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Post by noobie on Apr 15, 2019 14:52:08 GMT
I think a K20 swap ends up just as expensive as a Rocketeer one for less power. A K24 could be built to be similar power, but we don't really have a good base to work from in Europe..so no junkyard swaps and more expensive still. I think both Honda engines are heavier than a B-series engine = lower power density than the Jag swap. Might make sense for a 400whp turbo engine, but imho not a 250whp one...not in Europe at least.
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Post by thruxton on Apr 15, 2019 15:13:09 GMT
Ok, if we're talking MK1 or 2 cars then I don't think you can beat the original 1.8 unit in turbo form. And some are making great strides with the n/a as well.
The gearbox "problem" has been solved by DaveFab, cooling, as I suspected and spoke to them about a long time ago. I had the same problem with the early development of the Rover 3500cc power unit in the SDI Rover. Solved it with an external girdle and cooling. That was back in the late 1980's when I worked with JE Motors and Rovertec engines.
The cost of engine swaps just does not add up as it where. ...... UNLESS it's for your own pleasure then price is irelavent. The 1.8 with an EFR Borg Warner turbo is mighty indeed. And the leap to the EFR is so rewarding over all other turbo units. It spools faster and holds longer than any others that I've seen the RR results of and the figures are waaaaaaaay more power than the MK1 or 2 needs.
Now moving onto the MK3 2.0. Well, Skuzzle do a fantastic 200Bhp + package and any of you who have watched .....
Watch Koenigsegg’s test driver lap the Nürburgring in a Mazda MX-5 .....
Now know that you only need 200 Bhp and be ...... ABLE TO DRIVE! You just can't go any faster..... so more power is not required.
Regards. Rich.
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Post by thruxton on Apr 15, 2019 15:39:46 GMT
Sorry forgot. The clutch/flywheel solution. Got to rack my brain here. So it's the rare Ford Mondeo ST200 flywheel. It bolts straight up to the Jaguar V6 crankshaft. The clutch unit I got made by a company in the West Country. Had an MX-5 centre and the Jaguar friction material size. Only cost about £160. The cover plate was I think, without finding my notes, a standard Jaguar unit rated at power + 20% and your moving a lighter mass. The starter was a Honda unit, I think, it need to be a high powered small unit and mounted as Clair's V6 Mazda swap engine to get the dog gear and rotation right. Need to look at notes for the exact one. The inlet manifold was also a rare Ford ST200, this was shaping up better than the others in the end. No, hold on, something not right there, to do with inlet tracks sizes. Ah, no that's it. It's was the ST200, but by a bit of swapping about using maybe the Mondeo 220 manifold the parts all matted to the Jaguar engine block inlet shapes. You see the Jaguar block is a different shape to the ST200 inlet manifold outlet but the two are interfaced by a lower inlet manifold that transitions form round hole to oval hols, yes that was it.
So..... Ford ST200 inlet manifold. Ford ST220 lower inlet manifold. Jaguar engine block.
Now that's about all the custom stuff required. Then it was good old fabrication work.
The sump was a bit "trixy". But I did manage to get an alloy Ford one to fit. Probably a modified ST or Mondeo one.. To make that a lot easier would have meant cutting the cross memeber, too complicated to explain here, but a suitably modified cross memeber would have made that an easy job. Or buy one of Clair's sub frames, but my idea was to keep it as cheap as I could. I think it was running out at about £2500 including the ecu, which was from Emerald Engineering, including a RR session. then you would need an engine for the main bits. But that did not include exhaust or engine mounts etc.
Regards. Rich.
Ps. ..... I do have bits for sale such as inlets and flywheels should anyone want them.
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Post by Zed. on Apr 15, 2019 17:33:25 GMT
The gearbox "problem" has been solved by DaveFab, cooling, as I suspected and spoke to them about a long time ago. I had the same problem with the early development of the Rover 3500cc power unit in the SDI Rover. Solved it with an external girdle and cooling. the davefab 'fix', was that their work? I saw something similar on MT.net a few years ago - chicken or egg? www.miataturbo.net/race-prep-75/manual-transmission-cooler-matter-diff-cooler-56151/post #6 ^^ dates back to 2011 also, is it an actual 'fix' or just a help? I've read lots of discussions about the (mx5's 6speed) shafts support / bearing positions allowing gear-mesh 'spread' that can strip gears? also the photographs showed gears that had witness-marking of mis-aligned gears. suppose an old roadcar gearbox that has wear is at a disadvantage when pushed towards its design limits if the mazda gearcasings are the issue, is there the market to have new mid-cases (for example?) made thicker / stronger? something that is common in the rally world (ford's 4 & 5 speed Escort 'Rocket' or Type E & Sierra Type 9 gearboxes have several aftermarket alloy gearcase options) obviously a ZF or Drenth replacement would be easier if somewhat more costly but Rover's LT77 gearbox has a layshaft driven oilpump & oilfed mainshaft gears, also on some models an oilcooler is fitted (possibly mostly on Rangerover & Discovery V8 models?), I rebuilt a spare for my '91 Discovery 200tdi a few years ago - no oilcooler fitted but the casting had the bosses un-machined. Rich.(slightly off-topic )
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Post by thruxton on Apr 15, 2019 18:15:11 GMT
To be more specific..... DaveFab have a kit of parts that seems from reports to have eliminated the gearbox problems associated with very high power being transmitted through the existing gearbox.
I hope this clears things up?
Regards. Rich.
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Post by noobie on Apr 15, 2019 18:21:53 GMT
Thanks for the info about the v6!
I don't think Davefab have quite solved the 6-speed problem yet. Has the cooler solution racked up a ton of track miles yet? Might be to early to tell.
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Post by thruxton on Apr 15, 2019 18:36:49 GMT
There is a thread on this forum that supplies a lot more information about it all. Just search for DaveFab and look at their posts, or, give them a call.
Regards. Rich.
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Post by Whistler on Apr 17, 2019 14:58:26 GMT
Dave Fab's thread hereDave fab have addressed the heat issue which is almost certainly a contributory factor, but I'm not convinced it's the only factor. I've blown 2 fairly low milage boxes with limited use on short runs - so I'm pretty certain excessive heat wasn't the cause (I don't run a temp sensor for my transmission which is the only way to know). For sustained hard use a cooler certainly can't hurt... 949 racing transmission & diff cooler solution below. Great thread though Truxton - always good to see owners doing different things.
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Post by Rickster on Apr 17, 2019 16:46:01 GMT
Ok, if we're talking MK1 or 2 cars then I don't think you can beat the original 1.8 unit in turbo form. And some are making great strides with the n/a as well. Yup, probably right, I think you could probably spend a lot less than a v6 conversion for more power BUT I dont think it gets away from the idea that a MX5 should be NA or at least behave as such and you are also right again - 200bhp is plenty enough but to do that NA with the 1.8 gets very expensive - there are a few HSA competitors that are running near that in their 5s but it aint cheap!! For me it is not just the power, its about having a go at something different and eeking a few more HPs, Having said all that I started looking at alternative cars but as I am on a "1 in 1 out" rule the 5 would have to go - which after going for a drive today with the roof down, I dont think I can do!! And as I am now signed up for MX5 challenge for the rest of the season, I might as well leave it alone until the autumn. An MX5 driven to its full potential is a pretty good track weapon in any case!!
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