Turbo-4 '89 Mustang roadrace coupe.

[Russell]

Does your Miata make more power than the average miata or are you out driving them?

[Bob Holmes]

Our Miata is a tired out stock 1.6. I've thought about cutting out the floorboards and doing a Fred Flintstone.

Our 4 hamsters are tired and old. Its a great way to introduce newbies to the track. You have to hit your lines, carry momentum and forget the brake pedal.

The suspension and tires are what make the car special. And the setup is spot on. When the instructor came in with the newbie he said the car was too good for a beginner and had saved him from at least three spins. By the end of the day he was telling us that if he a Miata that he'd want the car exactly the way we had put it together and set it up.

But it needs more oats. I'm trying to convince my partners in crime to allow me to put a turbo on it.

[CDMBill]

I think the Miatas are a great starter road race car. When I did the Skip Barber three day at Laguna Seca to get my SCCA license a couple years ago we we're all in spec Miatas. Whee, big fun and we had a great mix of dry and wet. Open top cars in the wet really add to the fun. We raced in garbage bags over our track suits.

[Bob Holmes]

Whee, big fun and we had a great mix of dry and wet. Open top cars in the wet really add to the fun. We raced in garbage bags over our track suits.

When I went to SCCA comp school at Thunderhill, it rained cats and dogs. Luckily I'd rented a roofed spec Miata for the class. I really dug racing in the rain, it takes very fine movements and only about one input at a time. Driving with your fingertips.

Now my buddy that owns the Miata, doesn't like the rain too much. When we went to Russel at Sears Point, he was very confident about raining drive, until he spun the little red racer numerous times. He's had a phobia ever since. It was upposed to rain this weekend, and we purposely decided to go in order to get him over the issue. Damn, wouldn't you know it, perfect weather during the event, rained before and after. We even had a set of rain tires reserved at the tire supplier, just in case.

Bill, I owe you some info, I'll dig through my stack of stuff at home and see if I can find that cooling duct info.

[Bob Holmes]

Spent an hour with Geoff in the shop mocking up the external wet sump pump. Question, we can drive it off the crank or off the lay shaft that also spins the cam synch. I'm thinking that the crank will have more mass to dampen the cycling of the pump, whereas the layshaft really has very little mass, so the pump is more likely to influence the timing of the cam synch. However, the cam synch really only needs to be accurate to within about 180*. So I'm probably overthinking things.

Thoughts?

[Bob Holmes]

No thoughts but mine?? This isn't good.

[mike343sharpstick]

No thoughts but mine?? This isn't good.

Your eyeballs deep into Ford Turbo-4 tech here, I think we are all just eager spectators!

Funny, I took my Road Racing school in the rain too, on a motorcycle!
I can remember I was so nervous my shift foot was shaking like crazy just resting on the foot peg in pit-out and on the starting grid for my mach-race. I had ridden in the rain a zillion times on the street so once things got moving and I stopped thinking, all was good.

[Bob Holmes]

Funny how that works. If you have to think too much, you are screwed.

[CTX-SLPR]

Spent an hour with Geoff in the shop mocking up the external wet sump pump. Question, we can drive it off the crank or off the lay shaft that also spins the cam synch. I'm thinking that the crank will have more mass to dampen the cycling of the pump, whereas the layshaft really has very little mass, so the pump is more likely to influence the timing of the cam synch. However, the cam synch really only needs to be accurate to within about 180*. So I'm probably overthinking things.

Thoughts?

I'll throw some stuff in here, mostly questions thought... sorry.
What kind of pump is it? If it's a gerotor I'd think you'd be fine with the layshaft as long as it wouldn't twist on you. With a spurgear setup I'd be worried about the pulsations from the limited number of lobes in the pump impulse loading the shaft. Another thing to consider is the layshaft I would think would run at half crank speed so is that going to be enough for the pump design? From memory, not an expert here, gerotors run at crank speed and have smaller volumes per 360 but run twice as fast as a spur gear which runs at cam speed.

With a 4 cylinder and 90 cam degrees between fireing pulses I think you'd be safe on the cam sync trigger edge since there is no way you are running anywhere near that much advance or getting it too close to another cylinder to have it loose track of where #1 TDC is.

[Bob Holmes]

Well, I took an unplanned sabbatical from this project. But we're about to get going again. The engine and transmission are out of the racecar and sitting in my shop. This weekend we'll pull down the engine and get it boiled out, brushed and cleaned of any trace of the metal circulated from the torn-up dizzy-gear debacle.

Sort of forlorn looking: