My bi-annual update will follow shortly...

Planning to compete in Sprints & Hillclimbs this year so had to make some changes:

New Safety Devices roll bar

New full size Cobra bucket seat - this took so much modding to fit!

New 6 point Schroth harness

Car is almost ready for the first sprint at Castle Combe on the 21st March!

Especially after this happened last month:

I've fixed most of it and I was on track again last Saturday! She's just not very pretty from behind...

 

Gutted on the crash and the bonnet mate but glad you fixed it. What's the rear like now then? Can't beat a few battle scars ey! lol

 

HA! the bonnet's a crumpled mess, but i dont want to rob the spare one off my other car just yet. On the back its the nearside rear panel thats trashed, but i've managed to knock most of it out, its a bit like a golf ball though!!! will take a pic when i get it out of the garage again!! Other than that the marks from the tyre wall are still on the boot lid, but it's still straight and it ran like a dream on Saturday at Castle Combe!!

 

Ouch

From what I've seen in the video, it could've gone wrong very fast. You were lucky! Hope the car is not too damaged!

 

Unlucky about the armco incident, glad to hear that she is nearly all straightened out now.

Very interested to see the new roll bar and seat etc in you next bi-annual update.

 

Just another thought.... presumably a good job you didn't remove the bumper metal work in search of that last bit of weight saving?

 

Right then, first some pics:

 

It go dyno'd last friday and after playing with the timing and advancing the intake cam a smidge we got 117.7bhp at the wheels. somewhere in the region of 140/145bhp at the flywheel depending on what loss you use.

Compared to when i first dyno'd it just after i bought it back in 2012, when it achieved only 96bhp at the wheels, thats a massive 22% gain!!

So i'm quite pleased with the limited engine work I've done so far which is:

• Ex-intake cam swap
• added vernier pulleys
• intake and exhaust port polish (rough)
• cleaned all valves & re-ground
• cleaned pistons & cylinders
• new rings & bearings
• rebuilt with new seals

Other work completed in the engine bay:

• coolant reroute - final pics of finished install to follow eventually
• new radiator
• power steering delete - currently running a non PAS rack, but a PAS de-powered rack is on the to-do list below
• aircon delete
• headlight delete including various brackets and cabling - pics to follow...

I'm currently working on a cold air feed from the passenger side sidelight, its a bit of a faff, but with some thing aluminium sheet to hand i think i'm going to end up with something rather clever. ing a 76mm feed from a 50mm gap is the problem, even with the headlights and associated brackets deleted!

Finally around the rest of the car:

• added P5 frame rails
• lots of lightening, including removing excess metal from bonnet and boot lid, front & rear bumper plastics
• removed all the windows and associated gubbins
• chopped the driver door interior and replaced with 1.5mm aluminium skin, see pics above - passenger door will get the same treatment eventually, might remember to take more pics when i do that as the skin is riveted in place, so no way to look inside!
• added awesome dash, of course i did this before removing the windows and the window switch is now superfluous!
• Installed the biggest seat an MX5 has ever seen, the very comfortable COBRA Evolution Pro-Fit. This involved creating bespoke seat mounting points so i could fit the homologated mounting brackets, lots of fabricating and welding later it's pretty good, if i do say so myself. below is a lovely pic to show more detail.
• Added Schroth Profi-II 6 point harness, another faff with the small amount of space left to actually put the mounting points, but its all in to MSA approved standards!!!

I think thats enough for now, will update with the results from the cold air feed, that should give a bit more power as we could actually see the effect when we were on the dyno as the engine heated up. The tiny vent on the headlight lid is utterly useless!!!

W.

 

Nice mate! Regarding the seats; I can imagine you needed to mod the car so the "ears" would fit, did the rest of the seat give any issues?

 

actually the "ears" were the least of the problem!! however bare in mind i do not have a roof or windows!!

To get the seat low enough to be able to use the original seat belt mounting points for the harness i had to chop out some of the steelwork in the floor, and flatten the whole area (read bash with a mallet).

I'd already chopped out the original humps to mount my previous seats. but there was very little space to fit the seat bases which were almost as wide as the floor itself. More bashing wityh a mallet was required to "move" the outside sill outwards more!!

I then welded in steels adding a bit of backwards rake to the seat and to provide a good solid base for the COBRA mounts to fit!

I'm really happy with the result.

 

Cheers for the explanation, I'm looking at a Cobra Suzuka to fit in my car so was wondering how much modification it would need in order to fit! I'll prepare myself and my tools for some metal work then

 

Looking good mate and sounds like you've been a busy boy. You got any close up pics of your dash panel and the ally door panel?

 

Did the first sprint in it at Castle Combe on the 21st March, Did great, well, at least i beat all the other MX5s there by 3+ seconds!!

Did notice the clutch going quite badly especially changing into third gear. Also had issues selecting third on previous outings, so was unsurprised to find the engine mounts shagged beyond recognition.

As i was is the US on holiday anyway i took the opportunity to get some engine mounts from good-win-racing.com and brought them back with me!!!

Will take a couple of pics once the engine is back in and running, just need to fill and bleed the radiator and then i'm ready for Gurston Down Hillclimb on Saturday!!!!

W.

 

Those engine mounts look the kiddy! Ive got the stiffened i.l motorsport engine mounts in mine aswell as uprated in the diff and it makes a great difference to the feel of the drive if you ask me

 

the engine is rock solid now, doesn't move side to side at all, even on full throttle from idle there is barely any rotation!!

diff mounts are on the list, but i couldn't get the PFR collar bolt out when trying to drop the gearbox, so dropping the diff is a no no at the moment. And i tried everything to get the PFR off, half a can of plus gas, pry bars, even got my blow torch on it, NADA! very frustrating! May have to concede and take it to a garage to have them have a go on a lift, rather than me struggling on my back!

 

I've got IL reinforced ones up front and poly bushings on the diff and it does make a huge difference

Could do without the diff ones though!

 

What about some diff void fillers instead, I remember when I fitted them to mine it definitely made a difference, plus you can leave the diff attached to the PPF etc too, just support it as you lower it down so you wouldn't need to mess with the gearbox! Would that be an option?

 

So, this happened one week before a double header sprint & hill climb at Llandow and Llys y Fran:

that's the big end bearing on conrod #4, diagnosis looks like oil starvation. may have run a little low and possibly some blockage in the block somewhere prevented oil getting to the #4 cylinder. BOO!!!

I tried to rebuild the engine after the failure happened at Llandow on a track day, spent the whole bank holiday on it, got it back together again running ok-ish, but using it at a test session at Llandow on the Friday before the sprint it was still knocking. I think the crankshaft might be damaged as i swopped the bearings and conrod for a good set, that said that may have been a rookie mistake, committed through desperation and ignorance. I'm sure its pretty ridiculous and naive to assume you can just swap in used bearings from a different engine and expect it to run fine!!!!

ANYWAY, now i'm transplanting the whole engine out of my spare car and that will have to do for the Pembrey! No time for tuning in the mean time, just timing advance possible for that. which sucks!

BUT i will now have the components to completely rebuild the old engine to a race engine standard, so that's the plan!!!

I also bought these:

Now i am slightly concerned that they seem to be mounted back to front... also the spacing is a little out compared to the manifold, furthermore the use of the silicone hoses means there are a lot of turbulent areas being created in the inlets, so i'm not 100% convinced they will stay in this configuration for long!

view from the manifold:

View of the "inlet" side in current configuration, pretty sure that the manifold side of the ITBs...:

In order to control all this I have ordered a Megasquirt from Phil at ExtraEFI.co.uk, so far his support has been excellent in answering my questions!

Now before anyone asks "Why not just ho FI?" thats because "actual real racecar" !!! if you strap on a turbo the regulations turn a 1800 into a 2.5l and suddenly i'm up against all sorts of uberpower Imprezzas and other such craziness. Sticking with NA means i'm in the 1400 to 2l class and will not be left for dust by cars producing 200+ bhp as standard, let alone in race trim.

I alluded to racecar, and i'm serious now, i'm doing a few hillclimbs and sprints, but i just found out about a race series at Pembrey, the Welsh Sports and Saloon Car Championship. This is open basically to anything with 4 wheels and the mx5 looks like a great car to enter, other cars in its class will be Civics, 3 series, Puntos, Fiestas and all sorts! Having seen the results from last season, my car is pretty much middle of the pack based on the results and my times last time i was out at Pembrey, so encouraging at least!!

Hillclimbs and sprints just arent doing it for me in terms of bang for buck and competitiveness. 4 timed runs, even at Castle Combe amounts to a total track time of around 600 seconds!!! Hillclimbs are 40s~50s per run i.e. sweet fuck all! Lots of waiting around and driving with cold tyres, all to compete in a class where the competition is driving fibreglass bodied space frame cars that only resemble the original car in their shape and their engine block and pretty much nothing else! I would have to spend £1000s to get the 5 to run anywhere near the times they are doing, so for that reason i'm out!

So what does this mean for the car? Well the shopping list has grown again:

Full Safety Devices Roll Cage with Door Bars (already have the back section installed as i planned to do this upgrade eventually)

Plumbed in 2.25l fire extinguisher - just figuring out how this will work!

Some new list 1A tyres, probably Yokohama AD08s or Continental ContiSport Contact 3s as thats the requirement in the class i'm entering.

Oh yeah and i need to book my ARDS test!

I'm aiming to complete all this to enter the race at Pembrey on the 15th and 16th of August! should be doable!!!

 

Those ITB's are the correct way around, look at the injector holes(or what they were originally), if they were the other way the injectors would be squirting into the filter and not the engine.

Those bodies you've got normally have a bolt on filter box which is why they look like that on the filter side. That silicone hose cutting could do with some tlc! As you've got a proper mani, I'd be tempted to get a flange welded on and see if you can ditch the silicone completely. :thumb-up:

Sounds like you've got your work cut out but sounds fun. If you need any help tuning the MS when it comes feel free to give me a shout.

Forgot to say, on the spacing, you'll struggle with that a bit as they're paired bodies, so you can't space them individually. If you do opt for ditching the silicone and getting a flange welded on, perhaps have a short section of pipe too matched to the spacing of the bodies.

 

Forgot two updates to the car:

Installed BC Racing Coilovers! Completely forgot to take a pic before i installed them! Have absolutely no idea how they feel as i've had a sum total of 9 laps of Llandow on them so far, and 7 of those were in the wet!!!

Installed the Superbushes Diff Void fillers, ran them for a total of 9 laps too....

 

Those ITB's are the correct way around, look at the injector holes(or what they were originally), if they were the other way the injectors would be squirting into the filter and not the engine.

Those bodies you've got normally have a bolt on filter box which is why they look like that on the filter side. That silicone hose cutting could do with some tlc! As you've got a proper mani, I'd be tempted to get a flange welded on and see if you can ditch the silicone completely. :thumb-up:

Sounds like you've got your work cut out but sounds fun. If you need any help tuning the MS when it comes feel free to give me a shout.

Forgot to say, on the spacing, you'll struggle with that a bit as they're paired bodies, so you can't space them individually. If you do opt for ditching the silicone and getting a flange welded on, perhaps have a short section of pipe too matched to the spacing of the bodies.

I know those Hoses are pretty ugly!! I have no idea what's up with the red shite on the ends, i'm guessing trying to seal the leaks!

I'm probably going to get some 135' bends and weld them on to the mani and then some type of flange like you mention to get the spacing right and so I don't get too much interference from the brake master cylinder. Its a bit of a project and i might take my time and not put it on the car until after i've rebuilt and tuned the race engine on the current ram air intake setup!

I was hoping you'd offer your help on the tuning! I will probably need it!!

Cheers!!!

 

Installed BC Racing Coilovers!

I like the look of the BC Racing coilovers, I look forward to hearing how you get on with them.

Good luck with the engine build, it will be nice when it is done, are you planning much in the head/cam department?

 

lol yeah, from personal experience unless you get a completely flush and true fit with the silicone hoses, you'll normally always get leaks, hence the sealant! Obviously it's not helped by the spacing being off as the bodies will pull on the hoses. You'd be surprised how much they can move about too without any brackets holding them in place, so again another tick in the box if you used flanges. :thumb-up:

As you're building a race engine it would be worth putting some time and thought into the length of the mani/runners to get your optimum performance out of them. There's quite a few guides online as to how to work out length based on desired rpm etc, worth a look.

Yeah no worries on the tuning help, I always love a bit of tuning and do love the sound of ITB's! :thumb-up:

 

Installed BC Racing Coilovers!

I like the look of the BC Racing coilovers, I look forward to hearing how you get on with them.

Good luck with the engine build, it will be nice when it is done, are you planning much in the head/cam department?

After much deliberation i went with them over the others available simply because of extra adjustability on damping, and also on ride height and preload. Also they come with 8kg front and 6kg rear springs as standard, with the relatively cheap option to buy replacements to fine tune even further!

Engine wise i will need to have a look at my budget when it comes to it, I've got no idea how much proper flow matching would cost and i don't think the gains will be worth the investment really, the head looks like it was skimmed at some point in its life already, although only a tiny bit.I think i'm just going to go for reliability and see if maybe i can squeeze some more revs out. I was looking at boring out and getting bigger pistons and lighter rods, but that's £1000 just for parts, so starts getting very expensive, completely defeating the point of the car!!! Although, having driven a mate's Jenvey ITB car which revs to 7800 and goes like stink (140bhp at the wheels) i'm in two minds. His engine was a good £2500-£3000 though!!!

So probably just start with checking if the head can be skimmed just a little bit more, then rebuild with cleaned valves and cylinders like before and then add the ITBs and mapping hopefully with some good gains recorded!

Then maybe look at it again in the winter!!

But given that i've just rewritten this three time I clearly have not made up my mind yet!!! Got to focus on getting a working engine in the race car to start with!!!

 

Sounds like you have plenty on! If you need any tips with the fire extinguisher give me a shout, happy to grab some pics of mine and send em over :thumb-up: