Manual Gearbox Question?

justpete · 03-25-2016, 09:07 PM

Quote:

Originally Posted by sparky_phantom

I am running Cobb right now. It did it when it was stock. I now have the PPK Flash and Cobb. And yes it just hangs there before dropping. Doesn't drop instantly at all.

Thought the throttle should do that on a turbo engine to keep boost up instead of letting it drop out during the shift? Wouldn't affect shift time though, right?

sparky_phantom · 03-25-2016, 09:12 PM

Quote:

Originally Posted by justpete

Thought the throttle should do that on a turbo engine to keep boost up instead of letting it drop out during the shift? Wouldn't affect shift time though, right?

2nd gear it affects. I can't go fast or remotely fast in 2nd or it will drop so much rpms that it because rough. I assume because of the long ratio of 2nd gear. However if I wait a second or two then engage clutch it doesn't do that. But I don't believe I should have to wait a few seconds just to get to 2nd. 3rd gear is somewhat like that, but not nearly as bad.

justpete · 03-25-2016, 09:17 PM

Quote:

Originally Posted by sparky_phantom

2nd gear it affects. I can't go fast or remotely fast in 2nd or it will drop so much rpms that it because rough. I assume because of the long ratio of 2nd gear. However if I wait a second or two then engage clutch it doesn't do that. But I don't believe I should have to wait a few seconds just to get to 2nd. 3rd gear is somewhat like that, but not nearly as bad.

So you're saying the revs hanging causes an abrupt upshift when you re-engage the clutch? If the revs would drop then you could get a smoother shift due to rev matching, more or less?

sparky_phantom · 03-25-2016, 09:19 PM

Quote:

Originally Posted by justpete

So you're saying the revs hanging causes an abrupt upshift when you re-engage the clutch? If the revs would drop then you could get a smoother shift due to rev matching, more or less?

More or less yes. That is what is happening.

justpete · 03-25-2016, 09:20 PM

Quote:

Originally Posted by sparky_phantom

More or less yes. That is what is happening.

How much clutch slip do you get if you powershift through it? Or do the tires chirp instead, or also, I guess?

sparky_phantom · 03-25-2016, 09:24 PM

Quote:

Originally Posted by justpete

How much clutch slip do you get if you powershift through it? Or do the tires chirp instead, or also, I guess?

Not sure exactly what slipping feels like. First manual. Power shifting I assume you mean just shifting very quick. If I get to the high rpms then yes tires will chirp or spin slightly.

justpete · 03-25-2016, 09:27 PM

Quote:

Originally Posted by sparky_phantom

Not sure exactly what slipping feels like. First manual. Power shifting I assume you mean just shifting very quick. If I get to the high rpms then yes tires will chirp or spin slightly.

That actually sounds normal. Slipping feels like the revs don't change instantly when you engage the clutch but instead spin down quickly, not the best description. If the tires chirp or spin the rev mismatch is being shared between the clutch and the tires slipping, mostly the latter.

sparky_phantom · 03-25-2016, 09:30 PM

Quote:

Originally Posted by justpete

That actually sounds normal. Slipping feels like the revs don't change instantly when you engage the clutch but instead spin down quickly, not the best description. If the tires chirp or spin the rev mismatch is being shared between the clutch and the tires slipping, mostly the latter.

I thought rev match I only really needed to do on down shifts?

justpete · 03-25-2016, 09:44 PM

Quote:

Originally Posted by sparky_phantom

I thought rev match I only really needed to do on down shifts?

Technically. If the throttle didn't hang when you lifted the revs will drop and if you're quick enough the next gear up will engage at or near the right rpm making for a much smoother upshift.

sparky_phantom · 03-25-2016, 09:47 PM

Quote:

Originally Posted by justpete

Technically. If the throttle didn't hang when you lifted the revs will drop and if you're quick enough the next gear up will engage at or near the right rpm making for a much smoother upshift.

That makes sense just rpms don't drop quick enough for that. They stay before dropping even with clutch all the way to the floor.

justpete · 03-25-2016, 09:48 PM

Quote:

Originally Posted by sparky_phantom

That makes sense just rpms don't drop quick enough for that. They stay before dropping even with clutch all the way to the floor.

Maybe you can get the tune modified to make the revs drop faster?

sparky_phantom · 03-25-2016, 09:49 PM

Quote:

Originally Posted by justpete

Maybe you can get the tune modified to make the revs drop faster?

Maybe, is that a tuneable thing? Why does it do it with stock tune too?

justpete · 03-25-2016, 09:51 PM

Quote:

Originally Posted by sparky_phantom

Maybe, is that a tuneable thing? Why does it do it with stock tune too?

Should be, it is for an NA engine with Valvetronic and is in fact faster than stock with an AA tune. Not sure if you have a Valvetronic engine though, sorry.

sparky_phantom · 03-25-2016, 09:52 PM

Quote:

Originally Posted by justpete

Should be, it is for an NA engine with Valvetronic and is in fact faster than stock with an AA tune. Not sure if you have a Valvetronic engine though, sorry.

Should have valvetronic with the N55.

justpete · 03-25-2016, 09:54 PM

Quote:

Originally Posted by sparky_phantom

Should have valvetronic with the N55.

Thanks. Should be something that can be changed then. If it drops too fast then slow shifting can dog the engine a bit around town unless you blip the throttle on upshifts, too.

sparky_phantom · 03-25-2016, 09:56 PM

Quote:

Originally Posted by justpete

Thanks. Should be something that can be changed then. If it drops too fast then slow shifting can dog the engine a bit around town unless you blip the throttle on upshifts, too.

I wish it would drop faster would make shifter easier for 2nd and 3rd lol.