Truenotch

So... When's the next rally????

It's a good battle eh. Reminds me of racing your old man in the Corolla and having almost exactly the same laptimes, but different speed in lots of areas. My car was geared just right for that track, so I was able to launch out of the corners better. The City is loads quicker down the hill into the carousel.... We both hit a top speed of ~150 on the front and back sections of the track, so peak horsepower/speed seems about the same. Pretty keen to go door to door racing against the City. We should get a chance to battle at Highlands later in the year.

Look at my massive semi I have three more somewhere too. They should be good for the Coronet Peak Hillclimb in November.

Club sprints are like that eh... People forget to look backwards, no matter how much you talk to people and they agree to move out of the way. It was fun though! Even though the traffic killed a couple of runs for ultimate times. Cheers man, it's a nice feeling to be back out there. Looking forward to more events over summer.

Chase cam from the City in run 3. Skip to 1.05 to see a hairy moment passing a Mini.

Took this for a run at Highlands on Saturday. The Central Otago Motorsport Club run a sprint on Track C each year. It's reverse direction with the addition of the whoops and an extra corner through the forest, so there aren't many straights and it favours good handling cars. Suits me! It's a pretty busy little section of track... I'd say it's the coolest format of any sprint I've done in ~20 years of motorsport. Here's an external view: My workmates Brandon and Taz were running the B18CR City, which also suited the track really well. We ended up 1st, 2nd and 4th out of the 48 entries. Not bad There's a couple more videos on my YouTube channel if you're keen to see more: https://www.youtube.com/@truenotch/videos

That's a really consistent whistle eh! My guess is one of the vac ports in the throttle body is whistling as the flow runs past it. Kinda reminds me of a few 4AGE 20v powered cars that get a whooshy whistle at wide open throttle.

Moved the discussion posts here for you @GARDRB

The J pipe thing is really interesting eh. I've been researching them recently - they work by bouncing a soundwave back against the flow that cancels out the frequency of the drone. Most people use a sound frequency app to see where the drone peaks, then create a capped off J pipe that's roughly 1/4 of the length of the wavelength that's causing the drone. You can also a helmholtz resonator, which is a bit smaller and more bulbous. They're more compact, but harder to fabricate and calculate than a 1/4 wave reso. Jump into the muffler thread, there's a few good vids in there. It's really cool that your little J pipes made a difference btw @yoeddynz

I have a silly question for @cletus or any WOF inspectors out there. Lots of factory option Bilstein suspension is "circlip" style with an aluminium spring perch like this: I have a set of adjustable coilovers like this: Hypothetically, if I spun the thread off and turned these into "non adjustable" circlip style perches, would I be able to get a WOF without a cert (provided it looked factory).

If you do it right you'll also be able to use it as a dyno while you drive.

The headers decided to start leaking at Teretonga, which probably explains all the flames out the rear end Pulled them off to inspect, and there was a decent sized hole in #3. It would have been pretty thin from port matching and must have cracked and blown out. @eke_zetec_RWD made these headers for me back in 2010, so they've done pretty well! I was planning to give them a. cleanup anyway. They came up pretty good after a quick sand blast: Welded up the affected area and tried to use as little heat as possible: And a quick lick of high temp paint: Then I spent this afternoon wrapping the headers (another job I've been planning to do for over a decade). I won't be in a rush to do another set.... It's a fiddly job. Should help with under bonnet temps a lot, so it'll be worth it. Back on the car:

Haha, there's a few things to it. 1. First day driving my car at Teretonga and only my second day ever on that track. 2. 200/580-15 slicks are a bit too small really. The City runs 235s. 3. Aero def helps in turn 1, 2, 3 4. My car jumps over the braking bumps and the City is way more setled. I'll. Be able to dial that out with some setup work 5. I had a flu and was just kinda not there, but still gave it a good crack I could go way faster round turn 1 too, it's just scary braking on an angle from 200kph over bumps into a looooong radius corner

Yeah man, I'm planning to do Coronet at the end of November, along with a few other race meetings at tracks around the south. Tentative events: October 5 - Highlands Sprint Series Nov 2 - Highlands Lemons (driving the City) Nov 30 - Coronet Peak Hillclimb December 7-8 - SS Cup Teretonga January 25-26 - SS Cup Levels April 5 - Highlands Sprint Series + SS Cup Hopefully I can find a Ruapuna event to slot into. It'd be nice to tick off all 4 SI tracks.

Onboard vid from the City (GA2 City with B18CR, 17x9s with 235 Nangkang AR1s, M factory close ratio kit etc etc). The City is ~185hp at the wheels (about the same as my car) and the weights are similar, so they're pretty well matched .

Packaging will be a problem for you eh... One of those links I posted earlier talked about the difference between a helmholtz chamber and 1/4 wave resonator. The 1/4 wave reso seems easier to install and set up because it's more about length, so you don't need as much math to figure out wave timing etc... And you can easily cut and shorten a pipe to get it just right . Helmholtz chambers are a lot more compact, but you'll need to do more calculations or revisions to get it just right. They also have the added bonus of looking more like a willy.

Wild weekend! Great to see everyone. Thanks to Karl, Harry and the crew for organising a banger of a weekend and Katie and Jay for the Wambulance loan. We felt like the silliest men in Hanmer all weekend and it was great Checking the vitals on the Wambo: #builtnotbort #bortwarner35transmission Cutting cheese with a cracker....

I reckon building a 500mm-1m adjustable slip joint trombone would be a cool science project on a super droney car.

Another interesting one is the Mugen loop muffler for DC5 Integras. This passes through the chamber twice, so is a cheat code for getting extra exhaust length and muffler length in one hit.

Has anyone here played with 1/4 wave resonators? They aren't a racecar thing, but it sounds like a really effective way to get rid of drone for a road car. They're basically a dead-end branch that comes off the main system. Pretty simple to fabricate and there's a few calculations you can do to work out volume and length. Apparently Darren at Pitstop in Hastings has been nerding out on them and installed one on a friends supercharged Vitz. It went from a painful drone to perfectly pleasant. I know @Roman is keen to experiment with them. Sounds like it'll be a fun thing to try. I haven't read these yet, but for safe keeping: https://wilhelmraceworks.com/blog/drone-reduction https://grassrootsmotorsports.com/forum/grm/problem-exhaust-drone-solution-side-branch-aka-14-wave-resonator-or-helmholtz-resonator/129212/page1/

It sounds great man! I can't wait to hear it at full song. Here's some info about engine break-in. There's also a break-in module in the engine building courses on HPA that I know you have access to .

Haha, it's not his, but there's a great story behind why he did the SC conversion for free

Haha, sorry @anglia4. It only fits upside down.... the rear clip hits the firewall if I go the other way.