i just bought a 10" tach. what should i set the shift light to come on at? so that i get the full amount of vtec with out hitting the limiter ? its the stock ecu

 

just go out and try it. each car is different. run the car in 2 or 3 until the needle bounces and remember what that rpm is or if your tach has a recall function use that, and set it 200 rpm lower.

 

10" tach...holy shit thats huge

 

lol i dont know what the hell i was thinking lol its a 5" tach lol my bad

 

maybe you can answer this..

why do people buy a 5" tach for a car that has a 4" tach standard? that's just always confused me.

 

The ECU is stock, but is the rest of the motor?

If your car's completely stock, you can shift at anything over 8000 and stay on the cam...provided you're a decently quick shifter.

 

Dunno about the size deal Dave, I guess that is standard race car prep.

As for the reason to buy the tach, there are 2 good reasons, 1) accuracy (usually OE are off and the ITR is no exception) 2) ability to add a shift light ( which is handy when glancing at the tach is not an option).

 

Of course, but then, one isn't even reusing the stock gauges I hope. We don't. :shrug: But I think this guy is driving a street car anyways.

[quote:99a6a6328c]1) accuracy (usually OE are off and the ITR is no exception)[/quote:99a6a6328c]

I agree that stock tachs are inaccurate in how they read, however, they are consistant. I know my car hits the limiter at x indicated RPM. It ALWAYS hits it at the same RPM. Does it really matter what it shows as long as you know where that is?

[quote:99a6a6328c] 2) ability to add a shift light ( which is handy when glancing at the tach is not an option).[/quote:99a6a6328c]

You can add one without a shift light too. A low intesity LED, a dali racing shift light setup and some wiring = in-helmet shift light connecting with the same wires two way comms uses :P

or for a more 'common' approach, a number of companies make adjustable lights that just read the tach signal and light up with needed. Not as adjustable, I agree, but still works.

 

Back to his original question...

I'd say set the light at 8000-8200... That's what I'd shift at with the stock ECU... You should have just enough time before fuel dump... If you are paying attention...

Personally I like the stock tach (though I'm running of of room on it... better valvetrain ) and shifting by "feel" and a quick glance of course...

 

i got a question. when you buy a aftermarket tach (never did) do you hook it up to the same wiring that the factory tack is hooked up to. if so then wouldn't the aftermarket be just as inaccurate.