Liam's Z4C race car project

[enuff_zed]

I plan to be concentrating on BRSCC Clubsport Trophy this year, especially as they have an excellent calendar. First round happens to be Snetterton (16 Apr)

https://brscc.co.uk/formulae/brscc-clubsport-trophy/

Excellent!
I'll see what I can do.

[TheDan]

I plan to be concentrating on BRSCC Clubsport Trophy this year, especially as they have an excellent calendar. First round happens to be Snetterton (16 Apr)

https://brscc.co.uk/formulae/brscc-clubsport-trophy/

Calendar looks awesome!! Silverstone GP, full Brands Hatch, Donington GP and Silverstone again!! You're gonna have a great time!

Any more plans with the car before the season starts?

[Sidewaze Samm]

I plan to be concentrating on BRSCC Clubsport Trophy this year, especially as they have an excellent calendar. First round happens to be Snetterton (16 Apr)

https://brscc.co.uk/formulae/brscc-clubsport-trophy/

Well as you've made the trek to Trac Mon, I hope you'll be making the somewhat shorter trip to Oulton in June and I'll be along to watch. So annoying that many championships are southern-centric and find it hard to get further north than Donington...

[axelleveau]

I just came across this thread a couple of days ago and just finished going through it all.

I have to say I am quite impressed at how straightforward your build is Liam, there is no waste of money on fancy parts, just straight to the point and it seems to work great for the class you are running
Onboard videos are nice, despite the fact it is "amateur racing" and has lots of different cars it seems like there are battles on track and you and others are not afraid to get agressive. I wish I could get into that

[Liam22]

Sidewaze Samm, I love Oulton, and haven't run the Z4 there yet. Can't wait for that one.

Thanks axelleveau.

[Liam22]

Quick update on winter upgrades.

Have always felt like the engine is strangled at the top end, and disappointed with the 250bhp peak power. The exhaust manifold and downpipe are really comprised for right hand drive vehicles. Partly because there are 2 catalysts packed in there, and partly because the steering column gets in the way.

My budget won't stretch to a custom tubular manifold but here's the next best thing.

FB_IMG_1643834697625.jpg (141.86 KiB) Viewed 961 times

Retaining only the 3-into-1 collectors, the rest of the system is all new. Comes into a 3" single pipe as soon as possible, with a race cat to meet regulations.

FB_IMG_1643834791781.jpg (155.54 KiB) Viewed 961 times

A single high-flow silencer in the middle and single 3" pipe all the way to the exit. No rear silencer.

FB_IMG_1643834716304.jpg (180.11 KiB) Viewed 961 times

Took it for a power run at the same rolling road I used before. +17bhp and a very healthy 267bhp at 6900rpm. Peak torque from 4500-6000rpm.

Happy with that. I also have a Superchips tune to try but wasn't able to apply it today.

[axelleveau]

Once again Liam your approach to go for best value for money is impressive! That welding is nice on here
Even if you do not want to go that way now, doing full manifolds in the future could just be a modification on top of that system

I just have one request: Can you post a video of it so we can hear how it sounds?

[lucasxdiniz]

Happy with that. I also have a Superchips tune to try but wasn't able to apply it today.

No sound clip?!

[jamesdi]

WE NEED A SOUND CLIP OF THIS BEAUTIFUL SPECIMEN!!!

[1536Z4]

Nice Liam and a good increase in performance .

What cell race cat have you used ?

Where did you have it made ?

Cost if you don`t mind giving me an idea ?

Thanks

[enuff_zed]

Looks good Liam
How does that fare in the scrutineering sound checks?
ie. Will I know you're at Snetterton from my living room 3 miles away

[Wursle]

Quick update on winter upgrades.

Have always felt like the engine is strangled at the top end, and disappointed with the 250bhp peak power. The exhaust manifold and downpipe are really comprised for right hand drive vehicles. Partly because there are 2 catalysts packed in there, and partly because the steering column gets in the way.

My budget won't stretch to a custom tubular manifold but here's the next best thing.

FB_IMG_1643834697625.jpg

Retaining only the 3-into-1 collectors, the rest of the system is all new. Comes into a 3" single pipe as soon as possible, with a race cat to meet regulations.

FB_IMG_1643834791781.jpg

A single high-flow silencer in the middle and single 3" pipe all the way to the exit. No rear silencer.

FB_IMG_1643834716304.jpg

Took it for a power run at the same rolling road I used before. +17bhp and a very healthy 267bhp at 6900rpm. Peak torque from 4500-6000rpm.

Happy with that. I also have a Superchips tune to try but wasn't able to apply it today.

Epic work as always Liam! a cheap modification that might be worth looking to for those extra HP is some MILVS. not massively expensive and can add a fair amount of Torque and power across the entire rev range. A company in the states StageFP do the custom mapping for these and have seen 250whp on our engines with very similar modifications to what you have already done!

They are also able to raise the redline to 7200rpm.

https://stagefp.com/product/sfp-n51-n52-tune/

https://www.bimmermilvs.com/

[1536Z4]

extra HP is some MILVS.

Don`t want to hijack Liams post so I will ask this same question in a separate one here viewtopic.php?t=134439

Hi Wursle

I have been thinking about doing this for a while and have read through the 39 page thread here https://www.e90post.com/forums/showthread.php?t=1329840 . Not in a financial position to go ahead with it at the moment as you also need the tune done remotely and I have already paid out for a remap . Have you done the mod yourself ?

[Liam22]

Wow - the MILV stuff is very interesting.

I had a cheeky shakedown race at Silverstone GP on Sunday. It was a last minute thing which meant going on last year's worn out tyres and marginal brake pads. A new race series for me, Snetterton Saloons (on an away day to Silverstone at a Britcar meeting). I was in the 2.5-3.5l class.

Damp qualifying, but the car felt great and noticeably faster. Unfortunately the ABS pump started to fail which meant I went from having ABS to not having ABS. Given that all my warning lights are already on (because disabled steering angle sensor) I didn't see this coming, resulting in a trip to the gravel trap...

I pulled the ABS fuse for the race but it meant learning the brakes from scratch. Thankfully it was dry, and I had a few locky moments but no real issues. In the dry, the car is now hitting 130mph at the end of the Hangar Straight and 2 seconds a lap quicker than the last time I drove Silverstone GP.

My son made a cool video https://www.youtube.com/watch?v=ySmZa22xDiQ


A few things to fix before its next outing:
1. ABS pump repair (I have the classic fault codes)
2. New RHS driveshaft circlip (same problem I had last year with the LHS). Driveshaft is popping out. Perhaps the diff/subframe is flexing???
3. Wheel alignment (getting dragged out of the gravel was brutal)
4. Replace bonnet badge (don't know where it went!)

[Zedebee]

4. Replace bonnet badge (don't know where it went!)

They are so expensive, someone probably nicked it!

Cool vid.