ForcedFirebird's m20 dyno thread.

[digger]

Apparently the stock crank damper does not like 8000 RPM.

what engine was that from?
All the other rubber bits degrade with heat, time and stress so this is no different. i bought a new damper for this reason.
i was in discussion with ATI to but not looking promising as the water pump and alternator drive is in the way so you cant get enough thickness

[ForcedFirebird]

Have you thought about using an Oil Accumulator and placing it on the rear of the car for weight distribution?

After reading this back, had another thought. Accumulators add points to our car in the series. We are at 495 of 500 points allowed, so no room for much of anything (want to say accumulators are 50 points or so, the e30 is already a 450 point car).

We ran one of the 180whp cars last weekend for a 14hr race at Sebring. We were running 8th of 72 cars and got a black meatball flag for a broken tail lamp, but was kind of a good thing (3hr to go for checkered flag, so it was about 8pm and dark). The driver mentioned he had no brakes, the front pads were metal on metal. Couldn't get the rear running light fixed, so removed the tail light backing plastic and stuck a flashlight in the housing (still had third brake and drivers brake lights operational, minimum 2 is legal). 23min pit stop dang it. Finished the race in 17th - only 2 BMW's completed more laps than us (both e46's) and the closest e30 to us finished 37th - which is an m50 swapped car in the unlimited class. Not bad for the little m20 that could. :)

[ForcedFirebird]

Apparently the stock crank damper does not like 8000 RPM.

[ForcedFirebird]

Have you thought about using an Oil Accumulator and placing it on the rear of the car for weight distribution?

Installed several oil accumulator setups as well as diff/trans coolers over the years, but honestly, unless you are doing rigorous long races, they hold up well in e30's. The e36 platform seems to heat up diffs far more than engine oil (more tire grip, more power on the same sized diff carrier/ring set, heavier car). A very simple oil cooler and small e-fan or ducting goes a long way.


The current e36 sprint car sees oil temps matching, or lower than coolant temps, in the neighborhood of 169°f maximum. Took 2 1st place and one 2nd at the last FARA 300km event in homestead Miami two weeks ago.

[darvo]

Have you thought about using an Oil Accumulator and placing it on the rear of the car for weight distribution?

[ForcedFirebird]

How valuable would an audible alarm be for oil pressure? Or is it too noisy to be heard in a racing environment?

If you were able to program an alarm that was rpm dependant it might be useful

On a rally car i was involved in we had a trailer stop light on the dash attached to signify low oil pressure.

We have a gauge in place of the stock dummy light. The car has been running without a baffle/scraper or light since 2013 on that car, but it has never been this quick (rule changes in the series with points/lap deductions vs modifications, better tires etc). Will be installing an oil light, and baffles/scrapers in the oil pan for the next event, needless to say. We were over 4 seconds faster per lap vs last visit to the same track, and a few of the same drivers.

[e30davie]

On a rally car i was involved in we had a trailer stop light on the dash attached to signify low oil pressure.

[digger]

If you were able to program an alarm that was rpm dependant it might be useful

[earthwormjim]

How valuable would an audible alarm be for oil pressure? Or is it too noisy to be heard in a racing environment?

[ForcedFirebird]

Again, not sure that car will go back to the dyno anytime soon, but will see what I can do.

Welp, it definitely won't be dyno'd again. Raced the cars last weekend and had a couple minor issues - but the 168hp car definitely pulled on the 180hp car in the straights - but the 180hp car ended up making better lap times due to it having coil overs - pretty sure the diff was causing some serious parasitic losses on the dyno.

After 315 laps on a 2.6mi course, I was driving the 168 hp car and it lost oil pressure in a high speed right hand sweeper with 5min left after 14hr of racing. I heard the noise/knock, looked down at the gauges and saw the oil pressure at 10psi and dropping fast (was at about 3500rpm). Got the car back to the trailer and pulled the dip stick, it was almost a quart low. Our fault. We hadn't checked the oil the entire race as we had a small couple small issues - fuel filter clogged from surface rust in the tank (it sits a lot), and later on in the race the crank sensor started acting up. We got so zoned in on these items, we never bothered to check oil level.


At the Road Atlanta circuit, the 168hp car was able to put down a 1:50 and the 180hp car put down a 1:48 - both on 200 rated street tires and mid-level drivers. Fastest e30 of the day put out a 1:45 in which I had the pleasure to lap with on my last stint, that car was just as quick on the straights, but they clearly had a much better driver (or suspension) as he was able to shake me in the corners.

[digger]

He was going to remove the rotating assembly from it

[E30-325iS]

Nice Dyno #'s! I recently purchased a set of 12:1 85mm Vac 885 head pistons for a 89.6 and 135mm stroker build but the m54 block I had in mind was thrown away before I got to it.

The pistons are 12:1 for 89.6 and 135mm rods, but the m54 block disappeared after Hurricane María.

I might be missunderstanding what you are trying to say but you can't put an 885 head on a M54 block.

[darvo]

I have an 89.6mm S52 crank for sale if you're interested. Can ship to your island if you pay for it. Crank was recently polished within spec, balanced, and even comes with the snout spacer you'll need for the M20. Message me if you're interested in it

Pmed for shipping quote

[darvo]

He needs the 84mm and has the 89.6 (which is putting his pistons way out of the deck - hence the .100" gasket plan).

The pistons are 12:1 for 89.6 and 135mm rods, but the m54 block disappeared after Hurricane María.

I only got a E block laying so, I was looking for 139mm rods to use with a 81mm to match the deck height but only found 138mm to use with the pistons.

The 0.100 gasket is to lower the compression to 11.2-11.5, I would like that CR with my current cam.

[digger]

He needs the 84mm and has the 89.6 (which is putting his pistons way out of the deck - hence the .100" gasket plan).

His pistons are originally intended for 89.6 so he should get that but he'll need to get the 135 rods to go with it.