Detonation?!?!?
Turbo Mini Forums

This is getting really frustrating now.

My headgasket went a couple of weeks ago. And I thought that it would be best toget to the root of the problem by firstly lightly skimming the head (to ensure a good surface), changing the gasket (BK450) the booking it in to get the timing checked and car set up on a rolling road.

I have got my car back and I'm a litlle disapointed, to say the least. It drives ok, but missfires all of the time.

What is the cause of this? Is it detonation? The guys at the rolling road said that the timing was correct and that the mixture (lamda readout) was spot on.

I think that i'll take it back to the m and let them know that i'm not happy with it. But do you guys have any suggestions?

In the 13's at last!.. Just

check out all those stock ignition parts first

have you got a lead wrong ?

does it get worse under boost ?

Edited by BENROSS on 29th Jan, 2007.

I don't think that it's a lead. I put tiewraps around the ends s that I couldn't mix them up.

If you give it full throttle from low revs it's normally ok. But if you are on part throttle and then give it a little more, that usually makes it miss.

It makes a noise when on full throttle sometimes. It sounds like very small pops, like missfires that dont make it out of the exhaust.

In the 13's at last!.. Just

Check the electronic ignition module on the side of the Dizzy! If you have one. Make sure the bolts are dead tight and if you can try a different one!

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

the majority of problems of missfire under boost is usually! caused by too lean a mixture, if the timing is spot on ....etc.....

having said that you can have it too rich as well, this causes a distinct fuel bogging and black smoke also with a loss of power

you are hearing it detting

the engines life is threatend

RULE:-.... if you hear a ping lift your foot!

this needs sorting PRONTO!

Or just listen to Benross as he knows way more than me lol.

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

story of my bloody life this!

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops

If the timiing and fueling is correct then its unlikly to be Det.

Det is not a misfire either - its the exact opposite!

Alex

AlexF

I like 1573wxs idea. dizzy module.

Firstly check the supply voltage. It's a common mistke to take the supply fron the 9V balsat coil supply.

Having said that, if the timing was ok on the RR then you'd have tohought that it was working then.

Still they do have a habbit of failing.

Wil

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

also check the coil this can be a headache especially if it the wrong one.

always looking for them bigger bunches of bannanas

You said "The guys at the rolling road said that the timing was correct".

Correct to what? If they have set it to the book then it may be too advanced.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

'T' piece trick?

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

might be worth a shot actually, will give it a try tonight. the anti run on pipe is currently blocked off with my 1/4" drive extension bar :$

I see your from essex, the only local bloke we let tune our cars is Ray at T&M colchester. Very knowledgeable and well worth a try.

-MINI CLUBMAN 1380 TURBO-

Thanks guys,

For the moment i have retarded the ignition. The guy at Thurstons (where it was tuned) said that the cause of the problem was the skimming of the head (increasing the C/R). Now I wish that I had given my head to Benross to get the chambers opened up before putting it back together!

What should I do, the performance is right down now.

In the 13's at last!.. Just

i would take it to another rolling road or try sorting it yourself.

the trouble with some rolling roads is that the operator knows N/A minis but not turbo minis. there is a big difference.

give ray a call at T&M electrics at colchester he wil sort it.

i run high CR for a turbo and havnt had any trouble since the teething trouble you usaly get

always looking for them bigger bunches of bannanas

the give away hear gents is...... the head gasket had blown once !
and now its detting again, even more so because the head has been skimmed in a mistaken attempt to cure the head gasket problem

which has blown because of det in the first place

below are some options

if your retard the ignition &................... too much!

this will give Excessive exhaust tail pipe heat, compounding det further :(

you have a few options

1/ run more octane

2/ lower the CR

3/ use less boost

4/ fit a good intercooler

/5 use all the combinations above ???..... (but i would not)

incedentley what CR and boost are you running ?
& have you an intercooler fitted

I agree with hoggy, bloody coils!

Benross,

I'm running the standard 7psi and 'standard' C/R (obviously this would be affected by the skim).

No intercooler as yet, it's still in the garage.

In the 13's at last!.. Just

there you go!

you will be back to square one, if you dont sort it

the head gasket on the A series is the weak link many other engines just melt the pistons

having said that, their the next to go!

Edited by BENROSS on 30th Jan, 2007.

But we don't know its Detonating yet!

Its misfiring - thats not det.

Alex

AlexF

I'm pretty sure that it is detonating. It makes a pinging sound when on boost that you can feel through the car.

One thing that i thik is being overlooked is...

Shouldn't this problem have been rectified during the RR session?

In the 13's at last!.. Just

I'd hope they would either fix it or tell you that something needed changing before they could continue!!!

Every day is a school day ...........

How fast and how expensive ...... the same question...