/HELLA-H819530...qid=1553818408

I wired it to ignition (so it starts with the engine) and installed it behind the right side rear wheel well liner. This pump switches itself off when a preset pressure is reached, so it doesn't keep pumping all the time. It fits in there nicely and is protected from water. You can secure it with some double sided tape, the pump is very light. Then run the vacuum line from the pump to electronic solenoid valve for the exhausts.

You're done! Just remember to remove the old vacuum line in the engine bay and blank off the output from the brake vacuum pump (should be a t-joint near the vacuum pump). I've been running this with my valvetronic exhaust for 2 years now with no issues. I did this to isolate and troubleshoot a brake system issue I was having earlier (turned out to be something else) but am I glad I did it.

Awesome tip man. Thanks!

[dogbone]

I also got an interesting idea from a shop today for that long vacuum line. They recommended putting a ball valve right at the start of the tubing in the engine bay, so if the line fails at some point, you can just close the valve and the vacuum is maintained. You just can’t open and close the valves until you fix the line, but at least the car will drive normally.

[roastbeef]

there was an interesting scenario in the chit chat thread where someone was running at laguna seca with their valves closed for sound, and their car was going into limp mode because it was choking the car a bit. i don't think you have that problem with sound, but it sounds like these valved exhausts can have some drama.

[kyippee]

I think it may have been an earlier prototype design of the Bomiz muffler. Hoping the production version I have doesn't have that issue.. will be trying closed.

[Redd]

Originally Posted by roastbeef

there was an interesting scenario in the chit chat thread where someone was running at laguna seca with their valves closed for sound, and their car was going into limp mode because it was choking the car a bit. i don't think you have that problem with sound, but it sounds like these valved exhausts can have some drama.

Yes I have been informed that can happen. Was told to close the valve purely for noise purposes and not to do high rpms with the valve closed.