Shift Points

[REDBLUR]

What RPM's do you guys shift at on the track and for daily driving?? Also what about downshifting, do all of you do it?

Just bored and curious!!

 

[gstspyder1998]

Originally posted by REDBLUR
What RPM's do you guys shift at on the track and for daily driving?? Also what about downshifting, do all of you do it?

Just bored and curious!!

When I race somebody on the streets I shift at redline and when I'm driving normal I usually shift at 4k. Oh and I also down shift!!!

 

[larryd]

im usually at redline when running and around 5-6 when normally driving.. Ive heard though that I might get better times if I shift at 6500 instead of 7500

 

[2GTsiAWD]

Depends on the MODS....If you have a Tiny-25 6000 to 6300 is best. If you have a 16G or bigger you could go higher, but think about what cams you have. Are they working up there or are they just flopping the valves open and closed...There are many other factors too. Timing( are you getting any detonation?), Fuel Volume...Is the fuel pump keeping up? These are all to be considered.

 

[jdmawd]

the only way to really know, is to put the car on a dyno. that way you find where power starts to drop off. that is where you want to shift. if your car peaks at 6500, you are hurting your self by shifting at any higher.

 

[GRNDSM]

That is a pretty complicated question. It all depends on your mods. If you still have a 14b, you want to take the first gear all the way to the rev limiter (as close to 7500 as you can with out hitting it). The rest of the shift should be made at 7000-7200.

With the 16g you can go much higher. I have been running as close to my TMO 8k rev limiter as possible (again with out hitting it).

And it is not as simple as not going beyond your peak HP. Lower gears give you higher mechanical advantage and it might me useful to stick it out in a gear a bit longer. You also do not want to get in to the next gear too early because it can take our of the power band due to RPM drop (this is more likely with a larger turbo).

You can look at the slope of RPM curve on a dataloger and judge it by it. If you see it starting to flatten out, it is time to shift.

 

[4Banger]

That's true, your car will accelerate faster on a lower gear with the same horsepower, so it's better shift after your power curve begins to drop, and that will put you closer to your power peak on the next gear. I usually shift at 7750.

 

[kylemoto]

To really know when to shift, you need to get a torque/HP versus RPM chart from a dyno shop. Using this you can really know when is the best time to upshift.

Assuming you have a 14B equipped first Generation DSM with stock cams, there have been several dyno plots punlished. These plots show before and after changes of using different exhausts, downpipes, etc. Yeah, its not exact, but you can certainly see some characteristics that we can use. The ones I have seen all seem to have the power peak between 5500 and 5800 rpm. The HP curve is not bell shaped, it is asymetrical, with more power on the low rpm side of the curve. This would indicate that a 1-2 shift might be best placed at 6500 to 6800 rpm, with a 2-3 shift at 6200 rpm, and a 3-4 shift at 5800. Sounds low, I know, but remember this is a near stock engine. Other mods (bigger turbo, cams, etc.) would certainly change power curves and shift points.

Have fun

Kyle

 

[2-0turbo]

Seems like everyone has pretty much summed this one up. Basically, depends on your car and mods. When I was completely stock, you could really feel the power drop off past 5500. Running the engine to higher RPM's just seems to make more noise. Now with a 3" catback, it pulls pretty good to 6500, but you can start to feel the power fall off up top.

In my profile, the only time I have been to the track is with that single 1/8th mile run. That was tough because with stock exhaust, the 14B really runs out of steam past 5K or so. So, the best time I could manage in the 1/8th mile is to extend second gear past 7K. If I shifted to 3rd gear, my times were slower.

I really need to head to the track at some point. That was a hot summer day and bone-stock. I've done a few mods since then. The only other number I have is a 96 MPH trap via G'tech in the quarter mile. I REALLY can't wait to get that ETE32 installed! I expect that to still be pulling very STRONGLY at 7K, even on stock cams. Look out with fatter cams...I just might rev it to 8K.