Rhyscar's Toyota Levin - 2zzge Touring car - finished*

[mjrstar]

To reduce understeer just get the rear to toe out under compression.  

You have to lean on the rear tyre a bit on entry by being slight less smooth but it seems to work.

 

 

 

[Rhyscar]

@mjrstar I run at least 2-4mm toe out total in the rear, and a bit less in the front. Doesn't seem to change too much other than initial turn in. I've run up to 6mm in this car previously and it was fine. 

 

The more I think about it, the more interested I am in results of the corner weights when I get around to it. I theorise that all the stuff I've modified such as sitting 2-300mm further back, reducing front weight by having a lighter engine etc means I've got a more equal front/rear balance than most FWD cars (particularly Hondas), while keeping overall weight down. Will be even wilder with the co-driver installed. 

[Truenotch]

19 minutes ago, Rhyscar said:

@mjrstar I run at least 2-4mm toe out total in the rear, and a bit less in the front. Doesn't seem to change too much other than initial turn in. I've run up to 6mm in this car previously and it was fine. 

Does the toe change through the stroke? I think Matt's referring to using bump steer to your advantage (common in the Honda world).

You'd need to do a bump steer sweep and scratch your head a few more times to work that one out. 

[Rhyscar]

There isn't much movement as it's got two parallel bottom arms unlike a Honda. Last time we string aligned in moved the wheel 50mm and bugger all toe change (1mm or so each side)

[mjrstar]

You'd think if you had it working just the outside wheel with some toe and the inside wheel off the gound it'd want to rotate a bit.

I reckon it would be a tricky combo to build something that excels at nz style hillclimbs as well as smooth circut work. I'm confident my car would do pretty poorly at a circuit. 

I've put a video in the video thread of an event that has a set of bumps and a few crests to deal with.

[Rhyscar]

You're 100% right. All the Targa guys hate doing stages at the tracks as part of the events. All these mega-built cars setup for all manner of bumpy roads and are massive boats on anything smooth. 

[Honda Ass Dragger]

19 minutes ago, mjrstar said:

You'd think if you had it working just the outside wheel with some toe and the inside wheel off the gound it'd want to rotate a bit.

I reckon it would be a tricky combo to build something that excels at nz style hillclimbs as well as smooth circut work. I'm confident my car would do pretty poorly at a circuit. 

I've put a video in the video thread of an event that has a set of bumps and a few crests to deal with.

Hillclimb & Circuit are Chalk n Chese

Friend has a AE86  for Hillclimb's he running at 3/4kg spring on track its a 8/10kg spring

 

[Rhyscar]

Lots of small jobs being ticked off the list to finish this thing. Hoping for some track time in the next month or two. 

 

Redesigned the shift levers and sent them off the be Aluminium 3D printed in China. These are much wider, and take 2x skateboard bearing per lever, so expecting the axial stability to be much improved. Quite an interesting problem to solve the mechanical strength when you're not constrained by manufacturing technique. Will be interesting to see how these turn out - all the thin sections are 3mm which I think will be plenty. 

 

I picked up a second hand set of Hankook RS4 a while back, with the idea to use them as road/storage tyres. Didn't like the idea of my car sitting on good Nangkangs all day long + trailering etc. 

 

Got the car out to Frankton thunder to support my Tyre shop who look after me very well (I tend to buy a lot of tyres from them too!). Good chance to get the Family out. 

 

 

Finished off the external pull cable system for my fire extinguisher. The common issue with external cables is they aren't very waterproof, and end up rusting from water ingress (but still WAAY more reliable than a electronic push-button!!). So I decided to split the cable under the dash, so I'll only need to replace 1m of cable instead of 4m. Joining the cable was an interesting challenge I had to get creative to solve.. 

 

 

I've got some 5x racing bump stops showing up this week hopefully. All going to plan I should get these in before toyotafest. I had initially hoped to do some track time, but these tight timeframes and the format meant I pulled out and will try to do a few basic track days at Hampton Downs in the next month or two instead (and mayne a sprint!). 

 

It's my birthday this week, so taking the day off work (kids at daycare, wife at work woohoo!!) to put the finishing touches on this - if the 3D print and bump stops turn up that is!

[Rhyscar]

Next job was a bunch of missions to retain my airbox filters, and to glue my strut brace together (fully functional now - no longer a show piece!)

 

So I wacked an M4 rivnut through the carbon, coated inside and back with some epoxy (same as strut brace stuff), and made some nice stainless tabs to hold the top. I think it looks tidy enough?

 

I also fabricated an alloy plate to hold the bottom of the filters in place. This attaches/removes with the grill. I also intended it to seal off the airbox entry from the area behind the bumper. I suspect this will funnel more air into the filters rather than filling the low-pressure void behind the bumper. 

 

I did a small test of the HPR25 Toughed epoxy on some spare parts I had lying around. Cleaned them coated both pieces with a small lick and stuck together. Went really well - after 24hrs I couldn't move/budge it (1wk to cure fully), and I found it cleaned up nicely with Acetone so I could manage any extra blobs. 

 

Made a few blobs (better to have too much than too little!). I glued in in-place so all the angles were exactly right. 

 

 

.... and the finished result tidied up. Pretty happy with the result and I can't wait to see how stiff it is when set. 

[Rhyscar]

Shifter linkages showed up. Off to @Geophy tonight to get machined for a shrink-fit onto the skateboard bearings (this may be a little over the top, but may as well). 

Very impressed with the design. I can't bend/flex them in any direction, so they should work. I realised I made a mistake with the large one though - it's approx 40-50mm shorter than the previous (which I changed to reduce force, but didn't think about throw grrr) - this will increase the side-side throw on the lever. I'm hoping it has enough range spare to deal with it. If not, I may need to reprint this one.. all part of the development process

A little disappointed that the print quality was a bit poorer than last time, maybe due to some of the smaller features, but won't impact functionality - will get in touch with supplier and see what they want to do. 

[Roman]

The bits that look dont look so good will be from where they have had to use supports and then grind them off. 

It might have been that the simpler shape on your last parts meant they didnt need supports perhaps. 

The good thing though is that you never need to look at your shifter, because it's totally intuitive to be shifting gears backwards 😄

 

[Rhyscar]

That is a good point on both fronts. Who is silly enough to think it was a good idea?? 

[GARDRB]

Give an engineer stuck in a wet paper bag some scissors and he'll design and build the bag opener 1000 to get out.

[Rhyscar]

Big thanks to @Geophy for boring the centres out, and shrinking in a set of fresh skateboard bearings. This may be a bit of an overkill as it puts unnecessary pressure on a small bearing casing, but there's definitely no way they are coming out! 

 

Throw turned out to be perfect - selects all the gears, more accurate, and less slop in the action. All round a great upgrade. God damn it looks great too. 

 

 

Now I want to re-do the 2x remaining levers to a clevis-style dual bearing arm. 

[Rhyscar]

Levin got out of the shed for Toyota GR festival. Good to have it in it's finished form - itching to get it out on track for a proper shakedown/testing now!

All in all, great day out. Heaps of positive comments from people who have been following for ages. Great milestone to reach for sure. 

 

I love seeing my car through eyes that aren't my own. Always looks way cooler in other peoples pics. 

 

 

 

Got a few casual runs around during the parade. Gave it the beans once or twice. Put a massive smile on my face. 

Shifter was phenomenal, the gears were spaced slightly different, but very positive feeling engagement and felt natural. 

 

At this point, it's a better show car than a racecar. Time to change though - bump stops have arrived, so I will whack them in one night this week.

4nR is running a derp looking event the same weekend as Taupo supercars that I'm thinking about. Dumb format (4x 15min grip sessions over 2days, and a bunch of cruise sessions), but would be a great chance to get 5000x more use than it's had over previous years. hah. Just got to figure out if it's worth committing a whole weekend for that much track time, however, other trackday/test session options are limited for next month or two - my wife is doing some travelling (Queenstown and USA), so I've got a lot of parenting to do in April/June, and we're planning on competing in rally Waitomo with the Ke20 Corolla in May. So if I don't get some track time in next few weeks, it might not be until July!  Bloody first-world problems. 

 

Toyota fest was Sam-approved. South Island next year?? 

 

 

Had great barry yarns with Richard with the Toms Corona BTCC car. Unfortunately I didn't see it run as he damaged a radiator, but good to look over the engine bay and details. Makes me feel pretty proud of the packaging I've achieved. 

[Rhyscar]

Just when I thought this project was finished... 

So did some more stroking and calcs to work out where new bumpstops will fit. Figured out rear shocks only moved 28mm before hitting the wheel well... So not good result considering I've raised it approx 20mm recently - meaning the only logical thing to do was cut it up some more. The rear wheel well has an odd shape near the outer lip that supports an internal brace to strut towers and roof pillars.

 

So I started cutting, and this is what I found. Probably adds a lot of strength, but it's a PITA for what I'm wanting to achieve. 

 

Peek a boo

 

Ordered a trailer guard and turns out it's the perfect dia for the 17" wheel. 

 

Tacked in place for now - tricky shape to get right. 

 

 

So here are the before and after stroke length and bumpstop height to limit the wheel before making contact with the near inner guard. The new 5x bumpstop is what they call a 'medium' - starts at 120lb and increases exponentially to infinity. Full length 36mm, compressed 12mm. 

Approx 62mm droop, 50mm compression. Much better. 

 

 

 

Now onto the next side - it's a little bit different as no fuel flap, and access on this side of the shed is a little average, so taking some time to get it right.