Summit Racing underdrive?
Thread Starter
11 Second Club
iTrader: (24)
Joined: Mar 2008
Posts: 2,554
Likes: 2
From: North East, MD
I call that 12 lbs. What does the stocker weigh? Don't know how deep the belt sits in the groove on the SLP units but this one has a nice clear finish (clear powdercoat I believe) and pretty decent depth to hold the belt.
Thread Starter
11 Second Club
iTrader: (24)
Joined: Mar 2008
Posts: 2,554
Likes: 2
From: North East, MD
I looked around at how much the new and used ones were going for and it was a little nuts. This is a high quality SFI approved 25% underdrive with good instructions on install, belts and bolt to take the guess-work out of it. Don't think anyone will be disappointed!
I can tell the ribs are deeper on that Summit. It looks like a good buy. Like others have said, 25% underdrive is 25% underdrive so I see no need to pay more for something else.
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Verdad Gallardo When I tested the car for any negative changes, the only thing I noticed after driving for awhile is the volts dropped to 13.0 with everything on. Still acceptable, but I might bump the idle to 900 with the Predator to compensate. If I rev the idle to 900 with the pedal, The volt gauge moves past 13 volts. I notice no temp changes and I live in the desert. A/C and steering both seem the same as before. I won't know for sure what kind of gains it gave me until I can get to the track hopefully next weekend.
I went to the track last night and got a few runs in to see if the UD pulley helped my times. Well, I think my expectations were a little too high because it didn't help me that much. I would say I maybe gained 3 hp. My best time was 14.149 at 7000+ DA before the pulley and my best time last night was 14.120 with similar DA and 60' but more humid. My mph was pretty much the same as well. I know this is not an accurate comparison, but I did expect better times. I guess being above 5000ft takes more hp away than I thought.
I think it's time for more major mods to make a real difference. I can say that all my small mods combined reduced my et about 4 tenths over stock.
I think it's time for more major mods to make a real difference. I can say that all my small mods combined reduced my et about 4 tenths over stock.
Last edited by jrcws6; Jul 13, 2008 at 12:19 PM.
I would be more interested to see if it these 25% pulleys gain anything on the track. 1 tenth a 1 mph would be nice. I think the lightest pulley you can find tho would be the best bet to gain anything.
TECH Apprentice
Joined: Jun 2006
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I went to the track last night and got a few runs in to see if the UD pulley helped my times. Well, I think my expectations were a little too high because it didn't help me that much. I would say I maybe gained 3 hp. My best time was 14.149 at 7000+ DA before the pulley and my best time last night was 14.120 with similar DA and 60' but more humid. My mph was pretty much the same as well. I know this is not an accurate comparison, but I did expect better times. I guess being above 5000ft takes more hp away than I thought.
I think it's time for more major mods to make a real difference. I can say that all my small mods combined reduced my et about 4 tenths over stock.
I think it's time for more major mods to make a real difference. I can say that all my small mods combined reduced my et about 4 tenths over stock.
Is it just me or should you be runnin at least half a second faster than that .....it was an automatic but in 01 my bro had a ram air and ran a 13.0 on street tires with an exhaust and tune.
So I'm considering buying one of these but it recommends 4 different belts. The last 2 appear to be the same exept for the price but the first 2 I'm guessing the ones for the A/C are different. Ones 37 and the others 40 which one do we need? And what the difference between the last 2?
So I'm considering buying one of these but it recommends 4 different belts. The last 2 appear to be the same exept for the price but the first 2 I'm guessing the ones for the A/C are different. Ones 37 and the others 40 which one do we need? And what the difference between the last 2?
The other 2 belts that come up in the required parts are for the GTO i believe......
Based on:
Temp: 72.7°
Humidity: 63%
Track Altitude: 5300 feet
Pressure: 29.91 in.
Density Altitude = 7634 feet ET
Uncorrected 14.12 @ 100.4 MPH
Corrected 12.55 @ 111.58 MPH