I know this is real noobish but, I am fixing to buy a 94 GSR and I just want to make sure that VTEC engages properly. It is completely stock, so was just hoping that I could hear or feel it engage. I know that vtec engages at 5400 rpms (approximate)

 

Vtec engages at 4400, the secondary intake runners open up at 5400 (which people often mistake for vtec).

No, you won't hear it or feel it on a stock gsr.

 

VTEC engagement is actually 5000rpm on the 96 and up motors, and the IAB is 5750rpm on all GSRs

And yes you can hear and feel it on a stock GSR!
My bone stock 92' GSR B17 has a big difference when VTEC comes on both in noise and seat of the pants... yes it even has a stock exhaust and air intake.
The higher the load ont he motor, the more you will notice it. (try it in 4th gear.)


Modified by Mochanic at 12:50 AM 10/10/2003

 

i drove my friends 98gsr and i didnt feel the vtec just got really loud around 6...the power band felt smooth no drop off in power like my old d16y7 when i used to rev the **** out of it.... now i got the jdm b18c sir. i guess im just used to my killer vtec and a stock gsr just feels damn right slow

99dx coupe
94 jdm b18c
179.4hp
128tq

 

thats what i was wondering..i got a jdm b16 and i just got it running recently so i took it around the block and i didnt notice any vtec engagement it was smooth but i could only get to 3rd gear cuz neighbors getting pissed..is that normal?

 

the higher the load, the more its noticeable, so yes that would be normal in the lower gears.

 

The purpose of vtec is to have a smooth high and low rpm band, if you can really feel vtec kick in your vtec engagement is at the wrong point.

And its 4400, even on 96+ B18C1's

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
Coupled with VTEC, you can see the GS-R engine has three stages of operation.

Stage 1 (0-4400 RPM): Low-lift cam lobe and long intake runners.

Stage 2 (4400-5800 RPM): High-lift cam lobe and long intake runners.

Stage 3 (5800+ RPM): High-lift cam lobe and short intake runners.
</TD></TR></TABLE>

http://www.team-integra.net/se...D=246

 

a low powerband? I thought you wanted a broad powerband? You should at least be able to hear vtec though? Maybe not feel...

 

Why should you be able to hear vtec?

What happens when vtec engages? Oil is allowed into the center rocker and locks the valve rockers together so the center lobe is used instead of the less aggresive outer two.

This is not something you are going to hear on a stock engine.

 

alright cool...so basically all I should be able to notice is a broad powerband.

 

When my 94 GSR was stock, the VTEC switch at 4400 was only a subtle change in tone. The runners opening at 5800 was very obvious.

 

my 98 gsr is very smooth when vtec is engaged. I almost don't notice it unless I pay attention but in an ITR, it is very noticible, also in a prelude. civic si's are smooth also.

 

[QUOTE=Mochanic]VTEC engagement is actually 5000rpm on the 96 and up motors, and the IAB is 5750rpm on all GSRsQUOTE]

Not on yours it isn't.

an OBD2 GSR will probably be even a little less noticable, as it has a bunch of emissions overhead, and just isn't making MEAN power.

CAI will help you hear it more. Exhaust will help you hear it more. On the B16s I've heard, it screams, thats a SIR, and a 99 SI (with loud fart can exhaust...)

Everyone has an opinion on what values Vtec and IAB kick in. I respect everyone's opinion, but don't know whose opinion to respect the most.

What I have for a stock rom, opened up in a rom editor says
vtec: 4875
IAB: 5750

Ok, I compared 3 roms, USDM, and JDM. All stock, and that is going to be my final, answer, take it for what you will. OH yeah, OBD1, forgot to mention that.

-PHiZ

 

the most reliable way to find out if your vtec is operating correctly is to backprobe the connecter on the vtec solenoid, hook the red lead from a multimeter up to it, ground the other lead, route the multi meter into the car, set the multi meter on dc volts, drive the car in first or second gear, watch the voltage on the meter go from 0 to 11.0-12.0 volts. if that is working then most likely the mechanical mechanism is working. if the mechanism isn't working, you can do an air hose test on the head. this is described in the factory service manual.

 

In my prelude I feel it and hear it

 

Yeah like sleepyEk said if you think its fucked up, you can take a wire from the battery and touch it to the VTEC solonid (disconnect it from engine harness first!!) and if its working you'll hear it *click*!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GPoodle &raquo;</TD></TR><TR><TD CLASS="quote">Yeah like sleepyEk said if you think its fucked up, you can take a wire from the battery and touch it to the VTEC solonid (disconnect it from engine harness first!!) and if its working you'll hear it *click*!</TD></TR></TABLE>

Hrm 12volts yes. But high amperage. I dunno.

Anyone have a procedure for IABs? some generations are ground activated, some are hot activated, right?

-PHiZ