To be specific.....DYNOJET.....

so....since this is not a LOADING dyno, how accurate are the A/F readings?

just asking....

talking to a friend who sujjested that you will run leaner on the street because the car is not under as much load on dyno as it would be on the street?

anyone chime in on this??

 

The A/F ratios are as accurate as the wideband measuring it. Dynojet is not load capable so it cannot represent the loads seen on the steet but the A/F ratios read on it will be accurate for the load that the car is seeing.Its not that the A/F is "OFF" it is just not the same A/F that the car will read on the street because of the load differences...

 

correct....

 

Keep in mind, on a dynojet, your doing full-throttle runs. On the street, driving normal with partial-throttle will be different but not by much.

A dyno like Dyno Dynamics can help you do that. If go in there and leanit on partial-throttle, you get better MPG. Running too lean won't hurt on partial-throttle. Well, depanding on how high is your ignition timing tables and how hot is outside,like ******* florida,lol

 

chad it sounds like you know what's going on.

 

keep in mind dynoject now offers an option for loading the dyno. So you can do part throttle tuning on a dynojet now. It is an option so the dyno garages out there don't have to buy a whole new unit, just an upgrade. A dyno near me has it, haven't used but will utilize it.

The only thing you need to keep in mind is if they put the EGA in the tailpipe the AFR readings when plotted against RPM will be off by about 500 rpm because it takes time for the exhaust to flow all the way thru.

s

 

K... So... Let's let the newbie axe a quechin...

If you "tune" the car on the dynojet with no load... The car will not be properly tuned for the street/track, correct?

I don't get it... (There are quite a few things I don't get... isn't that right Chad? ;-)

Bye the way, sorry to resurect 2 weeks ago.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aut0tek &raquo;</TD></TR><TR><TD CLASS="quote">K... So... Let's let the newbie axe a quechin...

If you "tune" the car on the dynojet with no load... The car will not be properly tuned for the street/track, correct?

I don't get it... (There are quite a few things I don't get... isn't that right Chad? ;-)

Bye the way, sorry to resurect 2 weeks ago.</TD></TR></TABLE>

This is not necessarily true. If you tune within a range of A/F, you won't be that far off on the street. The load is different between the street and a dynojet, and the difference from air resistance, car weight, tires, and other environment factors all play a role on a engine. The conversation I had with Chad about this was that I said a car usually runs a bit leaner on the street versus the dyno because of the above factors. It has been tested by a people I know with Supras that they can run almost 1 full point leaner on the street than on the dyno. Again, a big difference between a Supra chassis and a Honda chassis is weight. If the load is higher on the car, but receives the same amount of fuel, you are going to run leaner. On a Honda, I don't think it will be nearly close to a point. Maybe .5 A/F at most.