Have about 1200 miles on my STi now, on my previous car, an '03 SRT-4, the staged upgrades actually promoted WOT shifting by making it backfire at the time you are WOT shifting to keep boost up as you bang the next gear. My question is: is the tranny and clutch strong enough for this kind of abuse?

So if I understand correctly, you are asking if you can shift without lifting off the throttle at WOT?

I imagine what will happen is that a fraction of a second after you depress the clutch, you'll be banging right off the rev limiter. Depending at what RPM you shift, you may be less likely to damage anything. Thus if you shift at 6800 RPM, you don't have far to go till you hit rev limiter, and thus there won't be that large of a difference between engine and tranny when you re-engage the clutch.

I'd say it can probably handle it, but it certainly isn't good for it.

If you roll of the throttle, shift, then roll back on, you should be fine and your shifts will be much smoother.

-Michael

...on my previous car, an '03 SRT-4, the staged upgrades actually promoted WOT shifting by making it backfire at the time you are WOT shifting to keep boost up as you bang the next gear. ...

that is the funniest thing i've read in weeks.

rev-limter as als...

:lol:

that is the funniest thing i've read in weeks.

rev-limter as als...

:lol:
To quote Mopar.com:
Boost hold feature during WOT shifts. Keep the pedal to the metal, blip the clutch, and grab the next gear. Do it fast enough before the redline, and your reward will be a zero-lag, constant boost shift.


What part of that is funny?

the whole thing.

i find it hilarious that mopar.com is calling this a "boost hold feature." :lol:

flat foot shifting without a two-step?

whatever floats your boat man!

where's the part from mopar about an afterfire keeping the boost up? i missed it.

Well, the actual explanation is in the install manual from the staged upgrades.

ok, enough ridicule... seriously, to answer your question, yes, you can flat-foot shift the sti. others have done it and their cars seem to hold up just fine. sinister (or is it sinistir?) flat-footed his way to a 12.4 @ ~110mph with a turboback, intake, and utec, iirc. EDIT: i don't know the conditions of that run--since he has a utec he very well might have turned on flat-foot-shifting (aka launch control, aka secondary rev-limiter, aka two-step) which the utec offers.

realize that something has to give. hopefully it is your clutch, which can be helped by slowing your left foot down slightly... slip it for a fraction of a second. if it isn't the clutch, then the entire drivetrain (gearbox, diffs, engine, cv joints, etc) will take up the shockload as the clutch rpms suddenly match the flywheel rpms.

it is for all these reasons that the first "two-step" rev-limiter was installed. this allows one to induce a secondary, lower rev-limiter for the period of time that the shift is occuring. it can be triggered with either the shifter (ie, neutral sense) or the clutch pedal (more common). configured properly, you can pop the clutch out just as fast as you'd like and there is NO shockload to the drivetrain as the power is reapplied, since the rpms of both drivetrain and engine will be perfectly matched.

in other words, sure you can do it, sure some people have, but it is a much more risky method of shifting your car than to do it "properly," which is to say letting the engine rpms drop accordingly (either manually or with a two-step) before the clutch is let out again.

jm2c
ken

"power shifting" is what I know this as from dealing with my honda roots, and yes you can do it in an sti. I however do not suggest it in a 02 (personal view, prob 03 as well) wrx because of the synchro's, if i am not mistaken the sti's and newer wrx's have dual coned synchro's. I had a hard time with doing it well enough to call it safe in a 1st to 2nd change. I would also only do this in a serious race and not on a daily occasion because of the potential long term wear it has on the drivetrain. so pretty much what ride said (sorry didnt read that much into your post)!

I do not suggest doing that. fifth gear has only one synchro. I blew mine out after 3500 miles. I only started getting on it after 3300.

Power shifting, as I know it is actually clutchless, not keeping the hammer down. I learned this from dirt bikes, you lightly lift off of the gas and click into the next gear; it only works well at upper RPMs. You need exceptionally short shift throw, as on a bike to pull it off; quite fun on an Integra if you can get the hang of it. I've never tried it with my Suby. Wait, that's speed-shifting. I don't think I ever heard of power shifting. Well, I'll leave the post anyway. Anyone brave enough to try speed shifiting one of our beasts? The tranny doesn't feel strong enough to me, I'm not guinea pigging it. . . I gotta drive the thing till it's paid for. My integra was a b-e-a-t-e-r!!

My g/f did your "speed-shifting" on my old civic when she was racing, ON ACCIDENT! the nasty noise i heard from that makes me cringe just thinking of doing it on our weak ass tranny.

I've heard of the srt-4s doing it, but not too many subies. Better safe than sorry!

I've heard of the srt-4s doing it, but not too many subies. Better safe than sorry!
Yeah, my SRT-4 had a bullit proof tranny, and from what I read the 6 speed in the STi is just as strong, but I guess I wont do it, you just never know. Still, its odd to hear a company endorsing it, like Mopar did....

Boost hold isn't really true. Sure it helps as to keep the engine rpms up. But as soon as load is removed from the engine so is boost, hence why when you rev up your car in neutral you dont really make boost. Just thought i'd share. Not trying to rag on anyone. Well maybe mopar a little. lol

Boost hold isn't really true. Sure it helps as to keep the engine rpms up. But as soon as load is removed from the engine so is boost, hence why when you rev up your car in neutral you dont really make boost. Just thought i'd share. Not trying to rag on anyone. Well maybe mopar a little. lol

this is not necessarily true--the load is presented by the inertia of the engine's moving parts.

i can sit with the clutch and the gas both on the floor and get over a bar of manifold pressure without the car moving at all.

viva launch control! :devil:

jm2c
ken

I think what Mopar is trying to say is that you can use the rev limiter as some kind of makeshift anti-lag system. Anti-lag works be retarding the spark so that the fuel leaves the combustion chamber and detonates in the exhaust producing gas to keep the turbo spooled. When you hit the rev limiter in this SRT-4 or whatever it may be, the computer must retard the spark thereby doing the same thing is anti-lag.

Bryan

I'm not positive that this is true for every car, but I think on most cars a rev limiter is another word for a fuel cut off. It doesn't change the timing, but instead changes the pulse on the injectors to only allow half the fuel in. Hence the noise (ba ba ba ba ba)

Sure MOPAR can promote that, they know the Neon lacks the torque of an STi :lol: :lol: :lol: Turn the A/C on and feel it drag... :lol:

I feel that the A/C causes the wrx to lose more power than the SRT-4. I dont know about the STi seeing as how I haven't driven one.

The STi is AWD. The Mopar is not. Wheels can slip on the mopar. The wheels are less likley to slip in an AWD car. I assume this is much harder on the AWD platform. Especially on tarmac with sticky tires. If the tranny breaks, it is a trip to Japan for it as I believe they are not serviced in the states yet. I realize you'll go to the dealer and cry foul and expect them to fix it. Good luck with that.

May I recomend a 68 Camaro with a Transmition Specialties gear box.

Sure MOPAR can promote that, they know the Neon lacks the torque of an STi :lol: :lol: :lol: Turn the A/C on and feel it drag... :lol:

The staged MOPAR upgrades can put the SRT-4 at or above STi power levels at the crank and even more to the wheels. Get a clue.... please.