what controls the VTEC

[MattG]

hi ,

i jokely said about using megasquirt to run a honda engine , as far as i know its not been done before.... there are two reasons for this :

1) controlling the VTEC
2) ignition .eg lack of dizzy

i have heard that the VTEC is just controlled by some sort of solinoid turning on at a certain RPM , is this true ? if so MegaSquirt can controll a VTEC.

any ideas on no 2 , can you fit a dizzy ???

thanks for any ideas

Matt

[Geehawk]

I was going to ask the very same thing re controlling the Vtec. I believe that it is just a on/off switch that cuts in at a set RPM. So if your Megasquits :) can do this then I suppose it could be used, with something else (an ignition only ECU?) controlling ignition.

Got to be easier to have it all in one box though....

Graham

[MattG]

yes it would be easyer in one box , but not all of us going the easy route :)

when Ultra MegaSquirt (UMS) comes allong that will do full dizzy less ignition.

i guess if i have been able to fit a dizzy on a eco-tec i can do it on a VTEC .

not saying will , but building an ECU for 100 quid is allot cheaper than a DTA ,

Matt

[MattG]

cheers darren , and yes your are right about the advance of a normally diizy , but what MS allows you to is controll the timing with MS , but you use the dizzy to controll which spark plug fires . you have to just lock the dizzy off to do this , some cars had locked dizzys anyway .. as this is how they worked for a time untill dizzy less systems came allong.

i know i can pay more money ... but i am looking at doing a VTEC next year and what to do it cheap ... if i can :) i have allot of parts for a another MS allredy so will only cost about 40 quid to make another ECU.

Matt

[MattG]

i WILL be keeping the vauxhall , but parents are moving up north next year , and my dad has a couple of mini's to get rid of , one of them a clubman , also allways wanted make a mini for the wife ....

there is another reason which will be more clearer in the future ...

but i guess it all depends on what engine i can find , do honda injection systems fit infront of the bualk head. ? or does it require cutting.

Matt

[MattG]

cheers darren , so try and go for a 1600 VTEC , and run the std ECU + loom etc..

Matt

[MattG]

what about this :

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=2440194295

[PaulAmes]

Looks Ok, but it has done 116,000 miles. As long as the price doesnt go much higher. Try to get the mounts, CV joints etc. Costs to get them seperatly I have found!

[MattG]

thanks guys , on that ebay picture it actually looks like a dizzy on the end of the head ? or is it just a coil pack ??

thanks

Matt

[MattG]

cool , so just to re - ask again , some VTEC's do have a dizzy driven of the end of the cam.

thanks for all the advice.

Matt

[MattG]

cool so my cheap megasquirt will do then ..thats very good news.

Matt

[VTEC]

Carbs don't work very well with VTECs because you need to be able to change the fuelling at whatever RPM the VTEC switches on...... that is why the SAE one was low on power, it was basically running with the VTEC operation turned off.

You can run a switch to the VTEC no problem, this is useful in situations where there is a big lack of traction, ie in the snow, or heavy rain. But when you turn off the switch the fuelling is still set for VTEC operation, so you will be running rich, so its not a good idea to leave it switched off all the time. I often use my switch at this time of the year.

The VTEC can be operated via the DTA system which can be set to operate at any RPM, mine comes on at 4000.

Incidentally, if you ever do a track day they often measure your cars decibel output at 4500 rpm or more, like the Miniworld track day at Castle Combe, so being able to switch off the VTEC means the car is a LOT quieter, just remember to turn it back on again once you get on the track (unlike me!!!!!!!!!!). Also, make sure the scrutineers don't know about it.....

[DaveCoxon]

In CCC (walkers workshop) a few months back, they had a Vtec up for mapping. They played with the Vtec firing point, and (i'm struggling to remember EXACTLY what was written!!!) they played about with the VTEC point. They discovered that even at very low RPM, the engine made bags more power with the VTEC activated, than on the 'soft' setting...

Of course, tickover emmissions might be effected, aswell as Cam / follower wear if activated at tickover, but Walker did comment that it seems to be a little bit of a 'gimmick' - i assume by this he means why not activate it at a much lower rpm than the 4K everyone seems to set it to...

Has anyone with a Vtec tried it for themselves - i.e. setting it to come on much lower?

D

[andy@amt]

WE can map the std ecu so why dta.

[VTEC]

The graph results from my rolling road sessions show a massive increase in torque and BHP when the VTEC kicks in at 4000 rpm, i haven't tried it any lower than that.....

And your right about the fuel usage, mine doubles as soon as the VTEC comes on, which is at about 70mph in 5th.......

And 10 laps of Castle Combe used up nearly a full tank!!!! I worked it out as being 4 mpg!!!!!! Ouch.....

[BassAddict]

4 mpg ?!!!!! Chuffin' 'eck lad ! And there was me thinking the mini would still be more economical than the nasty renault I usually drive !
Have you got a rev counter yet VTec ?!
Maybe a manual switch for the VTec, in addition to the DTA control would be handy - could set it never to operate the VTec in the interests of economy whilst just driving around town !
Think I'll try playing around with the switch point for track days - might be worth lowering quite a bit, say to 2500 rpm, just so you know its always on. Might have to try a few runs/laps and different settings when its up and running !
Rich

[VTEC]

I have got a seperate switch for the VTEC, but this doesn't stop the DTA from pumping a massive amount of fuel in. You would need to have 2 different programs to be able to do that. Not an expert on DTAs so don't know if that is possible.

I suppose you could fit 2 DTAs back to back and have 2 seperate programs running, that you can switch between....

[BassAddict]

Hmm - trying to work out if its poss - I was forgetting about the fuelling change ! I guess if you drive around with a laptop on the passenger seat you're ok cos you can just change the switchover - but how you make a simple switch on the vtec solenoid also instruct the DTA to change maps - hmmm !! Time for some head scratching and manual reading !!
Rich

[DaveCoxon]

P8 pro might have a function to up the fuelling on the base map by a certain percentage with an external trigger, but this would then knock up the fuel everywhere -so after 4K, when the Vtec kicks in and the map has extra fuel anyway, it'd put even more fuel in there..

[MattG]

there is a version of megasquirt that has a VE dual table, so it switches fuel depending on a switch.

there are a few catches ... that version does not support ignition.

Matt

[andy@amt]

Some one can not map 4mpg.

[Colin.ab]

My engine is apart from the exhaust manifold completely standard; the intake is exactly as it came with the engine.

I had no choice but to use the Ford coil pack, as my distributor was completely melted when the original car was toasted. – Along with the injectors, all the wires and everything else that could melt, My heart sank when I first saw it on a pallet, but when Geoff had thrown away 90 % of the stuff on it, and Steve performed miracles with the DTA system, my initial concerns were all blown away the first time I drove it properly set up– “Mechanical Orgasm”, as he called it

I read with interest about the MS system, I wonder how you are going to map it all up? As even the DTA system took 4 ½ hrs to program on the RR.

But with at 200bhp at the wheels and 133mph on the RR I’m still grinning

My type R was complete and only £1500 + vat Inc delivery from Cheshire to Milton Keynes and I had the Rad, bits of the burnt loom and drive shafts too

The DTA is well worth the money, if I'd had the choice, I would have not used the Honda one anyway, as its too much arsing around to install it all. – You may as well just drive a Honda car if all the parts of the car are transferred with out improving the initial set up

I did have special leads made though, with the Honda plug, and the Ford Coil ends - speak to Geoff, as he can now get them made Their not cheap mind, but they make all the difference, as the plug leads don’t arc in the coil due to wrong connections

Colin.ab

[MattG]

the MS is no hard to tune then any other ECU unit , give it a try :)

Matt
(who is very druckn)

[Colin.ab]

Darren,

Ask Geoff about the leads or speak to Duncan at Tokyo Express

I paid £110 for them, but Geoff can do the same cheaper, but you'll find they'll still be in the £80+ mark

Not as bad as £246 for an MGF rack!

All the same, could have done without these “little extras”

Geoff can now also supply the Super Sprint Stainless Steel 4-2-1 manifold as on my car - makes a 8BHP difference over the standard manifold, and the noise is priceless !

C.ab

[mikeb]

how much for the 4-2-1 manifold ?

[Colin.ab]

Hi Mike,

I paid about £225 but Geoff can now supply it slightly cheaper

Have a look here

http://www.supersprint.com

C.ab

http://www.supersprint.com/prodotti/923101.jpghttp://www.supersprint.com/grafici/92int2.jpg

Standard: OEM
Claimed data:
Horsepower 190.0 Hp at 7900 rev/min
Torque 178 Nm at 7300 rev/min
Actual data:
Horsepower 190.4 Hp at 7710 rev/min
Torque 177 Nm at 6240 rev/min

Supersprint
- Manifold 923101
- No Kat. 923302
- Rear exhaust 922864
Actual data:
Horsepower 198.6 Hp at 7940 rev/min
Torque 187.6 Nm at 6390 rev/min

[mikeb]

thanks collin will put it on my christmas list :)