vts cams without a map?

8th May 2009, 09:54

how long could i run 708 catcams without a map for? ive got the cams but cant afford a remap for around two months if i get the cams timed properly will this be okay or will it kill them over time is it best just to wait and get it all done at once? thanks

8th May 2009, 10:57

yes, but i am selling a remapped 3plug ecu, so buy that

8th May 2009, 11:09

3plug for a mk2 vts? how much mapped to what mods?

8th May 2009, 11:12

yes.

mapped by wayne @ chipwizards

708s
ported TB
GMC manifold
magnex exhaust and decat
BMC cda filter
made 152hp

£180 + your ecu

8th May 2009, 11:14

Quote:

Originally Posted by williamsvts

yes.

mapped by wayne @ chipwizards

708s
ported TB
GMC manifold
magnex exhaust and decat
BMC cda filter
made 152hp

£180 + your ecu

You got all the reciepts from the mapping?

If i can get my hands on a set of 708's ill defo buy that off ya

8th May 2009, 11:15

Quote:

Originally Posted by williamsvts

£180 + your ecu

Can't argue with that when Wayne charges around £450 for mapping!

8th May 2009, 11:16

Quote:

Originally Posted by Tom

You got all the reciepts from the mapping?

If i can get my hands on a set of 708's ill defo buy that off ya

no, i got it done about 3 year ago, just got the graph from him.

8th May 2009, 11:17

I have the same question really, but apart from buying Williams ECU, what dangers are associated with running an unmapped J4 engine with 708's/PH3 cams for a few thousand miles say?

8th May 2009, 11:18

none imo, ran mine for 6 months unmapped, few 1/4 mile days, couple track days.

8th May 2009, 11:22

Had my pt51 vts unmapped for over a year. Used more petrol than normal, was quicker than before the cams were fitted and it had a dodgy-ish idle, thats it

8th May 2009, 11:24

Quite a few people run 708's/ PH3's unmapped with good results. Not sure what the idle would be like to live with but I suppose you could always tweak the timing to improve it?

8th May 2009, 11:26

Quote:

Originally Posted by LeeumH

Quite a few people run 708's/ PH3's unmapped with good results. Not sure what the idle would be like to live with but I suppose you could always tweak the timing to improve it?

mine idled like standard.

8th May 2009, 11:31

Quote:

Originally Posted by williamsvts

mine idled like standard.

Maybe it's just when you use the standard timing marks they idle like turd? I take it you set yours up with the DTI?

8th May 2009, 11:31

willians this is very tempting how do you swap and ecu over just unplug and plug in or is it abit more complicated? can you do it? will the ecu run without cams in car so i can buy now and fit cams later (wudnt of thought so but worth asking)

8th May 2009, 11:31

Quote:

Originally Posted by williamsvts

none imo, ran mine for 6 months unmapped, few 1/4 mile days, couple track days.

that's cool. no running mega lean/rich, so it's just the ignition timings that need mapping for correctly I guess yar?

8th May 2009, 11:33

Quote:

Originally Posted by VtsTom

Had my pt51 vts unmapped for over a year. Used more petrol than normal, was quicker than before the cams were fitted and it had a dodgy-ish idle, thats it

USED MORE PETROL...?! aw smeg.

ok so makes it run a tad rich then by the sounds of thing.

8th May 2009, 11:34

Quote:

Originally Posted by adsayer

USED MORE PETROL...?! aw smeg.

ok so makes it run a tad rich then by the sounds of thing.

Mine was never dialed in 100% though, i was leaving that for the remap which i kept putting off

8th May 2009, 11:38

Quote:

Originally Posted by VtsTom

Mine was never dialed in 100% though, i was leaving that for the remap which i kept putting off

so you just lobbed them in and was like 'sod timing 'em'...?

8th May 2009, 11:40

Quote:

Originally Posted by adsayer

USED MORE PETROL...?! aw smeg.

ok so makes it run a tad rich then by the sounds of thing.

High lift cams are always gonna use more fuel though. I guess the ECU compensates to some extent by injecting more fuel.

If it was me, I'd fit them and have the cam timing adjusted so the lift at TDC for each cam is what Newman recommends - should run fine!

8th May 2009, 11:41

Quote:

Originally Posted by adsayer

so you just lobbed them in and was like 'sod timing 'em'...?

Timing was just set to standard marks, ran fine and thats all that i was worried about at the time.

8th May 2009, 11:43

I can't see how they should... but I'm a noob with this stuff...

8th May 2009, 11:49

My understanding is the longer the duration of the cam, the better the engine can draw in air and expel exhaust gasses. To increase the power of the engine you need more air and more fuel. So by improving the flow of air coming into the engine, the ECU compensates a little by dumping more fuel in.

8th May 2009, 11:52

Quote:

Originally Posted by LeeumH

My understanding is the longer the duration of the cam, the better the engine can draw in air and expel exhaust gasses. To increase the power of the engine you need more air and more fuel.

yep yep yep, I understand that but for the engine to inject more fuel, the ECU has to realise that more air is in the cylinder than before... without a remap I'm not sure how it would know this, except under light loads and moderate acceleration when the ECU is feedbacking from the Lambda and targeting AFR at 14.7

under full throttle, i can't see this happening.

8th May 2009, 11:56

MAP sensor will tell the ECU the vacuum in the inlet manifold is different. So because the engine draws in more air, the pressure in the inlet manifold is different than before, therefore more fuel is injected. Not sure about the lambda, maybe that 'fine tunes' the amount of fuel dumped in?

8th May 2009, 12:03

Quote:

Originally Posted by LeeumH

MAP sensor will tell the ECU the vacuum in the inlet manifold is different. So because the engine draws in more air, the pressure in the inlet manifold is different than before, therefore more fuel is injected. Not sure about the lambda, maybe that 'fine tunes' the amount of fuel dumped in?

fucking tard

ahhh well at least I'm learning!

cheers man!

EDIT: naaa the lambda is used to prevent the engine running too rich/lean in light loading conditions, it's more accurate at putting in the correct amount of fuel in for a certain amount of air. whereas running off the other sensors the ECU is really just 'guessing'

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8th May 2009, 12:09

Quote:

Originally Posted by adsayer

fucking tard

ahhh well at least I'm learning!

cheers man!

No worries dude. I hope what i've said is sort of right... that's my take on it anyway haha.

Have a read through the GMC technical section, there's a page there about cams.

8th May 2009, 12:42

Quote:

Originally Posted by farry1988

willians this is very tempting how do you swap and ecu over just unplug and plug in or is it abit more complicated? can you do it? will the ecu run without cams in car so i can buy now and fit cams later (wudnt of thought so but worth asking)

mine is running the standard engine now, sold my cams.

just unplug ecu's after we have unlocked them and swap.

8th May 2009, 17:25

i ran my vts cammed for 6 months with no problems at all