VTEC cutting out


T

timmiblc

Marvel Honda Racing
Joined
Mar 4, 2007
Messages
443
Now HERE is an interesting problem...

On hard right hand corners immediately following hard left handers (lie through esses) my B16b (with baffled sump) is dropping out of VTEC. When I go to accelerate out of the corner the car needs to pull a bit straight (or be through the apex of the corner and starting to straighten) before VTEC will kick in.

A couple of times VTEC engaged, then dropped off, then engaged again once the car was a little straighter

As said before, sump is baffled, oil slightly over filled (always ran it like this so don't start on this, its not what the question is about).

Cornering force is around 1G from what we worked out on the day.

Ideas?
 
cuttingout.jpg


That is the corner where it was doing it consistently so I went a bit slower :(

I have heard all kinds of fixes and or advice about what to do from going to a normal sump (at one end of the scale) and changing to a full dry sump system to completely eliminate the problem altogether but I don't want to use dry sump mainly because of the cost.

I can imagine it'll be pretty useful for endurance events though?

Thoughts and comments please, I need to get this problem fixed before I race next (March).
 
what type of baffled sump do you have?

does it have vertical blades in it and a downturned lip around the oil pick up point?
 
Sump looks like this:

Sump1.jpg


Pressed rounded) edges aren't as deep though.
 
Dunno man, but its causing me a lot of heartache.

Can't really race until its sorted unless oil pressure drops off and

BANG
 
timmiblc said:
sump looks like this:

sump1.jpg


pressed rounded) edges aren't as deep though.
Click to expand...


looks like a nice sump,, only problem i can see with these type sumps is whether the oil can get back down into the bottom chamber quick enough.........
 
That's what I've been told too.

Pretty sure its not oil pump or it would be cutting out on straights as well?

Trying really hard to avoid dry sump - any suggestions anyone?
 
Also if that is your actual sump if you piant the inside,

the paint comes off and will block the oil pick up that would be my first point to check,

happened on one of our audis once that another tuner supplied a sump for,
 
Vtec once never engaged in my vti untill just before the limiter on a straight road. but that was only a one off. have you tried your standard sump to see if it still duz it?
 
I haven't tried the OEM sump yet - a bit hard to road test in this car :lol:

I had the baffle plate anodised black, it was pretty much the only thing on the car I was a picky bastard about :D
 
How resistant is anodizing to oil? I suspect what others have said where it might be plugging up the pick-up in the sump.
 
I would have thought anodising would be ok, aren't AN oil line fittings anodised blue and red?

I'll whip the sump off later today and have a look, but vtec is only cutting out at the corner in the pic, wouldn't a blocked pickup be cutting out everywhere?
 
Can't say for sure, although I would like to think that the chances of it being electrical are slim.

I guess there is only one way to find out?

I hate wiring :(
 
you mean cuts in then dies again?
might be a dodgy conection on the solonoid?
does it do it in the same rpm all the time or is it intermitant?
 
i had this with a dc2 type r b18 on a bend that was long swopping at high revs tryed everything in the end i left baffeld sump on but i cleaned out the pick up pipe changed the vtec solonide and put lighter oil in it dont know which one sorted it but never looked back, worth a shot
 
hello

i get this all the time with my honda vtec race mini, nobody i speak to knowns anything about it or has experienced anything like it, i to dont want to dry sump it as this was ment to be a cheaper engine to run than the a series which mini have.
i have the same symptoms as you its not electrical its because of the g s on corners, this starves the engine of oil and cuts off the vtec to save the bottom end. the vtec needs 30 psi to operate <i think> its so annoying when racing. i have a incar oil pressure gauge and on video replay you can see the pressure drop from 60psi to 20 psi it can take up to 4 seconds for the vtec to come back,
my sump is a standard one but has been modified buy a company called watsons,
i took the sump off and found that the mods made were a cross between a baked bean can and a load of pigeon sh*t.
also although the oil is changed all the time its was so messy in the sump, which carnt be helping.
also watsons had covered the sump gasket in black silicon why i dont no, but a fair amount of this was found by me in the oil pickup which also cannot be helping matters.

i was going to buy a mugan sump but i think ill get a new standard sump new pick up and new oil and filter see if that helps

here is my number if you wanna chat
07931589825
antony
 
Thanks for the reply antony. I would avoid the standard sup in a race car, especially if you are cornering above 1G or racing on undulating circuits.

I have solved this problem, it was the oil pickup and the baffled sump. The spot welds had come loose (I didn't weld it, some dodgy person did) and the pickup was full of crap. Gave it a good clean and acquired a Spoon sump and all is well.

In the last race I did (a one hour endurance race) I never had vtec drop out once, and it was during that race that I set my personal best for that particular circuit, so it wasn't through lack of trying!
 
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