4722 replies to this topic

[Nev]

Went for about 30 mile test drive tonight. Initially I had to re-bleed the fronts as they were dangerously spongey just rolling out of the garage. The old "inverting the calipers" trick let a load of air out. After this the brakes were initially terrible for 5 miles, but after about 30 miles of stomping they are up to about 75% of the efficiency of my old setup. Hopefully with more bedding in time and burning off the brake fluid I rather flippantly let get on the pads I hope that they at least reach the same effectiveness of the old setup. Initial bite is poor, but higher speed braking seems better. The extra 9 KG or so over the front axle has really helped handling a LOT, steering turn in much more positive. Handling over bumps seems much the same. The extra weight over the front axel leads me to recommend people put bags od sand or pebbles into the their battery compartment as an experiment, you may be pleasantly surprised ! When I parked up the discs were still shiney and smooth, with time they will rough up I hope, or I might be tempted to rub them with coarse grit them to speed up the bedding in. Thankfully the machining we did was accurate, no extra wheel wobble or vibration. Tomorrow I will take the wheels off and double check all bolts, check for leaks and double check the brake pipes are not rubbing.

Edited by Nev, 20 May 2015 - 09:41 PM.

[Ormes]

Do they do RC6 for these calipers?

[Nev]

I'm not sure about RC6 material, but I expect more aggressive pads must be available. However, I am hoping to avoid metalised pads, as they make terrible dust and cost a fortune.

[FLD]

When I looked for the Z17's I could only find DS2500's.  There was nothing more 'interesting'.

[Nev]

Bad news.

 

I have offered up the lug mounted Brembo calipers that I'd previous bought to the rear of the car only to find they a poor candidates for an adapter. Basically there isn't enough thickness/gap between the upright lugs and the Brembos lugs. The lower tie rod nut also gets in the way, meaning the caliper can only be mounted at about 2 O'clock , rather than 3 O'clock. Overall it doesn't look likely.

 

I think I will have to sell the rear Brembo calipers, and maybe install the OEM front calipers onto the rear using the Elise Parts brackets.

Edited by Nev, 22 May 2015 - 01:05 PM.

[Nev]

I've done about 150 miles with the new front pads now and things are feeling better. Overall (seat of the pants feel) I'd say the setup is braking at about 80% of the efficiency of the old OEM caliper setup with RC6 pads. Really, I should get the "app" on my phone to measure my 70 to 0 deacceleration  to see how it compares to the old -1.4g I used to pull with the old setup.

 

Anyway, I've found somewhere that sells RC8 pads for the front Brembos, so I might get a set of those, these have a coefficient of friction of 0.6 which compares as follows:

 

RC6.. = 0.5

RC5+ = 0.4

Mintex 1144 = 0.4

 

 

Edited by Nev, 22 May 2015 - 02:51 PM.

[Nev]

I did a "nippy" dawn run down to the south coast last weekend with Simon (MrApex) in his car (followed by rock climbing all day on the cliffs). Great fun without much traffic on the road. On returning, I have noticed that the wrap on the lower point of my exhaust has been ripped off by the car bottoming out! I guess I had my coilover settings too soft, so have had to click them up a bit. I have now successfully replaced the melted T3 gasket and sheared T3 flange bolt (with much bother and 5 hours of work). I have replaced all 4 bolts with new ones as it appears that reusing old ones in such a harsh (hot) location isn't a good idea. Got my insurance renewal reminder today, £500 for a year - does that seem sensible?

Edited by Nev, 03 June 2015 - 09:07 AM.

[chris_uk]

I pay just over £300 for mine fully comp, all the extras apart from breakdown, even an agreed value of 18k

[Nev]

I pay just over £300 for mine fully comp, all the extras apart from breakdown, even an agreed value of 18k

Blimey, that's good value.

[Nev]

Went for a little drive with the fully sealed flanges. Sounds a lot quieter and also turbo spool and low RPM smoothness and pickup is a bit better

 

[Nev]

siztenboots, on 05 Jun 2015 - 08:53 AM, said: Would it be worth getting an analysis of your oil Nev, just to see if oil scraper rings are doing their job and check the bores and see what the rings are like. You put uprated main bearings in the build so it would nice to know how they are doing.  

 

 

I would like to, but finding somewhere is the problem. When I rang round I got crazy quotes or simple dis-interest from large scale commercial places. Overall the engine is making reasonable vacuum on coasting (18 inch/Hg at 3000 rpm coasting down a hill), this has improved from the initial build. I still get a good deal of blowby (compared to a factory engine) but for a highly strung race engine that has to cope with huge temperature variation on the pistons I think it's quite acceptable. The piston to bore gap is something like 80% more than OEM from memory, so if the engine is just being used to potter along the pistons + rings don't get to swell enough - this is when there is more blowby and occasionally after cruising at 70 say I can get a puff of smoke out of the back (though the stem seals might contribute to this when the engine is running under inlet manifold vacuum conditions). However, once you start booting it for 30+ seconds the pistons + rings get to swell to the intended operating size get hot enough to fill the bore, vacuum/compression increases on my gauges and the whole thing feels like controlling a non-stop bomb ! I use super cheapo 20w50 old skool mineral oil and just change it very often. It still smells of fuel and dilutes, but with 1000 mile intervals, the fur on the magnetic sump plug is pretty minimal. I adopted this policy when I found fully synth oil was glazing the bores and stopping the rings from bedding in.

 

Overall the engine really prefers being properly hammered at both high loads and high RPM, sitting in traffic and coasting around at low RPM simply doesn't do it any favours in my experience. My AFR at start up is about 12,  I think/guess this is main reason for the petrol getting into the oil as I think the rings will be less inclined to stop fuel seaping down the cylinder walls. The bearings are fine ATM, there is no glitter/gold/bronzy residue in the sump. I do worry about my big ends after I had one fail, hopefully that was a 1-off manufacturing issue or perhaps an oil starvation issue due to a blockage. The engine was flushed and cleaned after the big-end failure and a brand new rod put in obviously as well as a new crank (so all mating faces are new). I currently have limited RPM to 7500 to reduce the loading on the rods, and the new ECU map controls the torque like a wizard, so I think the compression stroke stress on the rods is far less now.

 

I almost always use the low torque map now, that only makes 340 ft/lb, so from a torque persepective the engine isn't any more stressed than a stage 4 VXT.  Very occasionally (if I feel threatened by something!) I flick the switch to make 425 ft/lb which must increase the stress on the thing. I think I've only done this about 4 times in 6 months.

Edited by Nev, 05 June 2015 - 08:59 AM.

[fezzasus]

Oil analysis isn't going to show anything useful. Certainly won't be able to tell you how individual parts of the engine are performing. You will get wear metal breakdown; iron, copper, tin, lead, aluminium. That's it. Without multiple measurements tracking oil with time, you won't see anything.

[vocky]

Nice feature in this months Performance Vauxhall mag (renamed Total Vauxhall mag) 

[Nev]

Nice feature in this months Performance Vauxhall mag (renamed Total Vauxhall mag) 

Did you buy that from a shop or did it get posted to you Neil? If the former I'll try and find a copy on the shelves tonight and see what they have to say. Ta.

Edited by Nev, 05 June 2015 - 02:10 PM.

[leevx2.2]

Yes nice feature clean you engine Nev ;-)

[Nev]

Ha ha, I'm proud of my dirty, smelly, oily, filthy engine bay. Just so long as it works well it is doing it's job, being pretty and blingy isn't it's job Did they show the picture of my gherkin/pickle jar swirl pot? I specifically told him that it (and the bird box) was the part of the car I was most proud of. In fact, since I fixed the T3 flange exhaust leak the cabin no longer smells of fumes and I miss not smelling of "manly hydro-carbon perfume" after a blast!

Edited by Nev, 05 June 2015 - 05:53 PM.

[smiley]

We need a scan of the article

[Nev]

Went for a dawn Welsh run with Hairy and Dumfunk today, with Josh as my VIP guest Let Josh have a drive on the twisties in Nipper so he could test the brakes out and see how he liked the power/ECU combo. I couldn't believe how fast he got to grips with it and within 5 miles I was wishing I'd put my rubber pants on, realising why owners don't like being a passenger in their own VX! He was of course very safe and controlled. When we got back, we discovered that my vacuum relief valve on my vac booster had unwound itself and was dumping most the engine generated vacuum to atmosphere(!), which explains (at least in part) why my brakes had been so bad. When we adjusted this, with proper vacuum they improved a good deal and we both think the pads haven't even bedded in yet, so I need to get out on a motorway and give them hell I think.

Edited by Nev, 06 June 2015 - 09:24 PM.

[mbes2]

Went for a dawn Welsh run with Hairy and Dumfunk today, with Josh as my VIP guest Let Josh have a drive on the twisties in Nipper so he could test the brakes out and see how he liked the power/ECU combo. I couldn't believe how fast he got to grips with it and within 5 miles I was wishing I'd put my rubber pants on, realising why owners don't like being a passenger in their own VX! He was of course very safe and controlled. When we got back, we discovered that my vacuum relief valve on my vac booster had unwound itself and was dumping most the engine generated vacuum to atmosphere(!), which explains (at least in part) why my brakes had been so bad. When we adjusted this, with proper vacuum they improved a good deal and we both think the pads haven't even bedded in yet, so I need to get out on a TRACK and give them hell I think.

[Nev]

Managed to find a copy of the mag, scanned it in here (red circled bits are my fave bits):