Hyperblade

So went out for a shakedown with a new diff of 4.5 from 4.3 and the car looking like this: Some interesting results... It's all very well talking about PB's but in reality while I may hit a time, i'm far from consistent, and repeating it is often a matter of luck (bit between teeth chasing a car etc). So in the past i've always been around the 1.36:800 to 1.37:800 with the diffuser and splitter i was even more inconsistent and the laptimes were down, i just didn't feel comfortable with the car. I had a very unnerving experience going through pothole (fast left hand 150kish turn) where the whole car nearly under steered off the track, I've never ever felt the car like that before. So thinking being that the diffuser was working a little bit to well we pulled it off and just tried the splitter where i've felt I had an improvement in my times before. So so, nothing really different, less understeer but laptimes were about the same. I think where i previously thought it gained an improvement was just me driving better. So pulled off the splitter and just went back to basics, and did a 1.35.800, with consistent times between that and 1.36:500. The new diff made a massive difference, the car is just on song now, and still accelerating well at the end of the straight. So onto the last club day where i had a great day with my previous competition (Honda Integra DC5) unable to keep up: I took out the overall championship again and also won my class for the first time. So breaking it down, the diffuser is working really well, but the car isn't balanced with the diffuser on. I've always been told a splitter adds one second a lap, i've never really felt that with mine, i've actually never felt a major difference in the front end. So I don't think the splitter is doing it's job at the moment. I'm guessing the issue is the bonnet vent, I've now got a straight path from the top of the splitter through the radiator and out the bonnet. I think this is stopping a high pressure zone from forming on the top of the splitter. So i'm looking at changing the flow of air into the bottom of the radiators to create that high pressure zone. <

Thanks for posting up about the engine building, it's really interesting seeing the work involved!

My understanding is they are both your old parts! They are getting some good use now.

Not allowed to mount aero to suspension, nice try

Thanks @kpr and @Snoozin

Finished Version, just waiting on one mounting point to arrive. Ended up sticking out further then what i was originally planning as I moved it back from the diff for clearance. But shouldn't have a negative affect on the aero (opposite probably), and could still go out another 200mm within the rules! Can always cut it down later if needed Only concern is it getting hit by another car, so painted the back red to stand out...

Here's a better pic of the diffuser., strakes have been glued and screwed

Hah! should have seen my splitter after going into the gravel, came out with a rock garden on top of it, when they pulled me out the car started to submarine further in, still finding gravel in odd places. I have a spare splitter ready to go if i break it, beauty of plywood was a simple pattern and just drilling a few holes. It's a good entry to the diffuser, wish i had it as simple! Rear wheel drive makes it a lot harder. Hard to tell too on a hill climb, as opposed to a circuit where you can push the limits a little more without major risk.

I'm not a big fan of ali for a splitter, if you go off road it has tendancy to dig in and fold over on itself. The strength over a larger area means you have to put in a serious amount of support work, especially around the edges. (My splitter goes all the way back to the firewall) I think 4mm ACM might be better for this potentially, even 4mm plywood would be pretty good as you have a good structure for it and would be a bit more robust. That diffuser looks fairly aggressive! I've only gone for a 7degree angle (vertically only) as going for more really requires a good flow of air clean air to it (i.e flat floor) which i don't have. You might find if you made it less aggressive it will be more effective, also if you have a rear wing or gurney flap it can help it. Thanks for sharing, always good to see how others have done it!

Talking with someone in the know on aero, he recommended doing a double diffuser to deal with the air on top, i can't at this stage due to the fuel tank, but might be an option in the future. Currently it will still eventually find a way out, but just be a lot more inefficient. A better option might be to work on the lead up to the axle so you have less overall air going over the top. However you do need to be careful with Diff cooling then. Front: 400lb Rear: 350lbs

Yep, i lowered the pressure to the rear during the racing and got it driveable but it wasn't stopping as well after that. Just the act of stomping on the brakes forced the front to dive a lot and so the rear to go up, so required me to be a bit less aggressive on them to keep the car flatter (probably also need some harder springs at the front). Will be trying it on Friday, so fingers crossed it's dry. Hard to know if it will help as the interaction of the live axle makes things a bit more tricky for us to get the air leading into the diffuser right.

Thanks! The ducting mods made a big difference. I normally struggled to keep up with a competitor down the straight and instead could overtake him. I did take a bit of weight out of the car (alternator, doors etc) so i'm probably about even at the moment for adding it.. The splitter has had a big negative affect in the braking zones as the balance isn't right so i'm having to brake sooner then I normally would to keep the rear on the ground, but through the corners it is adding noticeable downforce and allowing me to turn in better. I'm hoping the diffuser balances it all out. Yep end plates and strakes added, just forgot to take a photo.

And finally to balance out the splitter I created a diffuser, again out of 12mm ply as that was easiest (prototype for now), mounting was really tricky but got their in the end. Have made some strakes for it and it's getting painted black to match splitter. It's height and angle adjustable, and is again quick release as i'm guessing it won't fit on the trailer. All ready to go for the last club day of the season Sun 5th May (Next weekend).

Got that all repaired and going into the last race of the season had a few things to sort out. Brakes were leaking at the rear still, so i pulled the calipers apart and found the seals were not the same size as the standard Toyota ones, really annoyed as they were done here in CHCH at great expense by a well known company. While I was at it I replaced the front ones as well just to be safe as they looked like they were starting to leak as well. I've had some 1mm Titanium brake pad backing plates made up for all the calipers which I'm hoping will protect the seals until I can replace the calipers all round with proper race ones. Been a bit concerned going into Winter that if I have to race in the rain that I won't be able to see out of the windscreen due to fogging (I do run anti fog) so I hacked the original windscreen venting to take a feed from a bilge fan which will take hot air off the floor (above the exhaust). Had the diff in to be checked after the hit it took, and have changed ratio from 4.3 to 4.5 so hoping that's going to give a nice boost at the end of the straight.

Of course the first club day I had the splitter on and got punted off the track (first time for me). From Behind: I was very lucky, minimal damage all round, his wheel hit mine and the rear axle took the brunt, he then ran down the side of the car and hit the front splitter which protected the front of the car, I ended up with a couple of bent brackets and turnbuckles, but actual splitter was in pretty good nick. Aero wise the splitter also had a major impact in high speed braking where i was getting huge weight transfer to the front and so the rears were locking, diffuser was now on the cards. However I have dropped my PB from 1:37.187 to a 1.36:200

Splitter Finally! got round to finishing off the splitter, I ended up going with 12mm marine ply (the lightest i could find) which ended up being 12kg total. I chose ply after looking at all the options, I wanted it quick release which meant it needs to be held up by the front and back with nothing in the middle. ACM was flexible and pretty heavy for the size you would need. I also wanted it to be easy to replace if it got hit for mounting I went with Stainless Steel Turnbuckles (8mm Jaw Jaw) with 8mm tie rod ends (all sourced from AliExpress). Some minor grinding on the tie rod ends and making up the ali rear adjustable brackets, and I now have a really solid mount. It's also adjustable in height and angle and takes my weight standing on the front. The splitter is all quick release and I can install in about a min, which is great as the car won't fit on the trailer with it.

I also decided to vent it through the bonnet. This had a positive impact on air intake temperature dropping it by at least 10 degrees, which gave a noticeable boost in power. Got cut down a bit... The whole unit drops on to some pins and then has some clips at the top, so possible to remove in under a min.

Instead the radiator decided it was time to start leaking. So time to replace it, I had also been concerned that adding a splitter would trap heat in the engine bay (In hindsight this is correct and I would have cooked things). I worked quite heavily on reducing the impact the radiator had on the aero by ducting the front and blanking off holes (with the overall goal of trying to keep the car still looking relatively normal...

So as per normal, my best laid plans when to hell and i had other issues to sort out before the splitter. Brake Cooling: Brakes have been a continual pain, they are just getting to hot, it's not an issue in races as I'm running good pads, but it means the life span of the rotors and the pads is a lot less then they could be, and I keep going through piston seals. So I made up some better cool air feeds, basically the air has no where else to go but through the disk, at the same time I went to a smaller hose diameter hose (2") which meant the whole thing didn't really work as I had planned. Polycarbonate rear hatch: Tried to get some weight out of the car to help the brakes, so went polycarbonate for the rear hatch. This was enough to get me though the last club day and I won the overall Canterbury Car Club Championship and came 2nd in my class (1600-2000cc) With the season over the intention was to get back to the splitter...

@Snoozin Which particular Wilwood Pedal box did you go with 340-11299 with 6.25 to 1 Pedal Ratio https://www.wilwood.com/Pedals/PedalProd?itemno=340-11299 or 340-13835 with 5.1 to 1 Pedal Ratio https://www.wilwood.com/Pedals/PedalProd?itemno=340-13835

Awesome info! I was thinking about heading in this direction just for the ease of packaging, to know it wasn't just down to rules is even better. Do you know what type/size of ITB's they used? They also look like bigger runners then standard into the plenum Here's a couple of pictures of it in place in the car that was sold on TM: It was quoted as having "New 280 + BHP (dyno Sheet) Lyn Rogers 3S-GE engine."

Yep that's similar to my line of thinking too, although I was going to mount to trumpets (as a backing plate, that was actually where i got held up as I couldn't find a nice mounting point) then have rubber gaskets to firewall/bonnet. Your way might work better. However MC, Clutch reservoir and brake lines make it really awkward.

Thank you, had tried that, but the aluminum was wicking away the heat to fast and I was trying to be cautious, so this time I got it smoking at 90c and that was just enough to get it out. Many thanks!

The fitting

So had a great day yesterday and broke off the bleeder adapter in the caliper. Then tried to use a screw extractor to get it out, but just not working as too soft. Anyone got any other ideas on how to get it out, caliper is aluminium so need to be really careful.