Cosworth BOA + Mazda MX-5? (pics)

[godrikki]

so have i won yet

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[M-Tech Automotive]

well well well...

A late finish for us here tonight!

The car has a few 'gremlins' in the wiring/earthing...

Everything is relativly smooth (some noise) without the aux belt on (alternator..) but with it connected, all hell breaks loose with our RPM signal... after talking to the customer about the loom, we find out that the noise supressor on the coil pack has been removed (although generally we don't use one normally!), so wil be fitting one of those and also looking at the ground straps etc.

Anyway...

With a rough, light mapping (with this noise issue) we have seen 222.8BHP@Fly. Theres plenty more to go, have only roughly given it the fuyel ot power/run, and only using a basemap for iggy curve...

Paul's going to take it away and redo some of the wiring and hopefully solve these noise issues, then bring it back for its final mapping

Will keep you all posted, on what will be one BEAST of an MX-5!

Matt

[Glenn.]

Top work.

[Oranoco]

I'm liking that

[cossie4i_]

Sounds like it will crack 230bhp then

Steve

[snoopaloopa]

Have you got the guys number as i like that intake fanimold

[M-Tech Automotive]

Cheers guys, shame we cant carry on really, but it will be back

Another chap asked me about the inlet. I did speak to him about it but he said the hours involved making it, it would be rediculous!

I do use a chap to do our specialst frabrication work and he is top notch. I will ask him a rough quote on replicating that one. Maybe Omega V6 inlets on both sides? muahahaha!

Matt

[JohnnyB]

I could be on for a win. lol

[M-Tech Automotive]

oop...

change of plan guys...

Paul came down from Leeds today to have a look over it and decide what to do, and after considering his options, he's decided to leave the car with us to completely re-loom and then complete the mapping!

The bets are still wide open! Im revising my initial guess and going to be a bit bold here and say 240+ (fly) :P Oh, and to make this intesting, the person who gets it BANG on with their first guess from now on gets a power run and cuppa on me if they find themselves in westbury anytime soon!

Rolling road day tomorrow as well chaps, £30/car starts at 11... BA13 4JW...

Matt

[Glenn.]

Nice one why didi he choose a cossie V6 engine and not a jap engine.

[moorespeed]

sound like my little mx5 cossy has raised some eyebrows

[costina]

243 bhp for me then Matt

Paul

[moorespeed]

me again
238 english brake and 240 ft lbs of that other stuff . dont let me down matt or mummy gets it

[M-Tech Automotive]

lol ooh stickin to under 240 then?

[cossie4i_]

Don't raise the standard rev limit (6250rpm), the bottom ends die if you do.

Steve

[moorespeed]

i am being on the conservative side matt as you know i recon av had 250 out ot my other ones on ford ecu by doing little tweeks the first boa i worked with 12 years ago made 224 bhp and 224 ft lbs of other stuff and have found now to unleash some of the 310 bhp that they origionly were intended for but the engine in mx5 is on standard cam time you know the little mods i have done on that one matt just wanting to know what my plenum makes

[mark_24v_wiring]

Ok revised guess is 237bhp fly

[mark_24v_wiring]

Originally Posted by moorespeed

i am being on the conservative side matt as you know i recon av had 250 out ot my other ones on ford ecu by doing little tweeks the first boa i worked with 12 years ago made 224 bhp and 224 ft lbs of other stuff and have found now to unleash some of the 310 bhp that they origionly were intended for but the engine in mx5 is on standard cam time you know the little mods i have done on that one matt just wanting to know what my plenum makes

Little tweeks is interesting do tell

[moorespeed]

little tips .if useing original inlet chances are it will need a decoke due to the egr crap then totaly remove the egr . i personaly use grany air box with K.N filter but cut the tube off the ambiant side of the air box and make a pipe to do away with the box between air mass and throttle body . fit a fuel pres reg off a RS2000 . make both exhaust down pipes same length and then get them together early on same as grany 24V not like sierra 4X4 then theres the cam time and cyl head work

[M-Tech Automotive]

I'm scared...

Just working on top end...

220ft/lbs and 221bhp so far, thats limiting at 5,800.

It still wants to climb more, but the limit of 5,800 is holding it back. I'm no cosworth master, and I understand these engines don't like to rev, but what is a safe limit?

Matt

[M-Tech Automotive]

Bit more ignition tweaking and the following has happened.... The spit at the end is the soft cut limiter...

[ScORTED]

sorry to change topic, but there are mx5's out there running circa 400bhp with decent gearkits / diffs and plenty of 200+ turbo ones running standard ish running gear, all that weight in the front is going to upset a car that handles beautifully though ?

[M-Tech Automotive]

We just supplied and mapped the ECU Paul has been playing with the BOAs for years, and he had one so he thought he'd do something different I think lol

[cossie4i_]

Originally Posted by M-Tech Automotive

and I understand these engines don't like to rev, but what is a safe limit?

Matt

Standard Rev limit on the Ford ECU is 6250rpm

Steve

[M-Tech Automotive]

Would 6,5/ 6,800 do any harm?

Matt

[godrikki]

forgot all about this beauty still sticking to 235 ha ha

[JohnnyB]

don't go any higher than 6.5 mate

Anyway you will start getting valve bounce at above that.

[M-Tech Automotive]

Cheers, 6.5 it is
235 I think is our top power @ fly

[Jim Galbally]

i wouldnt expect it to make much power above 6ish as theyre a bit asthmatic no point taking it higher than 65.

im shocked thats making that much power, thats MENTAL for a standard engine, almost unbelievable.

what is going on with that inlet tho as at first looks it doesnt look like it makes sense.

[JohnnyB]

Voted, 234 bhp how good am I.

if you chuck some BOB cams you should be able to extract a bit more bhp at the top end.

Think you will be close if not on the 240bhp mark withBOB cams.

[M-Tech Automotive]

Well Paul wants me to take it all the way to 7k, so I'll see what happens in week, The Hp is still on the way up as the torque isnt falling away at a faster rate than the RPM climb hence I reckon it might break 240.... then again it might just break full stop....

[JohnnyB]

you will valve bounce at 7k and you will find the crank will start to try and come out.

you will know when you have fucked it as it will sound like the main bearings have gone.

I have seen a Mk 3 escort RWD rally car try and hold it on 7k on the rollers with TB and the works.

you may just get what he did fucked mains, the block starts to twist and does the bearings.

or like 2 twin turbo ones cracked round the main caps.

well it's his risk.

http://cgi.ebay.co.uk/Genuine-FBE-St...d=p3286.c0.m14

thats what you need, with the high comp pistons and uprated valve springs and FBE dry sump.

The FBE crank is shorter throw and the rods are longer to stop the crank twisting in the block.

The heads are brillaint they breath very very well so the power will climb, but the blocks are WANK!

[moorespeed]

Just some news for you doubting Thomas’s
The MX5 cosworth is going strong and used daily
it revs to 7000 daily no problem . the only problem was my choice of clutch supplier as the clutch threw the friction material off the flywheel side of the centre plate and when I took it back to TECHNI CRUTCH of blackpool I wish I had recorded the verbal crap they where coming out with such as the input shaft was not central to the bell housing/the nose bearing was u/s the flywheel needed skimming and get this one the crankshaft main bearing were worn so bad that the flywheel was moving about,
so I found a company just down the road to me in Leeds and they fell about laughing when I presented them with the bits . The pressure plate was a transit item not cosworth and when put on the testing rig was found to have very little clamping pressure and that the face of the pressure plate when depressed was flapping about
That’s why I had problems getting gears when stood and that the centre plate had paint under the friction material and the friction material had been drilled too deep for the locating rivets so not enough material under the rivet heads
so Mick at clutch and gearbox supplied me with a proper cossy cover and cossy centre plate with the Mazda splines and all brand new not recon for less than the jokers in blackpool now i can get gears when stood and due to the higher clamping force of the cossy pressure plate i have confidence when leaving the obligatory black lines so if any body thought of getting a clutch from techni crutch my advice is give them a wide birth

[pee vee]

do a search on here for techni clutch mate. lol utter wank, no other way to put it sadly.

[moorespeed]

Ah now you tell me
I couldn’t believe the crap that they where talking
Saying the input shaft wasn’t central to the bell housing. That took me hours to get central before pinning and then welding the ford V6 bell housing to the MX5 cog box. Then they said the nose bearing was u/s.
Not it is brand new. Then that the fly wheel needed skimming. Not so it is perfect
then get this one. That the crankshaft main bearings where so badly worn that the crankshaft and fly wheel where moving around.
If they had given me a new clutch I wouldn’t have fitted it
maybe they should try making chocolate fire guards

[cossie4i_]

What power did it make in the end ?

Steve

[Ginger Will]

Got any videos?

[Pob]

Originally Posted by Lambchop

i had to google BOA to find out what the hell it was

I only know because i remember seeing a 4x4 classic mini with this engine in. the engine looked massive in it

[dojj]

at 7k the heads consume/require more oil than can drain back to the bottom end and then up again, even with the bigger drain tubes
the block flexes along the mains so that makes things intresting as well, you can see how the blocks get more and more webbing as they progressed through he years so yuo may have got a last of the line spec block and have been lucky

mind you, the weight of the mx5 might mean that the engine isn't working as hard as it normally is so that may explain no problems

well done in any case

[Pin_cushion]

Guess... 243bhp.
P.s Did you have a light blue Sierra 24v with the Granada 5 studs for sale a while ago...?