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      02-05-2012, 02:43 PM   #1
paradocs98
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Looking for E90 seat/harness options

I'm about to give up on the Schroth QuickFit Pro harnesses for our cars this season. I'm not really interested in the Rallyes as a substitute.

I'm now wondering if it would work to install fixed-back Recaros, Sparcos, Racetechs, etc., and then use the QuickFit Pro with those seats. Since the E92/E90 harnesses are on indefinite hold, would an E46-spec QuickFit Pro work in our cars with a fixed-back racing seat?

I know that a full 5- or 6-point harness would be more ideal with dedicated race seats, but my car is a daily-driver sedan that normally holds child seats in the back, so a rollbar or half-cage is not possible. I did see a guy at NJMP who had a custom-fabricated harness bar in his 335xi sedan that mounted to the B pillars and had a removable center section for "normal"/domestic daily driver-mode. But I would worry about the strength and integrity of that harness bar given that it is segmented/removable and not fixed...

Any thoughts? Has anyone in a similar situation come up with a solution?
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      02-05-2012, 04:29 PM   #2
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Hey Paradocs,

From experience I'd go with something like the Recaro Profi XL. This seat comes standard in the M3 GTS and I believe is one of the most comfortable dual purpose seats out there. I ran this in my E90 as well as my GTR. Great seat for the money and very easy to use with 6 point harnesses and hans device.

For what you use the car for I'd suggest getting a harness bar that allows you the safety of running harnesses properly. One of these harness bars will be plenty strong for what you need it do to.

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      02-05-2012, 04:33 PM   #3
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Thanks for the reply, Martin. Are there known and proven harness bars out there for the E90, or do I need to pursue a local custom fabrication option? What did you use in your E90?
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      02-05-2012, 04:45 PM   #4
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Quote:
Originally Posted by paradocs98 View Post
Thanks for the reply, Martin. Are there known and proven harness bars out there for the E90, or do I need to pursue a local custom fabrication option? What did you use in your E90?
I have seen harness bars by AE Performance and FMU (Fluid Motor Union). I used the AE bar in my E90 (sorry, no photos).

EAS or VAC make sub harness mounting plates...

EAS also makes all of the Macht Schnell pieces to bolt the seat into the E90 with ease. Make sure to get the occupancy deleter from there to remove the airbag light.
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      02-05-2012, 11:03 PM   #5
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Hi Jason,

I would recommend trying out fixed-back seats first, you'd be surprized about how much better they hold your body on the track.

Obviously it would be ideal to have a 6 point harness installed, but I would rather do it properly, e.g. mounting all the straps to the frame or roll structure of the car, rather than attempting a half-assed solution for convenience. I've seen too many roll/harness bars which make absolutely no sense from a structural standpoint.

Here are a few pictures from Ralf's GT4 showing how the lap and anti-submarine straps are mounted onto the reinforcement plates on the frame of the car.

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      02-05-2012, 11:13 PM   #6
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Richard, that is a good solution but most owners do not want to drill into the car.
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      02-06-2012, 07:19 AM   #7
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Quote:
Originally Posted by Richard@M-World View Post
Hi Jason,

I would recommend trying out fixed-back seats first, you'd be surprized about how much better they hold your body on the track.

Obviously it would be ideal to have a 6 point harness installed, but I would rather do it properly, e.g. mounting all the straps to the frame or roll structure of the car, rather than attempting a half-assed solution for convenience. I've seen too many roll/harness bars which make absolutely no sense from a structural standpoint.

Here are a few pictures from Ralf's GT4 showing how the lap and anti-submarine straps are mounted onto the reinforcement plates on the frame of the car.

Attachment 640693

Attachment 640694

Attachment 640695
Do you have zoomed out photos...I am not sure what I am looking at there!
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      02-06-2012, 09:03 AM   #8
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I was just looking at all of the Macht Schnell seat brackets and mounting equipment on EAS's site. The anti-submarine strap bracket and bolt-on lap belt brackets for a 6-point harness attach to the Macht Schnell seat-mounting floor brackets. So would this be less than ideal, based on what Richard is saying? You would be depending on the strength/integrity of the two seat-mounting floor brackets for the whole shebang, other than the shoulder belts mounted to a harness bar...
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      02-06-2012, 09:17 AM   #9
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If the goal is staying put in the seat, www.cg-lock.com spend $60 or whatever and use the stock belts, and get a racing bucket that works with the OEM belts if you still don't feel like you're held in place. After that it's time for monkey barz. What Richard said is absolutely true. You can probably go with a lot of the compromised solutions out there for getting a harness in the car, and you might be ok even in a crash, but it's not that much harder to go all the way and do it right. In the end only you can decide what balance of risk and hassle you're willing to deal with.

There are plenty of people who won't agree with what I have to say, so take some of what I'm about to say with a grain of salt, but I've crashed enough and seen enough bad outcomes to know you don't screw around with this stuff.

You can go one of two ways, either use the OEM safety systems with some slight enhancements, or go all the way with racing-style safety gear. In my opinion, there is very little in-between here, both approaches are designed to work as a system and you can't pick one part here and one there and expect a good outcome, even though many have lived to tell about it. Safety gear used improperly is sometimes more dangerous than none at all.

I think it's safe to say that mounting a lap belt to the seat mounting bracket is a bad idea, though I'm sure many have lived through it just fine.

The sub strap is for travel limiting, it is not designed or intended to do anything more than hold you in the correct orientation so the lap and shoulder straps can do their jobs. The lap belt and shoulder harnesses do the majority of the work in a crash. A less robust mounting for the sub straps, or even piggybacking on the lap belt mount, is usually fine.Even the sub strap should still be anchored separately from the seat though. The seat moves a lot more than you'd expect in a crash and you want the belts to be independent from the seat so that you don't lose tension when the seat moves.

Those b-pillar bars should really only be used to keep the harnesses in the right place for low-speed stuff like autocross, in my opinion there is too great a span and everything I've seen bolts in and is made of 1" tubing or smaller, which isn't crashworthy at all. The loads on a shoulder harness in a 10+g crash are huge.

If the goal is safety, you have to think about what's going to happen when you're taking the car off a sweet jump and doing a backflip, not just what works to get the thing in the car and mounted. Once you go start thinking along those lines, logic dictates you need to do at least a half cage and a racing bucket to provide roll support and a solid foundation for the harnesses to work from.
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      02-06-2012, 10:32 AM   #10
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Quote:
Originally Posted by Richbot View Post
...logic dictates you need to do at least a half cage and a racing bucket to provide roll support and a solid foundation for the harnesses to work from.
Thanks for so much info. I suspect you're right. I'm probably hoping for too much in making the E90 a do-everything car. Ideally, I'd have a dedicated track car and this would all be a non-issue. But we only have a 2-car garage and I doubt the neighbors would like looking at a trailer and racecar sitting in our driveway.

I could theoretically look for a used GT3 to be a better daily-driver/track car compromise in terms of having a half-cage already in place, but then I would have no ability to use the car for getting the kids around, and winters would be impossible.

I feel like I've already invested enough in my car (StopTech brakes, suspension upgrade, dedicated track wheels) that I'd hate to abandon it and head in a different direction this early. But as you point out, safety is the main consideration.

I have the CG-lock and it helps somewhat, but I still find myself sliding a bit in the seat--a couple of times per lap I'm wiggling around to recenter myself. So maybe just doing a dedicated race seat like a Recaro or Racetech in conjunction with the CG-lock and stock belts would be the answer? At least for now it would hopefully keep me more planted in the seat. I assume I would need to undo the stock belt's floor mount and thread the belt through the side belt guide on the new seat, then reattach it to the floor mount.
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      02-06-2012, 11:34 AM   #11
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I think a racing bucket is a good compromise for your situation, but I don't think you'll die in a fiery crash immediately if you get a harness either. I was just being pedantic.
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      02-06-2012, 12:24 PM   #12
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Quote:
Originally Posted by Martin_D View Post
I have seen harness bars by AE Performance and FMU (Fluid Motor Union). I used the AE bar in my E90 (sorry, no photos).

EAS or VAC make sub harness mounting plates...

EAS also makes all of the Macht Schnell pieces to bolt the seat into the E90 with ease. Make sure to get the occupancy deleter from there to remove the airbag light.
Appreciate the referral, here's a set of Macht Schnell mounts for those with Clip-in type harnesses:



Floormounts:


Sub belts can clip to a Sub bracket:



There is a solution for bolt-in harnesses also, hope this helps!
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      02-06-2012, 01:59 PM   #13
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Quote:
Originally Posted by LiM3y View Post
Do you have zoomed out photos...I am not sure what I am looking at there!
Top to bottom: left lap strap (left side of seat), right lap strap, and anti submarine straps (under seat).

Richbot has summarised various considerations of harness/roll bar installation extremely well.
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      02-06-2012, 03:43 PM   #14
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For the E46, the schroth quick fits is what makes the E36 and E46 platform, IMO, the best track car/DD for even advanced drivers.

I think quite a few of us want the E9X to have this same flexibility. Which has proved to be quite possible with the exception of (the ones I am aware of) potential P/S and heat issues and harnesses or something that holds you in the seat. Especially among the E90 owners. Putting a harness bar in the back is a non-starter for, IMO, a lot of us.
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      02-06-2012, 04:08 PM   #15
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If staying strapped in tightly in race condition is the goal, and don't want to go all out with roll cage & harness bar, Recaro, etc, then try sliding your OE seat back and tilt the back rest down, quickly jerk and lock the seat belt into the recepticle, tension the seat belt to keep it locked, then slide the seat forward and bring the back rest up again.

Doing so now gets me strapped in real nice & tight, and no longer slide around on the seat at the tracks. I don't even get the side of my knees bruised any more.

Oh, and, CG lock doesn't work.
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