Planning on supercharging my 9th gen, what’s the rough tq/hp limit on the stock trans?

linuxguy192

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I’m sure this has been posted before, but I can’t seem to find it. Find people talking about everything but what power numbers I would need to start upgrading gears at. I would like to put the KW supercharger kit on and aim for 300-330whp. I am at high altitude so that number may be slightly lower. I want to build a reliable daily, and supercharger seems to be the choice for that over a turbo. I see people with turbos talk about upgrading gears 3-4 because they shred, but always seem to replace them after they break. I would like to be proactive and do everything right the first time.

thank you!!
 

squiggy

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I’m sure this has been posted before, but I can’t seem to find it. Find people talking about everything but what power numbers I would need to start upgrading gears at. I would like to put the KW supercharger kit on and aim for 300-330whp. I am at high altitude so that number may be slightly lower. I want to build a reliable daily, and supercharger seems to be the choice for that over a turbo. I see people with turbos talk about upgrading gears 3-4 because they shred, but always seem to replace them after they break. I would like to be proactive and do everything right the first time.

thank you!!
Around 350whp is where people start breaking 3rd gear.
 

webby

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I actually don’t think I’ve seen anyone below 400hp have a gear go. It was usually 4th gear on hard pulls with turbo setups. You shouldn’t have to do anything to your trans with what you’re wanting to do.
 

squiggy

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I actually don’t think I’ve seen anyone below 400hp have a gear go. It was usually 4th gear on hard pulls with turbo setups. You shouldn’t have to do anything to your trans with what you’re wanting to do.
For some reason, 350 sticks in my head for when I was planning on the SC install.
 

webby

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For some reason, 350 sticks in my head for when I was planning on the SC install.
People tended to say 325-350 was pushing the limit to the stock clutch? I know people have gone above that on the stock clutch, but it tends to slip.
 

freggie

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turbos can kill trans because after the boost threshold sometimes the boost comes on hard and strong and this sudden jolt is what breaks things, feels great and can make skid marks in pants but you can feel the powwaaa then it goes away at high rpms. This is why its better to go bigger slower spooling turbo than a small faster spooling turbo. You just don't get that kick with big turbos, but power delivery is more linear like superchargers.
 

Bruce Bartlow

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I am nowhere near the Ring, otherwise the C8 would be a tempting test drive. Outside the Ring, a CTR checks a lot of boxes
For some reason, 350 sticks in my head for when I was planning on the SC install.
If someone wants to be "proactive" (i.e,. not surprised by a sudden failure) 350 might be the better guide. Of course, all depends on how hard he pushes whatever HP he has.
 
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