E5TUS - 2023: Some turbo tinkering & Hillclimbing
Turbo Mini Forums

Ok, so the mini was in no state to make my planned journey, but I was loaned my Dad’s Vitesse out of pity and had a good cruise up and back. Asides from throttle cable being dried out and sticking, it ran like a dream, only the four speed box in it, although we have acquired an overdrive gearbox which would be a nice addition for cruising.



The 2 litre still has plenty of it’s 95 ponies left and it’s a very comfy ride compared to the mini.
Ah yes, the mini. That little bastard continued to occupy my thoughts for my week off, plaguing any free moment with “got fuel, got spark, why won’t it run?”

So to recap: Ran like crap after battery cable issue. Found a handful of suspects, but no dice.
Fuel pressure ok, fuel pump flow ok, ignition system all ok (spare EDIS, coil, plugs and leads all alternated but no change), timing was all good and light confirmed the output of megajolt.

Carb was main suspect after all the initial red herring investigations. Found the piston and dashpot were sticking, a slight inclusion was causing interference. I’m aware you are not supposed to use abrasives on the inner surface of the dashpot, but with it causing an issue, I didn’t see much of a choice. Was very careful not to go mad and fettled the offending area. It changed the problem from idling but not revving, to not running at all.

Ok, so a step backward, but it was definitely causing the rich mixture before as the piston wasn’t able to seat back down fully.

Went through the usual checks but couldn’t get it to run unless I pulled the piston up manually using the damper. So, I figured I’d taken too much material off from too big an area and now the piston wasn’t lifting. Not sure if everyone’s keeping an eye on various parts, but the carb bits are getting pretty damned expensive. Burlen wanted £300 for a new piston and dashpot. Managed to find a NOS assembly for a rover V8 for £70 so waited for that to arrive.



Bingo, back to running with a little throttle, but couldn’t get it to idle, even with full choke. Again, ran with piston raised and throttle. This made me think that the piston wasn’t rising, so I went back on the hunt for an air leak inlet side. I’d applied pressure and vacuum to the BOV before, but only the pressure side off the plenum. But the signal side was able to draw air either way.



Little bugger to find, but there was a leak.

Blocked the BOV take-off and signal line and it started ok. Unbelievable. Did not realise how sensitive the HIF44 was. But hopefully I can now sort fuelling and finger’s crossed I'm good to go.

Unfortunately, I’ve already pulled out of next weekends events at Gurston Down but still a way to being happy with everything so probably the right call.

So between the dump valve leak and suspect part lean off pipe, there was considerable inlet air leakage. Now I've remedied these issues, and it runs. But it's rich, very rich.

I assumed this was due to last tune and needle adjustments whilst air leak(s) present, so changed the profiled BDA needle for a bog standard BDD, still rich, and actually worse on HC count.

I know rich is better than lean, but I'm far too rich for the MOT criteria, Even with jet fully up I can't get below 10%CO and 3000ppm HC. So still a way off.

I've ordered another service kit, as my spare jet got pilfered for another job. I can only think that the jet has worn, and is letting in too much fuel regardless of needle height? Also going to change the bimetalic strip and plunger as they are probably original items and unknown history.

I've checked that fuel doesn't flow out of jet with dashpot off, so needle valve/float is ok, float has been checked for height etc.

I've tried my original spring, new yellow and new green, all vary the result, but never enough to get the idle mixture above 10:1 AFR. Changed the oil thickness to slow the rise, but again, not enough and I'd like more reaction for acceleration. Sticking with the 20wt SU oil for now.

I've never had a problem with it being rich before, usually the opposite, so I suppose a nice problem to have. I've been scratching around searching but asides from choke seals (which I'll do this week), I can't think of anymore suspects or remedies. Any help appreciated.

I had something similar with mine, on idle it was just pig rich. I wound out the mixture screw all the way and it would raise the jet enough. I put a washer under the bi metallic strip for more leverage

Choke assembly, got to be the culprit...

Bloody thing has been trying my patience! Fingers crossed

Last week I was still awaiting my service kit so called up Burlen only to find the service kits and rebuild kits out of stock. I’m only 40mins away, so took a jaunt on the motorbike out to see them. The staff are great there and threw together a kit of parts for me. There is currently no stock of the needle valves so that was stopping the kits being available.



I’m sure the choke o-rings would have done the job, but I replaced the jet, bi-metallic, float and damper as they were all worn or of unknown history. All back together and it started straight up. Using the two turns from bridge as base setup it wasn’t a million miles off, needed a bit of leaning out to produce the best figures I’ve ever seen from it.



Took it up the road and it was a bit hesitant on heavy acceleration. I had left the green spring in, replaced it for Yellow and it was happy again.

More for my record than anything else:
- BCA Needle (polished from stations 9 onwards)
- Yellow spring
- 20w oil
- T-Piece trick
- Part lean off connected



Very happy it’s back together and performing, but equally annoyed with myself for not staying on top of the little bits that had clearly been degrading. Mad that there were air leaks and over-fuelling in the right amounts to counter each other.

Disappointed to have missed Gurston Down weekend, losing the two events at another venue mean I can’t hit the requirement for the Clubman Cup I was working towards. But I’ve secured another 3 events at Wiscombe with another 2 available so I’m concentrating on the Wiscombe Challenge Cup.

It’s the British Hillclimb Championship at Wiscombe Park this weekend, I’m lucky enough to have an entry to the Interclub events both days. Always a good weekend and great to see the quick boys go up the local hill. Then sprint at Goodwood next weekend. Can’t wait to get some seat time.

Why are you using the T piece trick? I thought that was used to pressurise the float bowl.

I've just bought a new bimetallic strip for mine, along with a couple of other bits. Realised the car won't be out this year so thought I'd do some bits that I haven't been happy enough with.

Why are you using the T piece trick? I thought that was used to pressurise the float bowl.

I've just bought a new bimetallic strip for mine, along with a couple of other bits. Realised the car won't be out this year so thought I'd do some bits that I haven't been happy enough with.

Mixed bag of weather at the weekend, but car was all good, so I can put up with the occasional shower.

Journey on Friday night was nearly 3 hours, usually 1.5, bloody tourists! Then came a gutting blow, diversion 3 miles from venue, all the traffic both ways sent down a tiny country road. I made good progress, pulling in though where possible and letting them pass en mass. Third car into a row of them clouted the rear light assembly on my trailer, my lovely new, shiny, beautiful trailer. I know it’s a tool and won’t stay perfect forever, but first journey? Really?! The one silver lining is it did a lot of damage to his car, and I bend the light box back later. But still. Wanker.

British Hillclimb Championship weekend at Wiscombe Park. Big boys out to play, practicing on Saturday and timed runs Sunday, with two top 12 run-offs. The weekends activity was interspersed with two days of interclub events. We had a decent championship class of 11 entries, but lost one due to isolation and another due to lack of alternator. Here’s a few of the class:











Saturday saw bouts of rain, but we had our practice run in the dry. First proper chance to use the car since I switched to 10” and fitted the lightness. General impressions were good, less grip than the 13x7 avons, but that was more likely down to newness of tyre and first run conditions. The back end hopped round the first corner, which prompted a change of tyre pressures after. Generally lighter on the steering but the death by torque steer is dramatically reduced. I used to fight the bugger back straight after each gear change and getting back on boost, but it’s completely different now. Second gear is no longer enough through the esses, so will have to move back to using third. It was happy up the straight at WOT, which I was happy about given the faff with fuelling recently. 51.19. Happy with that for first run on new tyres.

Dodged a quick shower between practice and first timed run. But reports back from the other drivers were that grip was improving. I had a slower launch but caught up by the split, the car didn’t hop round wis corner so I was happy with the tyre pressures. Managed to shave a second off in the top half of the hill, mainly down to grabbing third in the esses I think. 50.05. Given my best timed run before this year was 50.12, I was very happy. Still loads to gain, tyres getting better by the second and figuring out how it all feels. One thing that really surprised me, the brakes, holy shit, so much better than my old 8.4” vented setup. To the point, if I change down and brake as I used to, I feel I'm too slow in the corner or too early. There’s some balls to grow, but time a plenty to gain as my confidence grows.

The worst of the rain came in the lunch break and lucky for us, we had 100 cars go up the hill to dry the tarmac before our second timed run. I was chatting with one of the lads and realised his PB was 1 hundredth quicker than his last run and it was a hundredth slower than my PB. Game on. Felt it was a rough run, I was a bit all over the place, but matched my PB 49.62 but this time it counted as the last time was a practice. First ever day of continuously improved times. Launch was 4 tenths better than anything I’d managed previously and the split is nearly a second down. I know I'm losing most of the gains in the two hairpins, much to work on with the braking, but it’ll come together with some more seat time.

My dad has had a couple of good events at Llandow and Clay Pigeon whilst I’ve been messing with the car and clearly found his mojo, 48.19 making sure I was cooking dinner again.. but it’s a game of two halves as they say.

Sunday forecast wasn’t looking too pleasant, but as Saturday, it came and went. Unfortunately for us, the rain came every time we were due a run. Very slippery off the line and a bit greasy in the trees. My best time in the rain previously was 55.07. There was a noise as I approached sawbench corner but I seemed to have steering and drive so carried on up castle straight. On my way down a marshal flagged me down and handed me a grille button that fell off and I must have run over. First practice I managed a 54.71 so not bad.

Stayed dry for most of the national boys and then as we geared up it came in heavy. It stopped for the run but the track was fully wet. I came the closest I've ever been to the bank after sawbench and I think all our class suggested they nearly ran out of track at some point. Improvement to 50.92, car feeling good.

Dad was second up on practice but I was ahead of his 52.30 on first timed run. All to play for. Last run was another wet run little less traction off the line but a clean run up the garden path to secure 50.85 a new wet PB, taking over 4 seconds off May’s time. Dad struggled with grip around the big corners dropping his time to 50.94.

A quick check over everything during the week and off for my first attempt round Goodwood. I’m apprehensive about this one, bucket list track and a quick place too, but keen to see what the car has top end.

Edited by e5tus on 10th Aug, 2021.

Gutting about the trailer, can't make it up. Sounds like it went better afterwards.

I'm concerned my gearing will be a touch short next weekend, don't fancy grenading it on its first outing.

Got to survive a rolling road visit on wednesday first.

Less the trailer incident, Im genuinely pleased the weekend went without hitch after the fueling debacle.

Shane

I used a different mounting position for my GoPro, didn't realise until I was seated and harnessed in, I can no longer reach it. So took very long videos and the battery died before end of weekend.

I also did forget to switch the invert mode off now it was mounted up the right way. Managed to flip the video, but it got cropped in the process.

Anyway... Here it is, my best run of the weekend. Very nice to see spectators again, made quite a difference, and although not there for us planks, it did make you feel like a big deal.

https://youtu.be/71RNBq-Cggs

And yes, I realise I was wearing my HANS, but it was not attached to the helmet... Doh!

Great day out, shame about the weather. seems we both miscalculated the gearing. You should gain a load of top end using the avon 13's if they will still go on.

Looking forward to Wiscombe.

I thought I’d do a capture of what I’ve changed on the car recently (the fun stuff, not the problematic carb stuff!), with before/after weights and the cost per kilo saving. In isolation, components tell one story, but the assemblies and associated losses vary quite a bit.

Now before you read further, please note the following:
Yes, it was an expensive vanity project just to tart up a few bits…
No, my wife does not know the true cost of the entire works, frankly until I kept note, neither did I.
I measured all weights stated, both new and old, hung from digital scales
Yes, I wish I hadn’t kept track. But I did, so you can now enjoy the collected knowledge…

Cheapest £/kg saving is the Battery. My Bosch (S3 017) was 12.8kg. Powerlite PS-12 with bracket weighs 1.7kg. 11.1kg saving at £17/kg.

Second most cost effective saving is Polycarbonate windows. I went for ACW 4mm full set, with XL locking sliders in both front windows. 7.1kg for the set, against the glass that was 4kg (rear), 2.82kg per Quarter (opening, less frame) and 4.35 per front. Total of 11.3kg saving. This doesn’t include the huge peripheral savings attached to going polycarb, but I’ll come to that. £21/kg.

Close third was Rear drums. Import minifins expertly machined by Shane were 1.2kg each against the 3.6kg of standard rears with spacer. 4.8kg saved. £25/kg.

Starts getting expensive beyond this point, but supporting mods for big changes were necessary. Changed from MG Metro Turbo vented brakes to 7.5 grooved with alloy 4 pots. Front brakes (discs, calipers, hoses, drive flanges, pads etc) saved just under 7.5kg but cost £50/kg.

The front brake changes allowed fitment of 10” wheels, which with tyres saved 9.5kg. The change came in at £90/kg, but a somewhat false representation, as I didn’t pay for the tyres.

Beyond this point the single component savings get extremely expensive, but are better grouped in the effective areas.

A selection of the most expensive savings as components; KAD radius arms, SC rear hubs, DSN rear brake backplates and Protech shocks came together to save 10.98kg, but at a pricey £106/kg. This was purely because I could, and some of the components I’d been collecting for nearly a year. But it did ultimately send me down the route of looking at most things when I switched to 10” wheels. I replaced the whole rear assemblies complete, as I have another project I will use the old ones on. To work on an entire assembly of new and very well made parts was a rare treat.

Interior parts were watered down by vast savings of “free” weight gain by removing stuff. I’d had an attempt with the doors previously (removing interior lock, handle, using 3D printed window winder and carbon doorcard – 3.8kg saving) but removing the glass, gave me a huge saving with the removal of winder mech and metalwork. An additional 7.5kg came out. This takes the total impact of polycarb windows to 18.8kg costing only £12/kg.

The rest of interior changes were mostly removal, except for driver seat change and new harness. Again, not entirely representative, as seat cost nothing, but 20.11kg out at cost of £8.5/kg.

Changing the roof saved 7kg over the previous metal, glass and frame. With additional 1.3 removed of headlining. £71/kg.

Previous bits and pieces I’d done (boot, bonnet, bumpers and some odds and sods) totalled 15.8kg saving, at £97/kg. The alternator recently fitted was an expensive replacement, more for space than weight, but provided 1.25kg saving at £183/kg.

Total since I was tracking (again, part of me wishes I hadn’t started, but it’s interesting data if nothing else) is 199.59kg came off the vehicle and 95.57kg went back on. 52% saving, that’s 104.02kg lighter. With the cost per kg of £47.71. That total number does help justify a few of the big ticket purchases, and makes you realise how many little things that can be adjusted/modified/changed/deleted for free, reducing the “spend” on the car.

I’ll not be selling it, and it’ll probably be a financial burden forever. I’ve spent more on it in the last year than the last 19 years combined. I'm fortunate that circumstances have allowed it and contracting some seriously strange volumes of work in the last year are made worthwhile, in my opinion, by doing the things that make me happy. At this point I’m mainly justifying it to myself having totalled up the numbers.

I’ll weigh the car after the show this week, and will no doubt be horrified by the vast heft of what’s left! Will report back with my findings.

Congratulations if you made it through that little lot!
Stu

£185/kg!? I had to read that bit twice!

Shane

Good morning people, I write to you today in very high spirits. A cracking weekend at Wiscombe Park, hosted by the Five Clubs. Foggy start to the days brightening up and drying the track out quickly meant there was a marvellous window of opportunity at the end of the mornings to have plenty of grip, and plenty of power.

Started Saturday with a decent practice run, slow launch with greasy start line but happy with a 51.72. I’d switched my fronts to the rear as despite the three events with the tyres on, the rears still had the knobbles and were not bedding in well. But the run had certainly helped get them somewhere handy. Messed about with the tyre pressures again, think I’ve got some numbers that work now.

First timed run was reasonably early and as I mentioned, still cool enough for the turbo to be very happy, track had dried out well too. I was hoping to get around my previous best of 49.62 from the National meeting 5 weeks ago, but it didn’t end up that way… I had a cracking launch and attacked the hill, felt very sloppy through the esses but it was a committed run. Got to the top to find I’d taken 1.25 seconds from my previous best and finally made it to the 48 club. 48.37.

Returned to the paddock and a competitor who’d followed me down the hill came and asked if I knew my car was crabbing. Had a look over the rear and had nearside toed in and offside toed out. A couple of the mini lads had mentioned having similar issues with new adjustable brackets, most seeming to get rid of the powder coating on the serrations. News to me, but not going to ignore the advice. Straightened the back end out and generally tried to calm myself down (Took quite a while).

Afternoon did not yield any improvement, not that I imagined it would to be fair, but it did provide good data and solve an issue that has been occasionally lurking. I’d been utilising the tyre warming area this event, only usually so on wet/muddy events to clean the tyres, not entirely sure of the “Warming” effect that a 3m strip can provide as you then get lined up and sit on the line for a while. I’d been using it to help bed the new tyres in, but it did seem to be helping the launch as I was spooling up under load and clearing the plugs up too. Second timed run I managed to better my launch, all going well till the straight climb to bunny’s leap, I’d reviewed the footage of the decent run and noticed I’d fudged the shift to third, so obviously put extra effort in. This resulted in missing it completely, for two attempts before finally finding it, costing a decent run.

Third timed run and I decided not to warm tyres, could not get off the start line. The launches had been 3.14 and 3.07 previously, but was 4.94 on this run. Just had nothing till it finally revved up and came to life. So the tyre warming area is good to clear that issue. Got the shift nailed that run anyway, and the rest of the run was clean, with a decent launch, theoretically could have been faster than my new PB and Class record of 48.37. Alas.

Sunday was a new day, the morning was even foggier and slightly cooler. Turbo weather. I’d joked in the paddock and suggested that now I had done a 48 run, I should be sub 50 in practice. Only went out and did it. Practice run 49.64. That’s 2 hundredths off my August class record. I was buzzing.

Tyres were coming into play and my faith in the brakes was all time high. Plugs were as good a colour as I’ve seen in the car. All coming together nicely.

First timed run. Bettered the launch again. 3.05. Nailed the shifts up to bunny’s leap. Linked the esses well, not too shabby on sawbench hairpin and made it to the top cleanly. The timing board up the top paddock had moved from the Saturday, and whilst staring around for it, noticed one of the other competitors pointing and waving at me. 47.43. I lost the plot. Celebrated like I’d won a world championship.

Managed to prove the run wasn’t a fluke in the afternoon, set a 47.60 with a faster first half split, but really messed up the entry to Sawbench, didn’t stay wide enough and had to climb over it scrubbing lots of time.

By the end of the afternoon it was very hot and the car was not too happy. But still kept the launch tight and split under 24 seconds. 48.90. It’s all to gain at the two hairpins and late braking for the gate, which is easier said than done. Particularly when someone belted into the tyre wall on the first day and the skid marks remain as a horrible eye drawing marker on your runs!

Car is smokier on start-up these days, and the plugs not happy from long idle time pre run, think the head will want new valve stem seals and a general overhaul this winter.

A great weekend, in great company. PB’s and class records being broken across the board. Finishing 4th in our club as fastest road legal car is a first for me. Another Wiscombe next Saturday, and two events at the end of the month make it a busy one, but all down to the wire for the various championships and challenge cups.

So here it is: New PB 47.43

https://youtu.be/IFcTQoyH-bE

Well done

Great effort, so pleased that your making some good headway with the car post teething problems.

Shane

Great weekend, took a huge chunk off your pb.

I certainly have a few things to look into!

Got my ticket for next weekend at Wiscombe, hope to see you there!