We broke a timing belt at Road America, so my 1990 GSX is sitting on jack stands, with the head in Indiana getting worked on, and the rest of the engine on a stand waiting to be disassembled. Therefore, I got lots of time to think about what to do with the car this winter. Here are a few crazy ideas and questions:

1. Blowing a timing belt is a real expensive bummer. (It blew because the turbo heat melted the plastic timing belt cover, and the cover got into the belt). I am wondering if we should install a switch of some kind in the new belt cover that would go off when the timing belt starts to unravel (my timing belt definitely unraveled, big time). The switch would be wired to a big red light on the dash that says "Shut off the motor, dummy! NOW!" I assume that I would get a few seconds warning when the belt starts coming apart, and would have time to take action. What kind of switch, do you think? An on/off toggle switch that would get whacked by pieces of belt? A proximity switch that would detect pieces of the belt getting close? Ideas?

2. I plan to install a front splitter like Greg Collier's to (a) get front downforce (b) channel air up to the rad from underneath and (c) form brake ducts for cooling the rotors. The car seems perfectly balanced now, so I wonder what increased front downforce will do to the balance. Maybe I need a better rear wing. Problem is, I have a 1G (see photo), and can't figure out any way to put a wing back there without "ricing up" the car. Has anyone seen a decent rear wing for a 1G?

3. Along the same lines, I plan to cut a hole in the hood to allow heat to escape from the area surrounding the turbo. I saw a DSM at Road America with a nice slot cut in the hood, and a lip in front. The owner says he did some testing with a heat sensor, and the little lip apparently helps scavenge out the heat. Maybe it's a venturi effect? Any thoughts on this, or how to get heat out of the engine area?

4. As I said, the head is off to a shop in Indiana, and I am waiting to hear the verdict, costs and options. As near as we can tell, it has already been ported and polished, and the valves look OK after 10,000 miles (well, except for being bent all to hell). Any ideas on what I might do to improve the valve setup? Remember, it's road racing, not drag racing.

5. Except for being whanged, the pistons look good, too. They are 95 pistons. With only 10,000 miles on the motor, I suspect the crank, rods and bearings are probably OK. I'd like to run 20 OR 29 psi at the track (switch selectable). Any recommendations on what to replace the pistons (or anything else) with? Or should I stick with 95 pistons?

6. I can't find an upgrade kit for the rear brakes. Does one exist? I'm running StopTechs up front.

7. I had a problem blowing oil filters this summer. With advice from folks on this list, Mike the Mechanic (my wrench) took a Dremel to the oil filter housing relief valve port and reduced the oil pressure from 120 psi down to 105 psi. We didn't blow another filter, but the oil pressure still seems a bit high. How do we drop it another 20 psi or so? The motor is (or will be) completely disassembled, so we can do just about anything at this point. But what?

All ideas are welcome.

Rich

#1. Maybe mount something to the front cover down where the balance shaft belt used to go. That's about the best thing I can think of right now.

#2. The most affective wings are rarely the most attractive, this is an excercise in personal restraint here between the most badass downforce making wing in existence and keeping the car looking good. I'd do the splitter first and see how the car responds. If nothing else look into moving any possible weight such as the battery to the back of the car to help. Slightly softer rear swaybar or springs may help if it begins to oversteer like a late 80's porsche

#3. This is one of those areas where I love to look at current racecars. If they're using it then you can rest assured it works, noones putting non-functional vents onto their LMP cars. Personally I'll be looking to do a carbon fiber hood for reduced weight and using a hood vent from Carbontrix which is what Greg runs on his car.

#4. I'd go with the 1mm over valves as the labor to instal them isn't that much more than rebuilding the head with normal valves. You may look into having the head ported, what shop is it that you sent it to? Almost anywhere can rebuild a head, but you don't want just anybody porting the head.

#5. Well you could run 1g pistons since they're lower compression and would allow you to get away with more boost on pump gas, as compared to 2g pistons. Are you detonating now at your current boost levels?

#6. Check out TCE, they sell upgraded rear brake kits, but I believe you lose the ability to use the parking brake as the larger rotors push the calipers past their maximum adjustment levels. I'm sure with some engineering the emergency brakes may be retained.

#7. Did he try cutting a coil off of the relief valve spring? It's risky business and a pain in the butt since you have to dissasemble the car's timing belt side to get to it I believe. Not dones this myself personally however, but I've seen a few threads about it.

My views...

Slow old poop said:

1. Blowing a timing belt is a real expensive bummer.

The big red light is a good concept but in race conditions I don't know if your reaction time would be fast enough to shut down the motor at 29PSI at 8K RPM..

2. I can't figure out any way to put a wing back there without "ricing up" the car.

Your driving a rice born car, who cares what the guys are saying. When your fuel load is down to nothing and you're power drifting at 150 MPH you'll be glad there's something back there keeping your ass on the ground.

3. I plan to cut a hole in the hood to allow heat to escape from the area surrounding the turbo.

Using the Carbontrix vent gives a little more areo to the hood.

4. As I said, the head is off to a shop in Indiana,

IF, we run next year... we're going for a consistant 400WHP with the baddest stroker motor ever built. I hear the cars running in my class next year are suppose to be insane

6. I can't find an upgrade kit for the rear brakes. Does one exist? I'm running StopTechs up front.

I use to ask this very same question until I actualized I'd probably be setting the ballast to OEM specs.


Rich

Click to expand...

>The big red light is a good concept but in race conditions I don't know if your reaction time would be fast enough to shut down the motor at 29PSI at 8K RPM..

I was hoping I'd get a little bit of warning when the belt started to unravel.

>Your driving a rice born car, who cares what the guys are saying. When your fuel load is down to nothing and you're power drifting at 150 MPH you'll be glad there's something back there keeping your ass on the ground.

Yes, but it would be nice if looked good, too.

>IF, we run next year... we're going for a consistant 400WHP with the baddest stroker motor ever built. I hear the cars running in my class next year are suppose to be insane

IF? What's this IF stuff? Got something to tell us? You are our road racing hero, you know. You can't quit now. The rest of us are just getting started with DSMs and we need your advice and experience.

What's all this about a stroker motor? My engine is apart right now, so I could go that way too. What's involved? (Mike the Mechanic, are you listening?)

>6. I can't find an upgrade kit for the rear brakes. Does one exist? I'm running StopTechs up front.
I use to ask this very same question until I actualized I'd probably be setting the ballast to OEM specs.

Well, you got me on this one. I have no idea what you just said. Was that a yes or a no? What ballast? Explain, please.

By the bye, unless I missed it, you never gave us a report on the final race of the season. Please start a new thread and tell us all about it. I'm sure I speak for the rest of the road racers here when I say we are all with child in anticipation.

Rich

Ballast!!! Ballast! See what happens to me after a couple of glasses of cheap red wine WTF

I meant "Brake Bias" using a proportioning valve to achieve a dynamic bias between the front and rear brakes. But you and I are driving different animals you being AWD. You have the weight in the rear with your drive train setup and you're still running the stock gas tank under the rear seat. I, on the otherhand have an axle, coilovers, and a fuel cell. Plus my rear window is polycarbonate that drops another 50 lbs or so from my butt. Just about all of my braking power is in my front end, and that's how I've learned to drive my car, which by the way, is my, and continues to be my biggest challenge.

As far as the "stoker" motor goes, there's so much information on this site about this application you can't miss it. I know I'd probably have to increase the size of my radiator among other things to keep it driveable at balls out speeds for long periods of time.

The big "IF" I run next season, is what I say every year at this time. It seems to get more expensive to race a series every new season. At this point I don't have finite sponsorship pledges for 2006. There's been a lot of talk and part of that talk is, "We'll see if you win another championship." No body remembers, or for that matter cares about who came in second place. You've also gotta keep in mind that I've been putting balls out energy into my race program for four years straight now

As far as my last commentary, if you'd give me the chance to actually RACE my last race I'll be more then happy to write it up. We're running Buttonwillow Race Park near Bakersfield California on November 12-13 in two weeks

Slow old poop said:

I was hoping I'd get a little bit of warning when the belt started to unravel.

Click to expand...

Unless you get EXTREMELY lucky, you won't have enough time before the destruction already has happened. The timing belts, for all their strength, disintegrate once belt integrity is comprimised. If the belt doesn't snap completely, usually the teeth with strip off the backing and once that happens, it doesn't matter of the backing is intact, your values are already bent.

Spend more time and money working on decent air flow not just for the radiator but across the tranny and timing belt sides as well. Help it do what it is supposed to do.

Slow old poop said:

IF? What's this IF stuff? Got something to tell us? You are our road racing hero, you know. You can't quit now. The rest of us are just getting started with DSMs and we need your advice and experience.

What's all this about a stroker motor? My engine is apart right now, so I could go that way too. What's involved? (Mike the Mechanic, are you listening?)

Click to expand...

No kidding. If you need someone to come turn a wrench, build an engine, tweak a suspension, just fly me out.

Slow old poop said:

>6. I can't find an upgrade kit for the rear brakes. Does one exist? I'm running StopTechs up front.
I use to ask this very same question until I actualized I'd probably be setting the ballast to OEM specs.

Well, you got me on this one. I have no idea what you just said. Was that a yes or a no? What ballast? Explain, please.

Click to expand...

A full bias spec upgrade isn't anywhere really available as the choices of front to rear replacements are so varied. the best bet is to figure out clamping force, pad area, and bias that you want and build a custom unit from the ground up. I have considered doing this with my Wilwood setup just to get rid of all the clunky stock braking equipment. A custom installed bias adjustment with a good set up rear upgrades will suit me just fine. And to boot, it will save some weight.

Just my 2 cents.

Tevenor said:

Unless you get EXTREMELY lucky, you won't have enough time before the destruction already has happened. The timing belts, for all their strength, disintegrate once belt integrity is comprimised. If the belt doesn't snap completely, usually the teeth with strip off the backing and once that happens, it doesn't matter of the backing is intact, your values are already bent.

Click to expand...

....and nothing's worse than bending your values.

Am I remembering wrong on this?

My recollection is that the bias on these cars is crossed between (RF - LR) <> (LF - RR). You have to completely rework the system in order to get a front to rear (RF - LF) <> (RR - LR) type bias system.

Tom

6. I can't find an upgrade kit for the rear brakes. Does one exist? I'm running StopTechs up front.
Powerstop makes them. I bought mine from hopupracing.com and I even think tirerack.com sells the kit now.

2. I plan to install a front splitter like Greg Collier's to (a) get front downforce (b) channel air up to the rad from underneath and (c) form brake ducts for cooling the rotors. The car seems perfectly balanced now, so I wonder what increased front downforce will do to the balance. Maybe I need a better rear wing. Problem is, I have a 1G (see photo), and can't figure out any way to put a wing back there without "ricing up" the car. Has anyone seen a decent rear wing for a 1G?
Maybe you could fab up some type of wickerbill as a lip on the rear edge of the factory spoiler.

terefic181 said:

Am I remembering wrong on this?

My recollection is that the bias on these cars is crossed between (RF - LR) <> (LF - RR). You have to completely rework the system in order to get a front to rear (RF - LF) <> (RR - LR) type bias system.

Tom

Click to expand...

You are right. It follows the ABS pathing. Assuming that we aren't using the ABS for the type of racing we do, reworking a front to rear bias is just a matter of setting up the right ratios. More or less, rip the entire system out and start from scratch, which really isn't as hard as you think assuming you do the math up front.

Tevenor said:

You are right. It follows the ABS pathing. Assuming that we aren't using the ABS for the type of racing we do, reworking a front to rear bias is just a matter of setting up the right ratios. More or less, rip the entire system out and start from scratch, which really isn't as hard as you think assuming you do the math up front.

Click to expand...

I thought about doing an adjustable bias setup some time back, but when I realized they were crossed, I dropped it for the moment. My car has a no ABS system. I take it you would just need to setup a new proportioning block with adjuster and run them paired correctly, through it. Is that correct?

Tom

terefic181 said:

I thought about doing an adjustable bias setup some time back, but when I realized they were crossed, I dropped it for the moment. My car has a no ABS system. I take it you would just need to setup a new proportioning block with adjuster and run them paired correctly, through it. Is that correct?

Tom

Click to expand...

Basically. You would also need to look at the brake master cylinder for incoming line pressure into the proportioning block. When I first started scoping out feasibility I started with basically the idea of replacing the entire subsystem ( MC, prop block, adjusters, rear calipers, etc. ).

The tough part is knowing the numbers to get the correction block and MC. I started working on it but pulled back as I had other things to work on and I already had a brake system that worked.

The extra bonus here is that if your replace the whole system, you can then get rid of the cable handbrake and go with a hydraulic handbrake setup.

Tevnor > Basically. You would also need to look at the brake master cylinder for incoming line pressure into the proportioning block.

Click to expand...

Sean,

So, would you say that as long as the line pressure from the MC is within the stock spec, you can use an adjustable proportioning valve in place of the stock one? The incoming pressure from the MC would be the same for both only with the adjustable type you would be directing the amounts differently to the front and back accordingly.

Thanx

Tom

(edit) spelling - Dang spell checker changed my word to something else, guess I shoulda been looking.

Tevenor said:

No kidding. If you need someone to come turn a wrench, build an engine, tweak a suspension, just fly me out.

Click to expand...

Where do I send the tickets?

slow old poop> housegsxMaybe I need a better rear wing. Problem is said:

some type of wickerbill [/B] as a lip on the rear edge of the factory spoiler.

Click to expand...

I have thought about it. That's what I thought I would do when the time was right. Well not exactly a wicker but a stand up rear spoiler out of aluminum or composite that could slide up and down (for height-downforce adjustability) the back of the original spoiler.

Hey Rich, here's my thoughts:

1. I agree that you may not have time to react but if you really wanted to do it the simplest switch would be a thin wire across the width of the timing belt through which you were checking for continuity(I work in mining and we use this principle to monitor for broken or frayed conveyors.).

2. The wickerbill or shave off the stock and get a wing like Greg's. You Sir, are definitely not a poser so it won't be rice!

3. Yup, definitely the Carbontrix, Just make sure your class rules will allow non-flush vents.

4. 5. 6. 7. I don't have enough experience to comment.

Phil

I've been talking myself blue in the face the last couple of days about cooling. I just took this picture to demonstrate that the area around the front to the top of the radiator is completely sealed. Just above the front splitter is an angled foil that directs the air up through the radiator, past the turbo, then out the vent through the top of the hood. This, plus having both fans on continuously keeps the hottest components well within reason...

Yee-haa!!

That's very similar to the front box i'm looking to build this year around my fmic. You can see her in ths pic that the front mount still leaves space on the sides to get air to the radiator. If i begin doing more road racing in the future then obviously things may need to change.



BTW Greg, was is that front splitter made of, looks to be carbon fiber, but I can't tell. I'm thinking about making one out of sheetmetal and adding a scoop to it in order to help a little bit on the cooling side of things. I'd also thought about building an undertray for the front and rear of the car to help in aero back there, nothing too drastic but some help would be nice. I just need to get to work on all of this sheetmetal fab this winter.

Kyle

That's one of the reasons I did the splitter (made of light weight fiberglass), to get the front of the car as low as possible to help displace drag before the air gets under the car. At this point the splitter sits about an inch and a half off the ground.
Every time you add a modification (especially out of sheet metal) you're adding more weight. If you can do it in fiberglass or carbon fiber you can kill a bird and a quarter or (1.2489) with one stone

Greg

Yea i'm just trying to do some research on carbon fiber right now. I've done a small amount of fiberglass work before, but carbon fiber is more expensive if you f-up. That's why I was thinking about using real thin sheetmetal for the radiator box and the front and rear undertray, and maybe something a bit heavier for the front splitter. Then once I get the whole carbon fiber thing figured out I'll make a copy of it in carbon fiber and sell off the sheetmetal versions.

If you do the under-tray in light weight sheetmetal you'll get deflection thus defeating its purpose. The front splitter you can lay down a few layers of fiber cloth then cut to form or for that sake do the same with carbon fiber...

Good point on the deflection

I think I'll start with fiberglass, then paint it flat black once its cured, it's about the same right

mavisky said:

Good point on the deflection

I think I'll start with fiberglass, then paint it flat black once its cured, it's about the same right

Click to expand...

I got my splitter sheet from extremedimensions.com (a sponsor) I think they cost about 75 or 100 bucks. It definitely saves a lot of time...

http://www.extremedimensions.com/3744.html (here's my sponsorship plug for the night)

Looks like you get a hell of a discount then as they list them as $299.

http://www.extremedimensions.com/3390.html

Even the carbontrix one is only $239, looks like we'll be trying the homebrew route unless you can get some sort of discount on those things.

Look here. (mine was free)

It's the blue sheet under the front bodykit...

http://www.extremedimensions.com/3950.html