Modification Question
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Junior Member
Joined: May 2003
Posts: 63
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From: Chicago area (Plainfield)
2004 E55 White
Modification Question
My question is pretty simple. Is a pulley and computer upgrade worth doing performance wise? I am going to put some limits on the answers and I will explain why. First of all I have a 2004 E55 that is stock except for K&N filters, which probably don’t do anything for HP. I have taken it to the track twice with the following results.
When the car is hot (no special cool down or ice on the supercharger) it runs between 12:80 and 12:90 at 109 MPH. My 60 foot times are not bad, between 1.80 and 1.90 (this was with the stock Conti’s). When I let it cool down for an hour (it was still pretty warm) it ran a 12:57 @ 113. I think if it was completely cold it might run 12:40’s. This was in 80 degree weather in the Chicago area 660 feet above sea level.
Now for the question. If I do a Renntech pulley and computer tune, what can I expect to gain? Taking into account that I am speaking about a car running under normal operating temperatures (about 85 degrees Celsius). I am not really interested in what it can do under maximum cooling conditions, as these are not normal when the car is driven on the street.
I am thinking that since it runs quite a bit slower when not cooled down, the pulley and tune might not be as effective under normal (hot) driving conditions. In other words, if the computer is pulling timing with the stock pulley, won’t it just pull more with the Renntech stuff. I think I will call Renntech to see what they say, but answers from some of the people that have upgraded their cars would be much more believable.
When the car is hot (no special cool down or ice on the supercharger) it runs between 12:80 and 12:90 at 109 MPH. My 60 foot times are not bad, between 1.80 and 1.90 (this was with the stock Conti’s). When I let it cool down for an hour (it was still pretty warm) it ran a 12:57 @ 113. I think if it was completely cold it might run 12:40’s. This was in 80 degree weather in the Chicago area 660 feet above sea level.
Now for the question. If I do a Renntech pulley and computer tune, what can I expect to gain? Taking into account that I am speaking about a car running under normal operating temperatures (about 85 degrees Celsius). I am not really interested in what it can do under maximum cooling conditions, as these are not normal when the car is driven on the street.
I am thinking that since it runs quite a bit slower when not cooled down, the pulley and tune might not be as effective under normal (hot) driving conditions. In other words, if the computer is pulling timing with the stock pulley, won’t it just pull more with the Renntech stuff. I think I will call Renntech to see what they say, but answers from some of the people that have upgraded their cars would be much more believable.
