I want to replace the OEM plastic water pump impellers with aftermarket impellers. Here's a description from Bimmerworld.com

OEM replacement parts, includes gasket. We replace M50-engine pumps that originally came with plastic impellers with aftermarket parts with metal impellers. The original pump is a failure item - our metal versions are much higher quality.

Same thing for the OEM plastic thermostat housing

For M50 based engines - common failure part! This part fits all US M50 based engines (92-99 3 Series, 5 Series, and Z3 with 6 cylinder engine, including M models). The is part replaces the stock plastic thermostat housing with this updated aluminum part. Replace it before it breaks - it will eventually. Gasket included.

These two items are clearly maintenance items that I want to upgrade to prevent failure. I see no advantage that I would get. So my question is...if I don't see it in the 2005 rules, does that mean it's not allowed? Or is it?

Thanks,
Gio

These two items are clearly maintenance items that I want to upgrade to prevent failure. I see no advantage that I would get. So my question is...if I don't see it in the 2005 rules, does that mean it's not allowed? Or is it?

Gio, I don't know the SPU rules and IIRC they may differ from region to region. You may need to contact your local region tech stew for a ruling.

SCCA rules are generally written so that if it doesn't say you can, you can't. Keep that in mind when reading the rules. Also, gaining an advantage or not is not the point unfortunately.

I think the aluminum thermostat housing is definitely a no-no. But, you can replace the old one with a new plastic part from the dealer. OTOH, I don't think these fail nearly as often as the plastic radiator necks or the old plastic water pumps.

On the water pump front...you probably don't want a metal-impellered pump that is OEM. You probably want the OE composite impellered pump that is sold by your BMW dealer and also understeer.com. You can search on the forum for threads concerning the differences between the two.

I'm not an SCCA rule expert, but I would think that if you go to the dealer and tell them you need a new water pump, whatever they give you would be SCCA stock class legal (and thus ST legal). I'm sure someone will correct me if I'm wrong.

Kent

Sounds like my suspicions were confirmed. If it's not in there then it's not allowed. Yet these items give me NO advantage whatsoever. But again these are the rules.

But it does now save me money on parts and labor. Now about the gauges that some M3 owners put in under the OBDII display? I want to get the ECIS gauges. Would this fall under cosmetic enhancements to the interior (i.e. pedal sets, shift knobs)?

Thanks,
Gio

Sounds like my suspicions were confirmed. If it's not in there then it's not allowed. Yet these items give me NO advantage whatsoever. But again these are the rules.

But it does now save me money on parts and labor. Now about the gauges that some M3 owners put in under the OBDII display? I want to get the ECIS gauges. Would this fall under cosmetic enhancements to the interior (i.e. pedal sets, shift knobs)?

Thanks,
Gio
The gauges are legal.

Oops. Sorry, I confused STU (autocross) with SPU (club racing). Disregard all of my comments. I know diddly about autocross rules.

Oops. Sorry, I confused STU (autocross) with SPU (club racing). Disregard all of my comments. I know diddly about autocross rules.

You know I figured you made a typo! But didn't know there is an SPU class but in club racing. My mechanic races in the SoPacDivision in ITS class and he's winning his class locally. John Norris in a BMW 325.

Thanks,
Gio

The gauges are legal.

Thanks SoloII

Gio

Unless BMW has put out a service bulletin stating that a different water pump should be used in your car, or it was used in some of the same model cars built in your year, changing the water pump would be TECHNICALLY illegal, as would the aluminum housing. However, if you were protested you could claim that it was a non-performance enhancing modification and I'd guess you would have a good chance of winning.

More importantly, this likely falls under the category of 'things you really shouldn't worry about'. Mostly because I can't ever see anyone protesting you for this (or even caring about it), unless you perhaps won nationals. Most of your fellow racers understand that you can't always get a part that is 100% EXACTLY the same as the one which came from the factory, and that sometimes reliability has to come before legality in our cars. Since many autocross cars are also daily drivers, people tend to be a little more understanding if you car is only mostly legal.

So, in my opinion: Could you get protested? Yes. Should this stop you from installing the water pump and t-stat housing? Nope.

-Bret

I have to agree...The Ronak part is a replacement thermostat housing, and actually weighs more while providing no performance advantage. If someone were to protest you, take them out back and beat them with a rubber hose...

As for guages....if you want the most comprehensive kit on the market...click on my sig!

Could the thermostat housing be replaced indepedent that of the thermostat
itself? Under the stock rules, thermostat may be added or substituted.

Could the thermostat housing be replaced indepedent that of the thermostat
itself? Under the stock rules, thermostat may be added or substituted.

The thermostat housing and thermostat are independent.

Chris

I have to agree...The Ronak part is a replacement thermostat housing, and actually weighs more while providing no performance advantage. !

:confused It's not a performance enhancement? If your front tires are running on dry pavement and your rears are running on your own coolant I don't think it will be a good run. Name one person that can drive the same times on a wet course as a dry course.

The plastic housing is no different from a 911 chain tensioner or a Elan drive donut.

Just replace it. If you go to a parts place and ask for a Thermostat housing, that's what they will give you. It kinda falls under the replacement part sections of the Stock Class Preamble.

I don't think anyone would actually protest based on that. If they do, state that the stock ones fail, which could cause you to spill coolant on the course, causing an unsafe situation for yourself as well as a delay to the event.

And if someone does protest based on that, I'm guessing the Protest committee would not uphold the protest and there would be a clarification made in the rules.

:confused It's not a performance enhancement? If your front tires are running on dry pavement and your rears are running on your own coolant I don't think it will be a good run. Name one person that can drive the same times on a wet course as a dry course.

The plastic housing is no different from a 911 chain tensioner or a Elan drive donut.
This may be the dumbest response I have seen in a while.....Is it providing an advantage for the car? No...just preventing it from puking coolant all over the course WE ALL HAVE TO RUN ON...Jesus, are you kidding me?

This may be the dumbest response I have seen in a while.....Is it providing an advantage for the car? No

YES, it is an advantage being able to complete all your runs. If people didn't think it was an advantage they wouldn't want to change the housing.

Just replace it. If you go to a parts place and ask for a Thermostat housing, that's what they will give you. It kinda falls under the replacement part sections of the Stock Class Preamble.

I don't think anyone would actually protest based on that. If they do, state that the stock ones fail, which could cause you to spill coolant on the course, causing an unsafe situation for yourself as well as a delay to the event.

And if someone does protest based on that, I'm guessing the Protest committee would not uphold the protest and there would be a clarification made in the rules.


Hey Matt what's up? This is Gio (Cal Club and BMWCCA-SD). Great course design for the SD Chapte. Anyway I do want to replace it but want to follow the rules also. I think perhaps this a situation where a letter to Solo Executive Board explaining my case, would cause them to re-write the rule perhaps. Any opinions?

Gio

YES, it is an advantage being able to complete all your runs. If people didn't think it was an advantage they wouldn't want to change the housing.


Here's the thing...we dont carry and wont install a plastic housing...you know why? Because they fail...They don't flow better, they don't cool better, but they don't break either... Its a maintenence advantage...If you are at Nationals and the guy in front of you pukes coolant because his plastic neck fails, you'll be singing a different song.

STU guys, write the letter and I'll sign it, I see them fail all the time. I am in favor of "OEM Replacement Parts that offer no performance advantage"

:confused It's not a performance enhancement? If your front tires are running on dry pavement and your rears are running on your own coolant I don't think it will be a good run. Name one person that can drive the same times on a wet course as a dry course.

The plastic housing is no different from a 911 chain tensioner or a Elan drive donut.That's ridiculous! If someone were to protest that then they are just a sore LOSER!!!

Paint aluminum thermostat housing flat black.

No one besides a BMW freak would even think to check it out, and if its black it will look like the plastic unit at glance.

And others are right, no one will protest unless you win nationals. The Solo2 community is generally very nice about things like this.

But, bottom line is that it is illegal in STU.

I had to put the fan back on today to be legal for STU, so while I was there, I went ahead and put in a new OE plastic housing. I'll keep the aluminum one for when the rules change. From what I here, the plastic one can go 60K or a few years, and it's not a huge deal to change it anyway.

I also pulled out the tranny rings. So I am almost STU ready now.

Chris

Look at it from the View point of the protest Commitee. Were you doing it for a competetive advantage, Or were you doing it to save course workers time so they don't have to clean your engine parts up off the course?

I don't think any Protest Commitee in their right mind would boot you or penalize you for putting on a better quality water pump.

YES, it is an advantage being able to complete all your runs. If people didn't think it was an advantage they wouldn't want to change the housing.

It's an advantage for my bank account and other drivers. Not for my times, which is the bottom line of all this. The reason these rules are around are to keep things safe and fair for ALL participants. Replacing your housing with an OEM equivalent is done for the advantage of EVERYONE at the event, thus no parity is broken. If you think someone is going to protest and you're not willing to give up a Nationals trophy, then stick with the plastic. If you're willing to trust the good nature of Solo drivers who rational are 99% of the time, I say go for it. Personally, I would replace it. Safety's #1. Reliability's #2. Speed's #3.

Pretty heated for being 3 years old:)
Good to see it brought back, I bet a few people (me included) didn't know about the tstat housing.

Even at national's someone wouldn't protest you. And if some complete ass did, i guarentee it wouldn't even make it to the protest committee. And in some chance in hell that it did, they wouldn't disqualify you.

If you're concerned about it just shoot an email to the SEB.