Dyno advice

[stup]

Putting the car through its paces at a local track night next week so booked in at Dyno to have my afr verified against my zeitronix afr readings just to confirm all is ok!
Fuelling is pretty much bang on now,once enrichment kicks in via rpm solenoid the afr at 4200 revs is around 11.5 afr going on to 12.2-12.3 at max revs,before enrichment at 4000 revs afr is 12.6ish so all looks pretty good although may be able to improve slight drop to 11.5 with some further tweeking!

At dyno tomorrow i think the tuner has mobile fans on the floor just not sure if he has fan that will go directly on top of the intercooler area which i think would be best,
So if floor fans are just available will i postion at rear with engine lid open or at sides near rear quarters???
If he does have a fan that can go over the intercooler is it best to have engine lid shut or open??
Anybody tried different methods,if so which is best??

[AngM018]

open if he has something directed on the intercooler. If they are fixed out front of the car, then keep the lid closed as the fins on the lid will direct the air from over the car into the intercooler.

If they dont have a fan that can go directly on the intercooler, then you might want to bring a couple bags of ice in a cooler so you can cool the intercooler between pulls. this may help counteract the lack of airflow.

[930gt-40r]

+1 on the bags of ice.
If he has one of those "turbo fans"- place it on the rear window with a piece of cardboard taped to it directing the air right over the intercooler with the lid closed.

[stup]

Not long home from roll and road to check/confirm afr and do a quick power run!
AVA tuning are up here in scotland,this is where i took the car,although they do not specialise in Porsche they have been in the tuning game for decades and there roll and road figures are always towards the conservative side if anything!.
Quite pleased they had a mobile fan to sit on top of intercooler and had large front fan for oil cooler!

I have completed fresh rebuild approx 3000 miles ago with mods i have mentioned on previous posts and car made 383 rear wheel bhp at just over 5000rpm.
This equals approx 425 flywheel bhp in his opinion!

My zeitronix afr was reading slightly leaner than what his equipment was showing so my car is even more richer midrange than i first thought and even safer up top so looks like more bhp can be gained midrange when i tweek more!
My 1992 964 turbo still runs it standard k27 turbo so even though its set just below 1 bar boost and sees this lower down the rpm, it cant maintain this and is only around 0.9 when the peak bhp was acheived,so looks like maybe a bigger turbo some day will be purchased soon to maintain the flow!

Have you guys got an opinion on converting rearwheel hp to flywheel???
and do you use this calculation for torque....torque = 5252 x bhp divided by rpm you acheived max bhp.

Below is quick mobile camera videos for your viewing.
Steve(Biglicks) has kindly posted these on his youtube account for me

session no.1 is a stepped run with flame at end http://www.youtube.com/watch?v=LawJFxuevJU

no.2 is the run he acheived figures http://www.youtube.com/watch?v=tEnq0o6dnaI


no.3 is my headers cooling down AFTER runs(no wonder you hear of headers cracking) http://www.youtube.com/watch?v=xVdYBJH7RRg

[stup]

bump!

[Craig 930 RS]

1) Lid open, 100%
2) Box fan on IC, with bungees if needed. Bring one from home or buy one!

[copbait73]

Originally Posted by Craig 930 RS

1) Lid open, 100%
2) Box fan on IC, with bungees if needed. Bring one from home or buy one!

At the risk of setting off a protracted debate here how does one rationalize adding forced fans or ICE on the intercooler to obtain "real world conditions" and therefore proper calibrations and true HP?
There is a small pressure positive differential in place between the top of the decklid and the cooling air discharge under the engine at road speed but the IC heat transfer primarily comes from the engine fan draw with the lid shut.
In my mind shut the lid, make the pull that is real world. Everything else is cooking the books.

[Craig 930 RS]

Good points
~~~~~~~
You'd be amazed how much air 'leaks' past:

The entire perimeter of the engine lid
Through the "seals" on the sides and front of the engine

Plus, the dyno tech usually needs/prefers the lid open for the sensor wires

[Craig 930 RS]

Using my IC inlet/outlet Andial temp gauge as a source - the IC does not get *that* hot after each run - hell, they only last a few seconds or so.
But the heat that is in there does remain and increases after the 2nd and 3rd runs -- without a fan, even more so.
Slap a fan on the IC, dont give it any more intense thought, and be done with it. ;-)

*Look at the dyno run move I have posted in my sig line; 2k to 6.8k in 8 seconds*

[930gt-40r]

This is how we do it in the north east....
http://youtube.com/watch?v=xdm92VUkV7g&feature=related

[copbait73]

Originally Posted by Craig 930 RS

Using my IC inlet/outlet Andial temp gauge as a source - the IC does not get *that* hot after each run - hell, they only last a few seconds or so.
But the heat that is in there does remain and increases after the 2nd and 3rd runs -- without a fan, even more so.
Slap a fan on the IC, dont give it any more intense thought, and be done with it. ;-)

*Look at the dyno run move I have posted in my sig line; 2k to 6.8k in 8 seconds*

Which is also to my point that a closed lid pull is then only representative of a
0-??? MPH accel and not track conditions.
ICE is representative of nothing except possibly someone leaving their car out in a snow storm overnight then driving off in the morning at full throttle.

[Craig 930 RS]

Track = higher degree of probability that air is actually making it through the IC in large amounts at all times.
Dyno = short bursts with very little air in the IC between runs.

Put a fan on it.

[930gt-40r]

ICE+ fan= safe
Short of dynoing your car in a wind tunnel, there is no way to accurately reproduce the cooling affect of 100+ MPH airflow.