Just got new SE30 to race - boatload of questions

#1

I need a little help from some of you with SE30 experience.

I am now in possession of a 90% complete 1987 BMW 325 IS which I will race in legal SE30 trim. The car will mainly run in Florida and the Southeast, although I may also take it to Nationals, so the car needs to be 100% legal. I really dig this car. This car will never, ever be driven on the street. I have pulled and read the rules several times and have searched the forums to try to answer the following questions, in no particular order:

This car appears to have factory ABS. First, is it any good, second, can it be removed if I want to? The rules do not say anything about ABS.

Can I install an adjustable brake bias lever in the car? My reading of the rules indicates the answer is no.

The car has the spec springs in the car already installed. On the rear, the middle coils of the springs look like they are already binding, and I haven’t even driven the car off-road, hard, at speed yet, which I will do. Is this how they are supposed to look? Also, the part number on the spring in my car is H&R Z/A RG701 HA.10. That is nowhere near the spring listed in the rules (part number 50404-88). Does this cross reference somehow or do I have the wrong spring in the car?

Oil pans: first, the stock pan looks to be the lowest point of the car, which means when I run over a curb, it goes first. Is that accurate? If so, what is the cure for this? Second, do people run aftermarket pans, or is the stock pan good enough? I do not want to install an accusump on the car.

Master kill switch. I would like to have one in the car, and the rules require one on the outside. Does anyone have a dual switch on their car, and if so, what is the routing.

Where is the best source to get tow hooks (straps, actually). I envision running something like the spec miata bump draft tow straps. Where do I bolt them to?

Wiring, wiring, wiring. Here is where most of my questions are. My reading of the rules did not find much mention of whether you can remove wiring of components that do not remain. For example, the car has no windows and no locks anymore, but the car still has the power window and door control switches just laying in the bottom of the door. There is a rash of assorted wires spewing from under the driver’s side of the dashboard. It is likely that I will pull the dashboard out, remove the heater core box and AC components, remove all of the factory gauges, rip out all the wires, and just rewire back what I need. Is this legal? Same question for other wires that used to sit in the center console, there are various switches that are just laying around the transmission tunnel, and a bunch of other wires that just seem to have no obvious purpose. I hate wires without obvious purpose, they strike me as being unsafe. I am not removing them for a weight purpose, I want the car clean, easy to maintain, and safe. I will make sure the car weighs in legal.

The car has screw in studs, but the stud has a long shoulder on it, and the lug nuts may not be getting tight enough before the nut bottoms out on the shoulder. Where can I get the thinnest spacer available? Yes, I read the track width rule and I will make sure the car is compliant.

Is the battery unrestricted? The rules just say the battery can be changed. Can I add a lightweight battery if I want? In truth, the car is going to weigh in light anyhow, so I suppose a big heavy battery in the stock (passenger side trunk) location is probably what this car wants anyhow, but thought I would ask.

The prior owner had taken the cooling system somewhat apart. I am going to run without a thermostat. The thermostat housing is one of the most bizarre I have ever seen, and to add to the fun, the car came without hoses and with the thermostat housing off the car so I have no idea what the routing was. It appears that there are three large bibs off of the housing where a radiator hose could go. What do I do with this? Seems to me that the radiator hose can only go to one of the three, unless there was some kind of bizarre distribution system.

This car has no third brake light. Where can I get one to install? The rules seem to require it, although I do not believe this car was so equipped, or at least someone before me took it out.

I am sure I will have more questions as I progress, but help with any or all of the above would be greatly appreciated.

-Scott McKay

#2

Re. ABS. As a general rule, if the CCR doesn’t mention it, then you can’t mess with it. You can’t mess with ABS.

Re. Adj brake bias. No.

Re. Springs binding. The rear springs do bind some. I don’t know about the part #.

Re. oil pan. An aftermarket pan has just become avail and just become legal. Paul Poore makes it. A search will find his phone #. Factory3Performance sells an oil pan shield which is pretty much a must do. If it doesn’t already have a crankscraper, I’d put one in.

Re. tow straps. Most folks loop a strap around a bumper shock. There avail in several places. TurnerMotorsports is one.

Re. kill switches, some folks do have 2. Routing varies.

Re. Wiring. I’m not sure if the rules explicitly state that wiring can be removed, but I’d go ahead and remove any wiring you want. Much of the stuff the wiring goes to is explicitly allowed to be removed, and if you can remove I think that it’s fair to assume that 's wiring could go to.

Re. studs. As I recall you want at least 6 turns of threads on a lug nut. Vorshlag makes 5mm spacers, but if you can’t get 6 turns, then longer studs might be a better idea. Cheaper too.

Re. battery. Unrestricted.

Re. thermostat. You need it. There’s a long thread around here where I drove everyone crazy about cooling. One of the things that came out of that thread is that if you have no thermostat then the hot water from the head can go right back into the block without going thru the radiator. That thread also has a diagram of hose routing. And RealOEM.com is your friend.

Re. 3rd brake light. Since the rules don’t say you can remove it, you can’t. Therefore you need to find one. It’s probably not a crisis, as long as your other brake lights work.

In general terms, folks are pretty darn reasonable. If you’ve a new car and you suck, folks are going to fall all over themselves trying to help you. They will understand that it takes some time to dot every i. But the less you suck, the less tolerant folks are going to be of CCR violations.

Welcome aboard Scott. You’re going to have a great time. Where in FL do you live anyhow? There’s two of us in Savannah.

#3

Thanks, Ranger. I live in Bradenton, an hour south of Tampa.

I was unclear on the stud question. I get plenty of turns on the lugnuts. Too many actually. The lugnut bottoms out on the shoulder of the stud before it fully clamps on the rim. That is why I need a small spacer, assuming it does not make my track width illegal.

Regarding a crankscraper, where do you get that, and does the pan come right down straight, or do you have to wrestle it around something. I haven’t looked that far under it yet.

Another question, the Paul Poore exhaust I have does not appear to have a bung for the Oxygen sensor. Am I nuts?

Under all circumstances, thermostats are the enemy. I will research your post and find another way. I hate them. I also plan to run with no radiator fan of any sort.

The rack in this car does not have any fittings coming out of it. With no fittings, I can’t put a piece of hose between said non-existent fittings to keep the rack oil from coming out. Anyone know what the thread is that is suppose to be there, so I can go and get some?

My experience with the rules is that I seem to get very little leeway, therefore I want to do everything I can to bring a car that is 100% ready to go. I can’t wait to get this thing running, and will keep you updated.

-Scott

#4

Can you put a bias valve in the system anywhere except the cabin, or no bias valves?

#5

BigKeyserSoze wrote:

You are allowed to put a bias valve in your tow vehicle.

O2 sensor goes into the downtube, which is before the Poore exhaust.

Scraper comes from Factory3Performance. If you get the more expensive teflon version you won’t have to do so many test fits.

The pan is a pita to get out. There’s 2 ways to do it:

  1. Unfasten the front subframe and steering box and drop the pan. I’ve not done this.

  2. Unfasten the engine and tranny mounts and lift the engine a couple inches. Then remove the 400 oil pan bolts and drop the pan those couple inches. Then reach inside and unfasten the oil pump and return checkvalve and allow both to drop into the pan. Then wiggle pan out. This I’ve done. Not too hard.

Putting in the crankscraper is not easy tho. It takes some grinding to make it fit and each test fit is a pita. Then you have to get some high adhesive gasket material and slap it around the bottom of the motor. It will drip into your eyes, face, shirt and hair.

Spray a little brake cleaner into the block’s oil pump holes. This is prep for the locktite later.

Put in the crankscraper and put in some bolts to hold it in place while the gasket goobage dries a bit such that it will hold the crankscraper in place reasonably securely. Then put oil pump and checkvalve into the oil pan. Then wiggle the oil pan into place. Reach into the oil pan from underneath and put the oil pump in place. Use locktite on the bolts and return checkvalve and fasten everything in place.

Fasten the 400 oil pan bolts into place and drop the motor back down.

Putting in a scraper with the motor out takes about 15min. Doing it with the motor in place takes a while. Come up with an excuse to pull your motor and you’ll have the scraper installed in a jiffy.

Re. steering box. Someone around here sells threaded plugs that go right into the rack. That’s the best solution because otherwise the looped PS hose just gets in the way of the motor mount every time you R/R the motor. Which is less of an irritant, admittadly, to those that don’t have to pull their motor every other month.

#6

go with option #2 that ranger suggests for dropping the pan. i’m getting the paul poore pan. best way is to give paul a call (215) 766-2555. i won’t be using a scraper with his pan but ymmv. you can remove wiring you don’t need. stick with the stock battery, you need some weight in the rear. bimmerworld sells the tow straps and kill switches as well as the longer studs you need.

#7

kishg wrote:

+1 for BW. They are very supportive of the series.

#8

Ok Ranger, I read your entire thread on the cooling system and digested it all. Here is what I think works to cool the engine and be rid of the thermostat:

First, I think you were onto something with routing the water that is in the back of the head back to a y neck between the thermostat housing and the radiator inlet. I am going to do just that, put a y fitting in line between the thermostat housing and the radiator inlet, and plumb a line from where the head would otherwise connect to the heater (fitting 11 on the diagram you found) back to this y fitting. Then, I am going to take the hose from the radiator outlet, and instead of running it back to the thermostat housing, I am going to run it directly to the water pump inlet. I will cap off the thermosat housing bib where the radiator outlet used to connect to it, and I will also cap off the thermostat housing bib that used to feed the water pump. Finally, I will disconnect the heater return line (fitting 12 on the diagram you found) and cap off where it would otherwise have returned to the thermostat housing. I will leave the hose from the back of the block to the throttle body, and the throttle body to the thermostat housing alone, assuming that the throttle body still has exhaust gas running through the spacer as part of the EGR, can you confirm? If so, the coolant should cool the spacer, but even that is an unknown. Back in my days with Mustangs, I am told that there was so little exhaust gas running there, that the coolant actually heated the throttle body. If that is happening, these coolant lines should be disabled, too.

I will check the downtube and see why the oxygen sensor was not put back in.

If you think of who sells the rack plugs, let me know, as I need those.

I am not going to play with the oil pan for now. I have enough stuff to break, including figuring out all the wiring. Where would I go to get a total wiring diagram for this car, one that actually works and properly identifies colors, not the Haynes manuals, which I have had bad luck with.

-Scott

#9

The consensus on the throttle body hose is to block it off. Normally folks block off something by using a couple inches of hose and then sticking something in the hose that stops it up. But that defeated me at RA in Dec when my 5" of throttle body hose burst. The aftermath of that is the horrendous 29page motor rebuild thread. That, sadly, is going to get bigger yet.

I have the throttle body hose plugged at the tstat by a bolt. It’s plugged at the block by my coolant pressure sensor hose. The heater hose at the back of the head is blocked by an aluminum plate. The heater hose at the tstat is blocked by a rubber stopper sort of thing that expands when you turn it’s screw.

I’m torn on piping coolant from the outlet at the rear of the head. Allowing water out of there has the potential of messing with the coolant flow rates at other points in the head. As you know the size of the holes in the headgasket control flow rate by attempting to create a standardized coolant pressure differential between the block’s water jacket and the head’s water jacket. I figure that the BMW engineers calculated that carefully so I’m hesitant to screw wit hit.

I’ll have to sit down with a diagram and figure out what you are describing with the thermostat bypass. Sure, there’s a preferred temp range for motors, but it’s hard to say exactly what it is. I’ve heard mention of running cold thermostats to make the engine run colder, but I’m not sure I understand how that’s supposed to work. Just because the thermostat opens a little earlier shouldn’t affect the steady-state temp of the motor. The only way to impact the steady state temp is to create less heat, or dump more heat. Anything else is transient.

I would assume that a colder motor would mean a denser air charge, but I’m pulling that out of my butt.

#10

Regarding hose plugging, I usually just use a fresh piece of properly sized hose with a bolt pushed in tight and hose clamped. I have also used vaccumn caps which work well. For larger bibs, the parts stores actually have nice rubber caps that you hose clamp on.

At the thermostat I will plug the throttle body hose with a vaccumn cap, same with the fitting on the block. The heater hose at the thermostate you should block with the rubber cap that I discuss and not what you discuss. The rubber caps never let you down.

I will consider your thought about the flow rate. Truth be told, the engineers know this one best, and I’m not one of them. My real question is whether, from the factory, when the heater is off, if there really is a blocker valve that prevents water from circulating through the heater box. If there is a blocker valve, I’d have to side with the engineers. If there is no blocker valve, I’d do it my way.

I throw preferred temperature out with a race car. The car is going to run hot, and I don’t want the thermostat restricting flow, sticking, etc. I want that water moving around when I start the car. Just less to think about. I may go without a water temp gauge, instead choosing to use a low pressure switch. As long as the cooling system has pressure, it should do its job. I’ve never overheated a car yet when the system retained its pressure. Only once you have a leak and lose pressure do things overheat.

I’m not trying to lower the end temperature by eliminating the thermostat, because that is a pipe dream. In a race of any substance, it is going to get as hot as it is going to get. I just want to eliminate one more thing to fail, and in the process, eliminate some rubber hoses that also like to fail.

I do not think a colder motor means a more dense air charge. Air density is determined by the temperature of the atmospheric air, the pressure of it, and the humidity. The air flows through the intake so fast I do not think there is any appreciable heat change, but then again, I’m pulling that out of my butt.

-Scott

#11

Hi Scott,
kill switch needs to be accessible from somebody on the outside - the switch does not need to be on the outside. It could be just inside a window, or a pull cable could go to an outside handle.

wiring that is associated with something that is allowed to be removed, can be removed.

the rules don’t say you can do all those plumbing mods you suggest. Keep things simple.

here is one option for plugging the rack http://www.e30tech.com/forum/showthread.php?t=72123&highlight=steering+rack+delete

thanks,
bruce

#12

BigKeyserSoze wrote:

[quote] The rubber caps never let you down.
[/quote]

Can you send me a link so I can see what you mean?

Leggwork’s right about the rules and plumbing mods. The rules allow the heater bypass and the stat seems pretty much free. But using the hose to bypass the entire tstat housing isn’t really the same thing as modifying, removing or replacing the tstat itself.

That being said, if you figure out a good inexpensive mod, submit it to Natalie as a request for rules change. In my experience she’s a hard-ass tho.

lol.

<I couldn’t keep a straight face on that one>

#13

yup, that aluminum spacer that bruce suggested is exactly what i’m using:

http://www.e30tech.com/forum/showthread.php?t=72123

#14

oops, just remembered that that ps delete block needs you to have your stock banjo bolts which I don’t think you have. I know I’ve read a thread with the size and thread pitch of those bolts so you can get non-banjo versions at a hardware store.
bruce

#15

When the heater is off the valves block the flow of coolant through the heater core.
Don’t loop the heater hoses, just block them. If you loop the heater hoses part of the coolant flow will bypass the radiator.

With respect to the thermostat, the hotter an engine runs the better its efficiency and thus its power. The thermostat is a compromise between the desire for a higher engine temperature and material service limits. And there’s the issue of the maps built into the DME which are temperature dependent. Those maps are designed for efficient operation at normal engine temp (170-180F). Unless there are other problems, an M20B25 engine won’t run hot with a thermostat. Leave it in.

As to window wiring, though not explicitly called out in the rules a system that can be legally removed can also have its wiring removed. So if the windows are gone you can remove their wiring. Likewise for the audio, OBC, door locks, and HVAC. Te rest or the car’s wiring has to stay in place.

#16

jlevie wrote:

[quote]
Those maps are designed for efficient operation at normal engine temp (170-180F). [/quote]

Your motor normally run <180deg?

#17

If running in the SE you had better get your liver in shape.

Re. Alonzo Graham Taylor III

ps, you left a dent in the truck lid of my biodiesel

#18

Ranger wrote:

So far, the highest I’ve seen on track has been around 190F. That agrees fairly well with what the stock temp gage indicated when I still had the stock cluster in the car. The highest I saw on the stock gage was the needle being just barely above the 12 o’clock position, which would be 190-200F.

#19

Anyone have a thought on my rear spring part number question?

#20

And Al, there were so many dents in that raggy biodiesel of yours, you can’t dare try to lay that dent in the trunk lid off on me.