Posi Port Dyno Numbers

[hpbyhermann]

The way I set up the tune allows for this.

I guess conventional wisdom on the matter has changed due to much testing. I agree, back 3-4 years ago spinning up a 'heaton' with pulleys meant about 19 max on timing and 20-21 if you wanted to push it. If 22-23 is safe then it is safe. I guess I have been out of the loop too long. Is this just if it is ported? Does it bring the air charge temp down enough?

Jaimie

The A/F is an actual 11.10 and this is just the fast tune of the three I did for Mark's application. This is for controlled environments like at the track with adequate cooldown. His daily on the street "driver" tune is 21 degrees with adequate
IAT reductions in place for total safety. Again, this is an area the tuner has to use their expertise and exercise caution! The final product is only as good as the tuner and the tuner's equipment.....if the guy just has a tailpipe A/F machine for gathering data you can believe the tune you get based on that data will be nowhere near as accurate or safe as the guy with the Horiba or AFM-1000 A/F machines! In other words be sure about your data before you step up your tuning. :thumbsup: Hermann

 

[Posi]

Thanks Jake.. best explanation i've ever seen... I understood that it was a different calculation but never knew what values were different.


All you guys seem to be running a lot of timing as well ... is 22.5 seriously a safe street tune?

I'm only at 18-19 degrees.. wonder how much power the extra timing would make?


Also, You see a few videos on youtube with twin screw guys making 570ish at 16psi.. I'd say that if you was going to run no more boost than this, that the extra $$ isn't worth paying vs. a race port!

Quite honestly I wouldn't get a tune for my car with 93 octane with less than 23*'s timing or let it leave my Tuner's shop. There's a lot of us running around with it with zero problems for many years now. Maybe and I mean maybe if you or your tuner want to be safe run 21*'s minimum on 93 octane. If you have a tuner that won't do at least 21*'s on a 93 tune then go somewhere else. No matter the time of year.

Like Hermann says though make sure that a/f ratio is dead nuts.

 

[THE_EVIL_TW1N]

Here are two different runs, A/F didn't record for the first run due it being left off on the dyno stack by mistake. (I turn it off between runs and was making a long adjustment to the tune and simply forgot it) I log data and A/F in the car so it is just redundant data. First off the car only is a 2 lb. lower with a 2.80 upper. Mark runs regular 93 octane pump gas with no additives so everything is conservative for long engine life. His fuel system is stock with a BAP and wiring upgrade for the BAP. Stock injectors are still in use and work fine with the proper tune adjustments.:beer: The pump gas here has 10% Ethanol added so the Stoich. value is adjusted accordingly. WOT A/F is set at 11.10 for safety. My in the car data logging system uses a lab quality AFM-1000 A/F logger and another complete AFM-1000 is used on the dyno data stack. The in the car unit's sensor is located right after the collector (note, this car still has factory manifolds, no headers here!:dw The sensor for the dyno stack is located in the rear O-2 sensor holes and read .2 leaner (example, 11.10 in the front, 11.30 in the rear) than actual at the front position to to being further down stream. This is a street setup, only 22.5 timing and actual 11.10 A/F. I was surprised to say the least with the results. :rockon: We had and still don't have any intentions to race dyno #'s.....not my thing. This is what it is, and if he wanted to we could make more power with a 4 lb. lower and Torco added for more aggressive tuning. It was tuned in this fashion because it shows what could be done AND DRIVEN on a daily basis, not a iced down on the edge dyno setup. :rockon: Mark has one hell of a setup to be proud of. :thumbsup: These sheets are shown in SAE and STD for your viewing enjoyment. Hermann

who is "mark"? boobinspector? or cozmo?

 

[Lights of Speed]

those are amazing numbers bro, im almost tempted to buy a posi eaton myself just to see how i would like it!

 

[TRBO VNM]

who is "mark"? boobinspector? or cozmo?

boobinspector, although I don't know cozmo's name

 

[Jaimie03Cobra]

Thank for the timing explaination Hermann. Like I said, I have been out of the loop for a while.

Jaimie