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Post by thruxton on Jul 1, 2017 12:38:48 GMT
Beautiful workmanship.
Superb build and well documented.
You should be justifiably very proud of your project, I love it!
Just some questions that I hope you will answer please?
So putting USA Hp aside, for REAL UK horsepower.
I was surprised to see the turbo finishing at the Rpm it does, is this a mapping preference, or did it fall off a cliff there?
I've trawled many a power graph of this turbo on the MX-5 engine and see it running hard to 7200 Rpm, with less power and torque.
Doing a lot of track time I like the 7200Rpm limit I set myself so I'm curious you see?
To clarify is your engine 1.6 or 1.8 ?
With the above and the "perceived wisdom" of forum sites, do you foresee gearbox problems and recurring diff problems?
If so have you yet put your minds to that or will you wait and see?
None of this is any form of criticism, what you built is beautiful and proof positive of your great abilities.
One reason I'm build my V6 is because I have been lead to believe that the gearbox and diff can't handle what you chaps have achieved.
If they can then maybe I should just copy you chaps.
No, I'm getting fit again and will carry on with my V6.
But honestly, well done I think what you have done is fantastic.
Regards.
Rich.
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Post by davefab on Jul 3, 2017 12:00:10 GMT
Hi Rich,
Thanks for you comments, we'll do our best to answer your questions.
The whole uk / us hp measurement issue is a bit of a can of worms that we did discuss on the day with Nick. He's assured us the figures we've quoted are UK horsepower measured at the wheels. Nick made a point of saying that if we'd run the same car in the US these our power and torque numbers would have been significantly higher.
The turbo now happily pulls all the way to the redline which we have set at 7200rpm. On the day we were suffering from a type of soft rev cut which we couldn't quite put our finger on. It was only a day or so later we found that one of the coil packs was bit loose and we think that this was causing the drop you can see on the graph. It would be interesting to put it back on the dyno and see if makes even more power now.
This is all on a 1997 mk1 1.8
You're right, there is a lot of 'perceived wisdom' out there, particulay online. We have spare gearboxes and diffs should there be a problem, but at this stage the drivetrain is performing well. It's first track outing (combe on the 22nd) will be the real test. We're fitting a torsen lsd this week which we think will make a big improvement to the car's ability to put the power down.
If the mx5 6 speed does turn out to not be up to the job we've read with interest that people have installed Tailgate McNoIndicate gearboxes and diffs. This would make for an interesting project but for the moment it's a bridge we'll cross when we come to it. In the meantime we'll use the best fluids we can find and try to drive with some mechanical sympathy.
Thanks again for your comments, looking forward to seeing your Jaguar conversion in the flesh.
All the best,
Dave.
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Post by thruxton on Jul 3, 2017 12:44:54 GMT
Hi Dave and thank you for the detailed reply I appreciate that.
I do not doubt your HP/torque figures for one moment.
They are the best I've seen, but what I was once aiming for with the MX-5 1.8 engine.
If you can hang the drive line together without "grenading" everything that would be definitive proof to go along with what you have already shown.
This is going to be interesting.
Waaaay back in the early 1990's I was involved with Paris Dakar racing Rover derived V8 engines.
Of course these er hem somehow found their way into our road cars.
Problem was the gearbox exploding in quite short order.
As a last ditch attempt at resolving the gearbox issue without spending huge sums and it being worth it for I am sure you understand integer-gear ratio mathematics,
I decided to creat an external bolt on cradle for the gearbox creating a vast amount of ridgity.
To my surprise no more exploding gearbox problems. The SD1 back axle could take anything we sent its way without issue.
I will be watching your reports here with great interest.
I hope that the resorting to a custom drive line will not be required and that an Engineering solution to the problems, if they indeed occur, will be found.
Regards.
Rich.
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Post by LewisEK on Jul 3, 2017 13:17:53 GMT
DAVES, I saw this at the 2B Retro show in Chelt, so much swag! Looks great IRL  |
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Post by thruxton on Aug 9, 2017 5:34:44 GMT
Hi Dave.
Thank you for the call yesterday, much appreciated.
A great exchange of information.
Will you please put up some pictures showing the intake tubing in situ on the car that would be very helpful.
Regards.
Rich.
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Post by scottydugg on Aug 9, 2017 11:27:27 GMT
Just spent some time reading this, looks like an epic machine and enjoyed all the in depth details re. manifold manufacture. Shame I missed out on the bottle opener! Once mine is through an MOT I'll be in touch for a few parts  |
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Crumpets
Chats A Bit
Insert witty remark here...
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Post by Crumpets on Aug 10, 2017 21:57:28 GMT
I'm sure i won't be the first to say how epic this build is:
The workmanship is second to none. - I look forward to seeing more.
- Crumpets.
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Post by davefab on Sept 20, 2017 7:51:53 GMT
Hi all, It's been a while since we did an update but lots has happened - with plenty in the pipeline too! We've made a large effort to drive the car as much as possible daily/weekend blasts and on track in the recent months. Starting from the beginning... We had an awesome time at 5Fest and really enjoyed meeting lots of you lot, the car performed really well all day and we even got to have a go on slicks (thanks Cupidstunt!)     After 5Fest we did a job that was on the list and changed the original slipfit joins we did on the exhaust system to V-Bands which made the whole system much more user friendly to work on. Following on from 5Fest we did a few days at Combe including this really wet one!   Massive thanks to Alex James Photography for those pictures - Super nice, mega talented guy, and MX5 mad too so if you have any photography needs he's the man! We spent much of the day learning the track and the car. The instructors were really helpful on the day and the car was a joy to drive - despite the 370bhp the car behaves very controllably. A real testament to modern turbocharger technology. Later that week we had some track time and a small trade stand booked for Forge Action Day which was a great day and despite our doubts the weather held up OK.  After a storming dry session in the morning our track escapades were brought to end by an unhappy 6 speed gearbox. Upon stripping it down we found a really unhappy 4th gear.  Gearbox solution coming soon! It was great to see Jackyboy on the day too, who was in full attack mode with one seat to commit to a one lap stormer - what a hero! Following the gearbox failure we stuck in a 5 speed we had to do the MX5 Show and Shine, it was a great event and very well organised by Martyn. We had a great time and look forward to the next one!  RotrexChris's car looked great on the day and won 2nd place for the NB Modified award, can't thank him enough for his support! In other news, we've purchased a Mk2.5 VVti car for development - but that might require a new thread. Our plans now are to retire the car for the winter and start phase two of the build. Chassis stiffening, gearbox solution and an improved intake are top of our list. Watch this space! Cheers, Dave(s) |
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Post by tgbshelby on Sept 21, 2017 17:51:48 GMT
FINALLY A MK 2.5 VVTI IM FINALLY GONNA HAVE SOME LOVEEEEEE
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Post by rich5660 on Sept 22, 2017 9:24:55 GMT
davefab I may be selling mine soon if you guys are after a vvt
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oli
Chats A Bit
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Post by oli on Sept 22, 2017 20:36:14 GMT
davefab I may be selling mine soon if you guys are after a vvt Nooooooooo!! |
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Post by davefab on Sept 29, 2017 20:45:11 GMT
Figured we'd do a quick update! The car is now floating in our new workshop ready for it's second phase, unintentionally the new unit is even called Unit D! Here it is looking really lonely on Monday..  A little less lonely..  A day later and it's up in the air for round two of the build!  Bumper off for the first time in a while ready for some changes.  We should also mention - this happened!  We still can't believe it but they did a full road test and have done a really comprehensive write up on the project. Well worth a look! We're going to have to frame it. We've got a few ideas regarding the gearbox, one we're thinking about a lot is a 7 speed DCT gearbox from an E90 M3 (Maybe we have been drinking too much coffee). The idea of a modern dual clutch box with all that power is really tempting - we're really keen for it! Any opinions would be welcomed! Dave |
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Post by tgbshelby on Sept 29, 2017 21:29:44 GMT
Figured we'd do a quick update! The car is now floating in our new workshop ready for it's second phase, unintentionally the new unit is even called Unit D! Here it is looking really lonely on Monday.. A little less lonely.. A day later and it's up in the air for round two of the build! Bumper off for the first time in a while ready for some changes. We should also mention - this happened! We still can't believe it but they did a full road test and have done a really comprehensive write up on the project. Well worth a look! We're going to have to frame it. We've got a few ideas regarding the gearbox, one we're thinking about a lot is a 7 speed DCT gearbox from an E90 M3 (Maybe we have been drinking too much coffee). The idea of a modern dual clutch box with all that power is really tempting - we're really keen for it! Any opinions would be welcomed! Dave I think I speak for all here when I say.... DO IT |
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Post by howardb66 on Sept 30, 2017 11:11:40 GMT
Hey congratulations on the new workshop & mag feature. The stuff you guys have/are producing is top notch.
Just my 1p worth, driving a MX5 is all about interaction & having had various permutations of self shifting gearboxes, I've found that after the novelty has worn off I just left it in 'D'. Think it'll be a very limited market considering people's budget. However as a technical 'tour de force' it'll be an interesting project.
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Post by atlex on Sept 30, 2017 12:47:34 GMT
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le sigh