do guru chips adjust rev limit?
 

i couldnt find the info on the website

oops, nevermind

Nope, we keep the factory redline at 6480rpm. No use revving too high since the torque drops off fairly quickly. Also the stock injectors hit 100% duty-cycle at around 5500-6000rpm and at 6500rpm, the mixture has gone from 12.5:1 up to about 13.2:1 which is about as lean as we want to go.

On a street car that sees occasional acceleration runs and spends minimal time in the uppper RPMs, this isn't too much of a concern. But track-driven cars that see full-throttle at high-RPMs for extended periods can blow headgaskets easily of we allow them to rev much higher. In which case, upgrading the injectors to 55-lb/hr to reduce the duty-cycle down to a more reasonable 63% is advisable.

thanks for the info

Does the mixture stay at 12.5:1 if one should upgrade to larger injectors or is the mixture fixed in the chips?

you'd need a chip for that particular application (injector size)

nothing beats fine tuning and customizing the combo

[quote]Originally posted by Levish:
<strong>you'd need a chip for that particular application (injector size)

nothing beats fine tuning and customizing the combo</strong><hr></blockquote>

But we are talking about the Guru Racing chips here and they have a switch for different injector sizes...

But yes, fine tuning and customizing is of course better. But at the same time much more expensive..

Yup, our chips are switchable between the stock 34.6-lb/hr injectors as well as aftermarket 55/65/75-lb/hr ones as well. The duty-cycle is scaled back precisely to the percentage difference between the flow rates to provide exactly the same amount of fuel.

There is also a secondary aggressive ignition map that's available for people who want to use 96-octane gasoline (2-gallons toluene per tank or 50/50 mix with 100-octane race gas).

Danno,
How do you "toggle" between the injector settings and the secondary timing map?

[quote]Originally posted by Russ Murphy:
<strong>Danno,
How do you "toggle" between the injector settings and the secondary timing map?</strong><hr></blockquote>

Via the FQS (fuel quality) rotary switch.
Danno has a great write up on his Racer X site.

<img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />

Shh.... only chip upgrade buyers are privvy to our secrets !!! Wanna buy a set to try out? :D