Tuning ... You’re Only As Good As Your Tools

[Headsex]

In shootout mode, the correction factor is calculated automatically based on various temp/humitiy/atmo presure. And its printed along the bottom of the dyno graph..

have a quick read of this first post here http://www.ls1.com.au/forum/archive/index.php/t-58222.html

This guy does a good write up, especially makes alot of good points about the way the mainline/dynolog software works but makes refrences to the dyno dynamics also.

Down the quarter mile.. MPH is a good indication of what power the car produces.. Given you need XXX power to get to XXX mph down the straight.. considering all our cars weigh about the same, you can tell who has what power and who doesnt.

[senna_T]

so far with my attempts at the strip I have managed 112mph when running 313rwkw, the time I went back with 340 it was very hot and I couldn't improve, only 113mph.

Running Street tyres @~23psi and T56 box, fullweight 1890kg

[blupwr]

Danny,

many people modify their base spark or borderline knock table to see the given spark that a car in a particular circumstance will "like".

I am a fan of reducing this table, and using MBT as an "upper limit" depending on how inconsistent the air cooling system is.

Further to this - your spark retard for ACT - have you considered raising the lower levels as a spark adder for premium conditions (cooler) with mods to the mult table itself THEN going into the usual retards as temps rise?

this can greatly reduce knock "learn" and is a technique I picked up tuning our NON intercooled Boss systems, and I have since applied it to the turbo's we tune, esp in the slow correction value.

Its helped me in this situation, may be helpful or not for you.

Regards

Chris

Bluepower Racing Developments.

[DesFlurane]

For reference I ran 112 with 295 rwKw.

Originally I believed I had 314, which is what my dyno plot showed. Took the car to another shop and had it re dynoed after the 1/4 run. Showed 295, even the tuner said that my car didn't have 314 after he drove it before the dyno run.

That guy now tunes my car.

[senna_T]

were you running street tyres DesFlurane?

Sorry to get off topic again!

[Headsex]

so far with my attempts at the strip I have managed 112mph when running 313rwkw, the time I went back with 340 it was very hot and I couldn't improve, only 113mph.

Running Street tyres @~23psi and T56 box, fullweight 1890kg

Now see, I ran 114mph back when I had 302rwkw when I had the standard exhaust. Which given the moroso calculator and everyone elses results, its about right.

Another car I tuned also with 308rwkw ran 114mph on street tyres, although his et wasn't as special with a 12.1 and a wheelspinning 2.1 60foot the mph was there indicative of the power its made.

I have since ran 121mph with not a good et, but that was due to poor traction, and poor 60foot. But that's not how the car currently sits, I'm chasing some 17" et streets to do it all again.

So even your figure of 313rwkw is a bit happy given the mph you run. With 340rwkw you should be in the 120's

Desfluranes power and mph is on the money

[senna_T]

that's fair enough, at the end of the day its all about how it feels on the street and whether the customer is happy with the car. I'll be going to the track again when the weather is a bit cooler and I'll see how it runs.

But this thread was not about drag racing or power figures, so lets get back on topic and everyone can read what you have acheived with your testing and tuning Danny.

[Headsex]

Futher to this.. Mauz, and Mark(fsix) both have power around the 390 - 400rwkw, as an indication, their mile per hour is 130 and 132mph.. Definate indication of their power..

So, for 350rwkw, you need to be smack bang in between 115mph and 130mph.. Regardless of tyres

[Headsex]

that's fair enough, at the end of the day its all about how it feels on the street and whether the customer is happy with the car. I'll be going to the track again when the weather is a bit cooler and I'll see how it runs.

EXACTLY.. This is the point im trying to get to.. Dyno figures is not what makes a customer happy, although 90% of people here believe that.

One good example is.. a car I tuned to 300rwkw.. and another car tuned to approx 360rwkw(by another tuner).. On the street, they were neck and neck, usually with the lower powered car infront by about a car.

There is a hell of a lot more in a tune than the big fluffy number at the top of the dyno graph in how the car will perform in real world situations (ie, the street)

I had one customer, who believed he had a 330rwkw tune by HPF.. after I got my hands on it.. the absolute most power I could get out of it was 302rwkw, and that was leaning on the timing really hard, so much so I pulled some timing out before I let it go back to the customer, so infact it only has approx 295rwkw. But at the drag strip he beat his last time by the likes of 4 tenths and 2 mph or something. Although you could tell he was disapointed at his lack of a 300rwkw dyno sheet, he kept saying it pulled harder the whole rpm rev range than the 330rwkw tune he had previously.

I've even found that pulling timing out under 4500rpm and sacraficing bottom end, will make the dyno show higher power as the rate of acceleration of the roller is higher at 5000rpm than it would be if there was more timing/power under 4500rpm.. On the street, these kinda tunes lack bottom end, and really are a "dyno queen" type tune... its essentially "Spiking" the dyno, much you can do with boost spikes.

Edited 15/02/08 12:20 AM by Headsex

[senna_T]

would their gearbox have something to do with this - as in the auto's quicker shifts vs. the manual, surely the time taken to shift gears can effect the cars ability to keep raising the speed?