dyno b20z vtec issue
 

Dynod ma b20z vtec and at around 7k my power was dropping around 10 hp. My tuner said it was due to me having a b20 oil pump and i thought he may have been right. But, it turns out i do have a sir fuel pump now what could it be...I left during the dyno cause i thought that was the problem. I will post up the graph as oon as i grab it tonight. BUt, what could it be...made around 180 whp at 7 k and 140 wheel tq ..its a b20z with cams and type r intake and tb, cam gears , header full exhaust..and other basic stuff...clutch and flywheel...Now, has anyone even herd of this happening, cause my mechanic told me once in vtec it will stay in vtec, its an electronic thing..And i did not hear it get out of vtec. So, what could it be..If it was a oil pump and the dyno graph is dipping, it cant be due to the oil pump, cause the first thing that would happen is we would hear vtec cut out..And i ddint hear it..so...

how did u build the motor? did u use a LS/B20vtec kit? with gsr t-belt and gsr water pump? did u get the motor tunned b4 dyno?

All B series oil pumps are the same.

Power drop, perhaps the cams don't make power after 7K? The graph has to drop somewhere, it can't climb up forever.

not all b-series oil pumps are the same....all b-series oil pumps from 98+ are the same....so the b20 oil pump is the same oil pump as the 98+ GSR/ITR/B16.....its all the same part number, check it out.

As for an oil pump causing a loss of power?...never heard that one before.

Whats the problem with 180whp and 140ft/lbs? Sounds like a decent setup to me.
Be happy that you don't have to rev the bag out of the engine to make that kind of power.
I'd also be interested to see what kind of ignition timing you are running up past 7k.

My bad, I forgot the year thing.

everyone thinks that a b20/vtec will make 220 hp on a stock bottom end etc...it just aint so.

Replace your o2 sensor.

Oh how we missed you here buddy....welcome back.:goof:

Hello there guys, the problem we had and the reason we stopped tuning this car, was that the ECU indicated a code 22 (VTEC oil pressure switch) it threw this code after VTEC had already been engaged for a few hundred RPM (not right as VTEC engaged) backed up by the dyno graph showing a definite lose of power indicative of VTEC disengaging. Basically there are 2 main reasons why this would happen. One is that there could be a wiring issue with the car that caused the error code, but those do not usually take that much time to be thrown and usually happen as soon as VTEC engages. The more worrisome reason for this error code to happen, is that there is not actually enough oil pressure to maintain VTEC engagement. So to err on the side of caution and instead of continuing on which could have potentially damaged the motor, I advised Nadir that it was in his best interest to install a oil pressure gauge to verify that the oil pump was indeed providing enough oil pressure. Hope that helps clear this up a bit. I'm sure there will be continued discussion on this topic, but that is all i will be contributing.

So you were the tuner who tuned his car?
Just out of curiosity, what kind of timing are you running (specifically in vtec up top)?
What timing maps did you start with p30 or p72?
Not questioning your tuning here, just strictly out of curiosity.

I agree, an oil pressure guage would definately be a good idea.

But from my experiences, you can definately tell when/if vtec is disengaging, or isn't working at all for that matter.

^^I have to agree with zeeman here.

You KNOW when vtec is in or out....especially with an intake..

If the oil pressure is not high enough, does the ecu automatically disengage vtec? (I'm learnin...lol).

Zeeman, you said b series oil pumps older than 98 are different right? So if his b20 block is older than 98, are those oil pumps not as strong as the 98+ b series pumps?

If for any reason oil pressure dropped at that RPM, then yes the vtec oil pressure switch would sense this and tell the ECU to disengage VTEC. Judging by the big horsepower lose and dip your talking about at 7,000 RPM then I would have to say that oil pressure was lost. Not necessarily did you lose oil flow but possibly oil pressure.

What size is the oil line to the head??? I'm curious....also, has your oil filter been changed recently (did you have the oil changed?) some causes for lose of oil pressure may be from a gummed-up oil filter.

I would say do as FLATBLACK mentioned. Get your self a cheap oil pressure gauge and tee it in to the line that goes to the head for VTEC...see what pressures your getting at start-up and when it's warm. Also watch the oil pressure as you accelerate up through VTEC and then into your problem area.

Post up some results.

Just keep in mind also....

Use a good tuner, some guys just dont care about us smaller guys, and will keep tuning even when small problems like this occur. Make sure your tuner doesnt keep revving your motor if there isnt oil pressure. I know I had some problems on the dyno with my car and my tuner from t e k n o t i k stopped the run right away.

flatback is nick from t e k no tik.. so the guy went to t e k n o ti k.

oh i see, i didnt realize....

so what did you think of his tuning otherwise? mine seems good so far, but i'm not driving it everyday. i'll post some more info once i start daily driving it

whats wrong with 180whp?

nothing...

i don't see anything wrong with 180whp either.
But for the power to start dropping off at 7k isn't exactly what i'd say is normal. I've seen b20vtecs built with less mods make similar power on a basemap running stock exhaust manifold and 2" exhaust.
What cams are you using?....ITR?

what are you using for management?
crome datalogs will log vtec engagment, go through and see if/when vtec is engaging/disengaging, check it with your dyno plot

yes im using type r cams...The car was making the 178 wheel hp at i think 6-6.5 rpm so i know that i could have got more out of the car....And the first pull the code 22 was thrown...But the second pull and the rest of the pulls did not throw a code...But, i do believe i have a b16 oil pump...As for the fittings, i got my ls oil line kit from my tuner at T E K N O T I K so i know its good stuff and proper for my setup....Now, i have ordered a oil pressure gauge and i will post my dyno as soon as i get it from the tuner....