Truenotch

That’s awesome @Theo! They are very cool little bikes. Mine is very complete, which is lucky. It will still need quite a bit of love to get it back to its best and I’m looking forward to the resto. Mine will need a mild engine rebuild at least. It seems like at least one crank seal is misbehaving and I’m sure it could do with a set of rings or even oversized pistons. Is yours a high pipe or low pipe version? Definitely keep in touch if you find parts. I’ll do the same.

Front tyre is a 2.75-18 Shinko SR241 and the rear is a 3.5(?)-16 Shinko Holeshot super extreme knobbly.

Yep, the toolshed power files are legit. They're no makita, but are cheap enough and can take the abuse most DIY users will throw at them.

I’ve never pulled a set apart before, but ask the question in this thread, I’m sure someone can help:

Fuck yes. That little EJ and gearbox look perfect in there. Perfect recipe for a slalom slayer and a donut machine. Here's the car I was telling you about a little while ago that's a similar concept. It has a 2.4L Audi V6 and transaxle in the rear. I can't find many pics of the rear suspension setup, but hopefully it'll be at the track soon for more investigation:

I think we should give it a go if we're allowed. oldsocialdistanceschool meet.

Converting to compression struts is a cool idea. What are your plans for the lower arms and steering knuckles? True, but you don't want to remove all dive from the braking, otherwise all of the dive energy goes through the geometry and not the springs. Most things I've read say to go for a maximum of 80% anti dive to retain good driver feedback under brakes.

#smallbikeswingers

He wont.

Nice work, as always . Looking forward to seeing the new engine come to life. As for your suspension mods - the rear bar should make a huge difference to balance! There's always new challenges that come with adding components to racecars, but getting the front/rear roll stiffness balanced out makes a lot of sense. Interesting about the shock valving too! Sounds like it will be a completely different car to drive once they've been re-valved.

Fuck yeah, I'm in! Time to spend the next 6 months trying not to pull the red MX100 apart....

Yip, can point you in the right direction. Cardwells Racing Supplies should be able to supply the sphericals. They don't have them listed online, but here's the part you're looking for: https://www.qa1.net/automotive/suspension/accessories/bearing-kits . You can also buy them from Summit Racing, Speedway Motors and a lots of other USA websites, although shipping will be slow at the moment. As for the keeper spring setup. I don't have any pics of the setup on my AE86, but here's a set of MX5 racecar shocks I put together a while back. Under load: To add keepers you'll need shorter springs, locator collars (the silver bit you can see there^^) and a pair of keeper springs. There's a bit of mucking around and measuring to get everything right, as there's different lengths of main and keeper springs available and the combo needs to work for your chosen ride height. The first step is to figure out what you've got and choose your ride height. What rate are those springs and how much droop are you getting at the moment? It looks like the rear compressed about 50mm when you dropped it on the ground? In which case you've got plenty of droop at the moment, but the springs must be fairly soft. Give it a bounce and see how it feels. It might work out that you don't need keepers if you decide to stick with the current spring rate. Springs will usually have a rate marked on them, but if it's not there you can measure the diameter, length, number of coils and wire thickness to work out the approximate spring rate.

This thing Ian looking snazzy with the front panels in place. Have you checked or set up the bump steer on this bad boy?

I've been binging far too much DIY composite stuff during this lockdown, so figured it would be a good idea to re-read this whole thread. Man, there's some good stuff in here! @mjrstar - your dash looks amazing and I'm really impressed with the result since it's straight off the buck. I've been watching a few of this guys videos. He does quite a bit of infusion and vacuum bagging, as well as some hardcore aero mods on his own racecar and some wind tunnel work for clients. Pretty keen to build a foam cored carbon splitter panel eventually! I've got some front bumper mods that need to happen on the racecar. Will come back here and contribute my failures when it starts to happen .

I know. The rules are that we have to have window nets, but it would be easy for an arm to go vertical in a big rollover. I like having the roof open for an easy escape after a big crash. It's pretty cheap to run for a season. The current set of tyres has done around 8-10 rounds of racing, plus a bit of testing and they're ready for replacement (although the pace was fine at the last round). Brake pads last at least a season too. Fuel is 20-30L for qualifying and 3 x 6 lap races. So for a winter series at Manfeild the costs probably look like this: Entry fees ~ $900 for 4 rounds including transponder hire Tyres - $800 per season if you stretch them out for two seasons Brakes - $500 per season? Fluids - $200 per season Fuel ~ $250 (120L of BP 98) $2650 per season seems about right to me. They're one of the cheapest cars to run. Probably. I haven't tested back to back with the roof on/off. We kept it as a no-roof class to keep costs down and so the tall guys could build higher roll cages. Hard tops are going for $1500+ these days.

I took this car out for a race weekend back in September and had a goal in mind of winning an MX5 race. The car was quick and I managed to put it qualify in P2 for the first race. Bryce managed to get a good jump from the start and went from 3rd to 1st during the first lap. He pulled a bit of a gap, so I stuck my head down and chipped away at him for a few laps. The last couple of laps were good - I managed to get ahead of him and we were battling right up to the last corner. We crossed the line side-by-side and he won by a nose. Race 2 is reverse grid and it was busy as always! I got caught behind a slower car at the start and had to catch the other fast guys through traffic. Bryce and Matt pulled ahead and were battling hard all the way until the last corner.... When Matt overcooked it a bit, caught the grass on the inside and ended up spearing off the outside of the track into the tyres! This promoted be to another 2nd place finish. For race 3 I was set to start in P2 again and it was my last chance to get a win for the weekend. Unfortunately the car didn't make it to the start line because the diff let go! This was the original diff and we'd never opened it up. So it had lived a full life on the road (140,000ks or so) and has had 10 years of track abuse before letting go. It was a bit disappointing not to compete in the last race, but the weekend was still good fun! I whipped the diff out the next day and Dad pulled it apart. Yep, she's chooched! It's now been rebuilt by the local gearbox shop along with a solid spacer kit to get rid of the crush tube. I think the crush tube had squashed after 10 years of limiter launches . Oh yeah, we also fitted a window net to comply with the Mazda Racing Series rules for our summer racing:

They look harder than ~100lb to me. I’d say somewhere around 200-250lb would be a good rate for a road car depending on what you’ll be running up front. To run a keeper spring you’ll either need to run a shorter spring or “lower” the spring perches to account for the extra stack height of the keeper.

Rubber bushes might be a bit more comfortable for a road car and will be fine as long as the bushes don't bind up through the sweep. Although it's easy to order a set of spherical bearings later on if you change your mind. What rate are the current springs? I would recommend going to a shorter spring and adding a keeper spring to get a good amount of droop travel. Droop travel a requirement for getting a cert and it'll make the car ride better too.

As far as I know, it's fine to run the QA1 Proma stars upside down. The website doesn't say anything about it, but plenty of hotrod guys run them with the adjuster at the top. It will work fine as long as the spherical bearings have enough movement in that orientation as the shock swings through its arc (should be fine). The shock body could also get quite close to the shock mount tube as the suspension goes up and down, so take the springs off and swing the axle through its arc to see how everything behaves before locking it in. The only other issue is that you won't be able to use all of the height adjustment without hacking the shock mount area or running a shorter spring, but those issues can be overcome too.

Just had a good catch up on your thread. Nice work as always! Super keen to see the next steps. Those carbon trumpets will be choice!

I can't find a discussion thread for your race car, but is this your car? From a post on Facebook.

I’m teetering on the edge of brInging my bike back up from Palmy.... Things could go very sideways before then though.

I reckon this man might be on to something. Is it possible to force fill the rear hose or add a bleeder to the high point to test this? A vacuum filler as discussed earlier in this thread could be the ticket. Yowzer's diagnosis process seems logical also.