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Re: H&H actually used a stroked 4.0 V8 - 4.4 ( (archive)

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Posted by STT on July 07, 2000 at 10:49:54:

In Reply to: Re: H&H actually used a stroked 4.0 V8 - 4.4 ( posted by Hans on July 07, 2000 at 10:00:36:

: Re. Well, I have MK hardware and it is Rotrex (KKK turbine compressor side, NO OFFENCE TO MINORITIES, IT IS THE NAME OF THE COMPRESSOR). I also have two pullies - one for 7.5 psi boost and another for 9 psi boost.

: Do you mean that you are using a MK Motorsports supercharger on your 540i? Back in 1998 when they first brought out the conversion, they used a vortech supercharger. They must have changed.

: Re. : With 7.5 boost on Vortech POS with 70% adiabatic efficiency and no aftercooling you can hardly get over 410 hp on pump gas.

: I have seen over 420hp with no aftercooling at 6 psi on a 4.4 litre vortech supercharged car.

: Hans

Not yet. I bought all the hardware, not sofware, two month ago - MK wanted 16,000DM and dollar was strong. I was mainly interested in bracket, turbine and tubing. I want to bring 4.4 to around 400hp naturally aspirated with some cosmetic mods like RD cams, t-body, AMM and Lim's sofware first. Then, and only then I will supercharge it.

Here are the arguments that do not let me to beleive in your numbers. Please feel free to rebuttle them.

Let's say you increase pressure at the intake by one bar (14.7 psi). Disregarding associated losses in the intake track you will be able to provide engine with twice as much oxigen and you will increase power by a factor of two. Therefore, if you blow 6psi you, in the ideal world, will be able to get extra 41% of power. Now, with 100% adiabatic efficiency of the blower you will increase intake temperature by approximately 50 degrees. If adiabatic efficiency is 70% then there is an extra in 20 degrees crease in temperature. So, there is a total of 70 degrees increase. These are estimates and they may be off by several degrees. Now, each 10 degrees in temperature increase are roughly equal to loss of 1% in hp. Therefore, with this setup the power increase will be roughly 34%.

Let's say you have 4.4 with Lim's software, i.e. 300-305hp. Blown version should produce around 400hp in the best case scenario. Take into account intake losses of about 2-3% and you end up with no more then 390hp (If, of course Garret Lim had a part in it).

Engine hp does not mean shit to me. I only care about rear wheel hp. My guess is that cars you are talking about were making no more 330 at the wheels and Dinan will ba making lower 320's.

Again, the above estimates are subject to debate and you are, Hans, are welcome to question them.



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