Dick Dawson

My car has a cup type rear exhaust, and a RUF hot film (allegedly). I have no idea of the power output other than it feels quick!

I understood the hot film system allowed more accurate mesurement of the mass of the air entering the engine thus allowing more accurate fuelling and hence power. Without it the car must be set up to allow for a hot day and thinner air as well as a cold day and denser air.

The 993 for instance uses hot film and out of the box has much more power.

What gains this gives I don't know or if other methods can achieve the same result at less cost.

Adrian

Dear Dick,
The MAF does provide a muchmore accurate measurement. The problem is the 964 series DMEs cannot use this data and the MAF output is effectively converted back into an Airflow Sensor output that the 964 DME can understand. The end result at best is a more accurate airflow sensor input to the DME but again the poor old DME does not quite know what to do with this more accurate data. End result is little or no improvements. If you pay for the DME to be remapped you may see some very slight gains. Certainly in my opinion not worth the financial outlay. I guess the best comparison would be trying to replace the old IBM 4.77MHz microprocessor in the first computers with a 233MHZ processor but installing it into the old motherboard.
Ciao,
Adrian
911C4

SteveW@stig

[quote]Originally posted by Dick Dawson:
<strong>
I understood the hot film system allowed more accurate mesurement of the mass of the air entering the engine thus allowing more accurate fuelling and hence power. Without it the car must be set up to allow for a hot day and thinner air as well as a cold day and denser air.
</strong><hr></blockquote>

The 964 DME also looks at inlet air temp and atmospheric pressure to provide the correct offsets for the air flow. As Adrian says the 964 DME can not take advantage of the more accurate measurements of the MAF because it does not know how. There is a school of thought that says the MAF is less restrictive to the air flow and thus gives more power. I am going to prove this one way or the other by using a vacuum guage when the car is next on the dyno.

Dick Dawson

Interesting. All I can say is I am glad the previous owner forked out for the work!!!

tonytaylor

Dick Dawson
I, for one would be interested to compare your rwbhp with mine and Steve.
I was charged £35 for my run at Astmoor garage Runcorn , which ic close to you.
Go on, give them a call!!

Dick Dawson

Do you have their details?

I have sent an email to RUF to see if the thing on my car was put on by them and if so what they think it does to the power.

SteveW@stig

[quote]Originally posted by tonytaylor:
<strong>Dick Dawson
I, for one would be interested to compare your rwbhp with mine and Steve.
I was charged £35 for my run at Astmoor garage Runcorn , which ic close to you.
Go on, give them a call!!</strong><hr></blockquote>

Near is a relative term Near as in the UK but Runcorn is a couple of hours drive away at least.

What result did you get on your run and what is the set up on your 964?

tonytaylor

Dick Dawson
Their address is on the dyno chart at this link <a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=4&t=001956" target="_blank">web page dyno chart</a>

Steve
We have discussed my set up previously (MAF, AMD custom chip,big bore throttle bodies, cat bypass - 250.6 rwbhp)
Sorry, I meant Runcorn was close to Dick in Bolton

SteveW@stig

Interesting, you get another 25rwbhp with throttle body and MAF. As I said I will be going over the intake system with a vacuum gauge to see where the losses are or are not.

Your results are better than those from Germany
<a href="http://www.jarke.de/porsche/964powermeasurement.htm" target="_blank">http://www.jarke.de/porsche/964powermeasurement.htm</a>

These get prety much what I get????