[Willem]

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!

 

[ThunderFox]

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!

 

[robd]

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?

 

[Willem]

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!!!

 

[robd]

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.

 

[Willem]

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....

 

[Willem]

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!!!

 

[Binney]

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?

 

[robd]

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:

 

[Willem]

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!!!

 

[AdamR]

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:

 

[Willem]

that would be great, i'm still wondering about where the best place to put the extinguisher is, and how to rig it up into the engine bay and cockpit, most kits only seem to come with 2 nozzles, which doesn't seem enough.

the world of ITB intake runner lengths is giving me a headache tho, 16 inches cannot be right, surely!? I'm gonna have trumpets coming out of the bonnet in that case!! (not allowed in the regulations) I'm also confused as to whether the length should be from the valve to the end of the velocity stack or somewhere else...

more coffee & more research required there! thats definitely gonna be the last mod! Lets get the new engine running first thats this weekend's project!!!

 

[AdamR]

that would be great, i'm still wondering about where the best place to put the extinguisher is, and how to rig it up into the engine bay and cockpit, most kits only seem to come with 2 nozzles, which doesn't seem enough.

Passenger footwell for the bottle, one nozzle into your lap, the other at the fuel rail (poking through the top of the firewall), and put the handle where the cigarette lighter used to be I'll get some pics!

 

[robd]

My understanding of runner lengths was it was from the back of the intake valve to the opening of the trumpets/stacks. I believe if you had a plenum with a cold feed or something this would also be factored into the total length, but I'm not 100% sure on that! I guess this could be one reason why most manifolds etc curl around the engine as a way of increasing length? I think a lot of it depends on the rpm of your engine vs the rpm value at peak torque! Personally I've never really spent much time reading up on it though as I can see my life disappearing before my eyes!! lol

One thought I've always had is, what would you notice more, the gain in moving your torque band to the 'correct' rpm vs the throttle response of shorter runners! Personally one of the things I loved so much about ITB's is the throttle response, obviously you'd still have that whatever your ITB set up was I'm sure, but the longer the runners surely the slower the throttle response?

I would imagine with our cars, even turning one into a race car, the potential gains may not be 'that' noticeable anyway possibly and I guess it depends if you want to chase every last bit of go go out of the car.

Either way your car will sound sexy with ITB's and make small furry animals run in fear!!! :lol:

 

[ThunderFox]

I'm tempted by the ways of the ITB... but it's hard power!

 

[robd]

I'd say try not to think of ITB's as power...think of them as cool sexy sounding throttle response! lol

With ITB's your car will feel quicker than the actual gains you've made as the throttle response is so good. :thumb-up:

 

[Jacksheps]

Bodys is just more racecar

 

[Willem]

Definitely because racecar!!! :driving:

We'll see how much power i can squeeze out, i know a good Jenvey setup can produce 140bhp+ at the wheels, i expect i might be able to get ~130bhp with the right setup. I really need that torque to be present after 5000rpm too, which is where i'm suffering with the current setup, according to the dyno graphs anyway...

I think i'm starting to come to the conclusion that the overall length of the ITBs will have marginal impact on the whole setup, simply because there is not that much to be gained in the first place. The devil on my shoulder is telling me that's exactly why i should try to squeeze every last horse out of the engine. He keeps making me look at Wossner forged pistons and lightweight conrods, and talking about overboring the cylinders by 1mm....... where does the madness end!>?>!>??!! Who said "hard" power?!?!?? More like bloody expensive power!!!! At least i have my Megasquirt now, i will wait to install that until after Pembrey in 2 weeks time!!!

Anyway, back to the present. I took the engine out of the car yesterday, stripped the head off and then ran it via the crank with an electric drill and a 21mm socket! You could hear the #4 cylinder knocking so badly! even at what was probably only 100rpm! This time i'm going to put the head on a block that i know runs without knocking, and although the pistons are a bit old, and i have no idea how old the rings are, at least it should run!!

Just need to wait for a new headgasket to arrive!! Damn it! why dont i have multiple of these things lying around!!!?!! Once thats in i just need to set the timing properly again as we should be off!!!

ON top of the engine i still have the following to do:

brake ducting to install

brakes need bleeding

de-powered steering rack to weld and install

passenger door to be de-skinned

new switch panel to fabricate(as i don't need window switches any more and its cracked)

chop the dash

chop the rear bumper

remove the last bit of excess weight from the boot lid

Once i've done Pembrey i will install the Megasquirt on the current engine config.

Then i will work on the ITB setup which needs:

velocity stacks

better manifold, will try to construct something out of 45' alloy pipes and see about machining flanges of some description.

Air intake on the driverside

Some kind of support bracket

and now for the remaining shopping list:

Safety Devices full Roll cage (already on order, due in 6-8 weeks)

weld on quick detach steering boss

new steering wheel, one that doesn't bend when you punch it....

wider wheels, I'm thinking 8J front 9J rear, but that may be a step too wide... might get some 25mm spacers before i commit, but i already got the arch extensions...

4-2-1 exhaust manifold

ACL race bearings - need to check whether i'm getting the crank reground before i get these

balanced crankshaft, if it needs to be re-ground i might as well

Lightened flywheel, dont know whether to get one of the ones from the classifieds here on Nutz or a proper racing one

Racing clutch to go with the new flywheel.

wossner 84mm 12:1 pistons (HA HA HA!)

ZRP conrods (as above)

Piper Cams (might as well go all in)

Valves & valve springs.....

Like i said, where does the madness end, i don't think the last 4 will ever happen, I mean, what would that gain on top of the ITB setup, like 20-40 BHP if i'm lucky and do it properly!?!? for what £2000 at least... will it make me competitive? should i just spend the £2000 on a different car?!!?! like a Mk2.5?! FFS!!!!

I'm going back into the garage!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :wallbash: :wallbash: :wallbash:

 

[ThunderFox]

Having a hard time believing that Jenveys alone (and an exhaust at least) will give you 130hp to the wheels.

If this is true, that's where I should be headed I believe

 

[Jacksheps]

Lap times are 80% driver skill i say, so dont bother chasing every penny.

Theres a thread on here about lap times at combe and me in a supercharged mx5 1.25.....proper drivers in 1.6 na.....1.19

So yea my £2000 under my bonnet could have been spent better in other places by the sound of it ha!

Your best off building a safe & reliable engine