k1200RS cam timing 180 degrees out?
Turbo Mini Forums

Hi guys,

Recently put my engine back together and used the TDC method to time the cams. ie set the lift to 2.4mm when cylinder 1 is at TDC, as per the SC guide (and both cam lobes pointing towards each other). The car starts and runs but has no power after 3,000RPM and does not rev freely.

Suspect that the SC Typhooon ecu is 180 deg out from the cams. The waste spark ignition sorts itself out but I think the fuel is out of synch. Struggling to understand how the ecu knows when the engine is on a power stroke too? This should be an ecu configuration issue but it looks as if I will have to turn the cams by 180 deg and see if that solves the issue...

If this is the case, im still unclear how to time the cams properly given that they can be "correct" at 2 positions when set to TDC, given the 2:1 ratio with the crank?!

Cheers,
Nick

what kind of cam sensor you using?

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

also if your theory is correct you could swap injector wiring to 1&4 and 2&3. to prove a point.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

2.4mm overlap doesnt sound right for the 16v RS cams, but it shouldn't make that much difference.

What TPS are you using?

What's the total ignition advance?

what sort of AFR do you see at the point it lacks power?



As for injection timing, it can cause issues, but overall it shouldn't be dramatic. From memory the SC ECU uses batch fire injection that injects all or pairs of injectors every 180 degrees but then thats how a lot of older injection systems worked, so like I said, shouldn't be much of an issue.

Only Vems can run full sequencial without cam sync, but then depending on the engine, can suffer noticable running differences since you either inject on the induction stroke, or on the combustion stroke depending on where the ECU syncs up with the crank trigger.

Check your firing order, the k head is different to the a series.

Firing order doesn't matter with wasted spark, same cylinders are paired.

Not running a cam sensor.

Tps is the standard bike one I think.

I havent been out in the car with the laptop connected yet, so not sure on advance. Wideband controller is currently in the post!!

I think you are right about the batch firing, so that it actually cant be 180 degrees out....

Thinking about it, it feels more like a limp mode or somthing that is kicking in at 3k rpm or when I try to floor it. Still no closer to a solution though and starting to run out of things to try!

Without a cam sensor it can't be truely sequential so I guess, as Colin says, just batch.

Crude, but a lot of early stuff was the same.

The real question is, have you had it running properly before ?

And did you have a wideband before (not quite sure what "it's in the post" means, did you have one and it's being sent back or did you never have one) ?

In another thread you asked about getting a controller without gauges or sensors so I'm guessing you haven't had one before, or maybe just a narowband one ?

If so how do you know the fuelling tables/map you are running are anywhere near correct ?

Lack of performance could simply be the VE tables (or whatever the Typhoon equivilant is) are simply wrong.

If you don't (yet) have a wideband, I wouldn't push it until you know what your AFRs are.

Or it may all end in tears.

Just my opinion.

EDIT - new para added.

Edited by Rod S on 13th Apr, 2014.

Schrödinger's cat - so which one am I ???

I'm guessing this is on the base maps from SC which should be close but safe.. as long as your base timing is correct.

I had a hell of a job with an 8v lump getting the timing right at idle, so double and tripple check this with a light,

also the cam setting was very wide, (1. somthing mm) and this really made the lump sluggish, we reset to what the BMX manual said and it was much livelier.

To give a bit of background. The car ran faultlessly for 2 seasons in N/A form. It was setup with the 2.4mm cam timing and an SC basemap, then was fine tuned on an RR where it gave 130BHP, which is in line with spec.

Over the winter, i've had everything in bits so that the pistons could be dished. I then put it all back together, fabricated a manifold and exhaust setup to take a gt1752 turbo.

I've tried both the old N/A custom map with 150cc injectors (boost pipe off) and the new turbo base map with 440cc and the symptoms are the same. It runs really well at idle and part throttle, but anything more than that or at 3,000rpm and it stutters / cuts power. It sort of feels like the soft cut rev limit so i'm thinking it must be an ignition timing thing or ECU failsafe cutting in for some reason. Going to speak with SC on Monday and see if they have any bright ideas.

The car never had a wideband before, but i've ordered one and will be fitting it as soon as it arrives.

Have you got a map sensor fitted?

yes, thats one of the only other changes from before. I've changed from a basic temp sensor to a combined MAP and temp sensor bolted to the plenum. The temp and pressure readings on the laptop seemed pretty accurate

TBH without a wideband you are flying blind.

The previous N/A basemap (tweaked by your RR operator) may have been fine N/A.

A "turbo" basemap is just a basemap.

Without the AFR readings you really don't know.

And without AFR the EMS can't even try to correct (assuming it has that facility which I'm sure it does).

Silly question but have you reset the ECU properly to accept boost ???

I'm not familiar with the Typhoon, you say you have used a "new turbo base map" but what do you actually see in the software on your laptop ?

Does the load table (are whatever it is in the Typhoon software) actually show plus 100% VE ?

Schrödinger's cat - so which one am I ???

http://www.jbperf.com/

Lets keep this on topic...

Schrödinger's cat - so which one am I ???

Bugs aside.

Depending one your individual ECU configureation, unless you have set up for Speed Density Blending I think you might run into problems having the MAP sensor in the plenum which is infront of your ITB's. It will not run right with Speed density alone, and it wont run right with Alpha N alone, so you need to be sure the ECU is configured for both and at what throttle postion the Speed Density takes over.

I might be flying blind from an AFR perspective, but ive been running the old map (verified AFR on the RR) and ecu config with the boost pipe disconnected. so its effectively NA with perhaps a bit more restriction on the exhaust side than it had before. Other changes are the compression is down slightly via the dished pistons and ive used a combined MAP and temp sensor instead of just temp. Other than that, its just been pulled to bits and put back together again, as far as i can tell...

Edited by Rod S on 13th Apr, 2014.

Schrödinger's cat - so which one am I ???

Yeah, thats what was trying to explain in the previous post. The turbo is making boost, but ive disconnected the pipe ruining from intercooler to plenum, so its just N/A on the intake side and i'm running the N/A map from last year. MAP and IAT values looked fine yeah

so, whipped the turbo and manifold off tonight and put the old exhaust manifold back on and it started well and revved very nicely!

That rules out cam timing issues and all the other things ive been going round chasing!

So, the increased restriction of the turbo setup and the drop in air flow seems to be the problem. I'm guessing its hugely over fuelling for the amount of available air but i wont know for sure until my wideband controller arrives.

Still not convinced that excessive fuel / poor mixture would have these kind of symptoms but i'll gladly be proven otherwise!