At what rpm are the 5.4 3V creating max hp? I had my truck on the dyno, and for 3 runs it made it's max hp between 3600 - 4100. I have seen other graphs, and they kept making hp up around 5300+.

 

here is my dyno graph, i hope this helps

 

Hi ORM,

Your power should peak in the 4700-4900 rpm range with your mods, assuming the dyno is relatively accurate.

One mistake some people make (we've had a number of people do this, don't ask me why) is to run premium gas on our 87 or 89 octane tuning (or try to run 96 or higher octane on our premium gas tuning), and if you do that in these 5.4 3V engines, then the power will peak much lower than normal, as the engine can't burn enough fuel - instead, it will peak at about like 4100-4200 rpm or even less, so it's critically important that the truck be running on the tune that precisely matches the octane level in the tank, otherwise you will get weird problems like this.

I think I recognize your screen name, so if we tuned your truck, you need to get us your data and we need to have a talk, OK? Thanks, & good luck!

 

Thanks for the graph 05silver.

Mike,
I must of been reading the graph slightly wrong, cause the hp seems to max out around 4500. On the other hand, my tq maxes out below 4000. And the tq falls below the hp around 5300. Does that seem more correct, or not? I have emailed ya'll the datalogging I did during these runs. However, I haven't had a chance to fax over my dyno sheets. Thanks.

 

Hi ORM,

I really can't comment (at least, intelligently) further until you have sent in all of your data and we have had a chance to go over it thoroughly - anything else I would say at this point would only be guessing, so we'll just wait until I can review all of your data, to give us the picture.

 

Mike-
I faxed over the dyno sheets last night. Please contact me when you look these over.
Thanks, Joel.

 

Hi Joel,

We'll review your data and make any changes needed, we do that automatically. If we feel there is an actual problem that we need to discuss, then we'll call the customer - otherwise, we simply make the changes (if any) that may be required, and email that out.

Usually the problem when you see very minor rpm variations in terms of where peak power *seems* to occur is with the dyno's rpm pickup, rather than any actual tuning issue - or looking at a graph instead of the tabular data - meaning the data sheet you are required to provide that shows no graph, but instead just 4 columns of text, displaying rpm, horsepower, torque and the A/F ratio in 100 rpm intervals - *that* is where we look at the data, not the graphs, the graph is only to show the basic shape of the curve, to insure there are not really obvious problems with the vehicle itself.

The only way the engine is not going to peak it's power where it should is if there is something wrong - like the customer using the wrong octane level of fuel for the tune that is installed in the truck, for example - or the dyno facility's rpm pickup being a tad off, etc. Remember, any engine's camshaft profile is what determines where peak power occurs - that is not something that is changed by our tuning.

Just so you know, in terms of timeframe, I would expect it to be a couple of weeks before we get to your datalogging info, as we have to review them in the order they come in - just like we do in the initial tunes in the order that we get the CPW's sent back to us, of course - just FYI so you'll know.