Anyone know how to fix RPM not dropping?
 

I have a new 2012 tC with a manual transmission. When I shift gears, the RPMs do not drop right away like other manual transmission cars I have owned. The dealer line on this is because the car has 6 gears, the RPMs are designed not to drop quickly. Sounds like #@&% to me. I suspect some kind of EPA emissions rule is being enforced.

Does anyone know what needs to be changed/replaced/adjusted to resolve this so the car drives like other manual transmission cars?

Thanks!

i guess it just has a heavier flywheel. Try upgrading the clutch and flywheel to a lighter one?

That's lag from the electronic throttle control. There is no throttle cable on this car. Sprint Booster and other throttle controllers reduces the lag. They are expensive though most owner's are very happy with the improvement over stock. Sit in your car with it in neutral and the parking brake on, engine running. Watch your tachometer and step on the gas pedal. The lag is so bad I can step on the gas pedal and remove my foot before the tach needle even goes up.

Thanks for your insight. That make a lot of sense. I'll check out the throttle controller solutions and see if they fit into my budget. TomCat

Update - I checked out the SprintBooster website. For less than $300, considering how anoying the RPM staying high is, not to mention the throttle lag you pointed out, I think it's a good investment and will definitely be ordering one. A no-hassle 30-day money back guarantee makes it a real easy decision. Thanks again for your shared wisdom.

Second update - I spoke with a tech at SprintBooster. He said their product doesn't affect the RPMs not dropping, that this is likely a function of the ECU. He added that no one else he knew of had a problem with the RPMs staying constant during shifting. Maybe I am just old skool..... It reminds me of a stcky throttle cable on an old British car.

That said, does anyone know of a chip or other approach to the ECU that may fix my problem without voiding the warranty?

Oldskool TomCat

upgrade to a lighter flywheel,that what makes the rpm respond and drop quicker,that sprint booster will only be good to take away the lag in the throttle ans make it respond quicker,if you you look at the tc1 diy section,theres a thread where you can take out the dead spot on the throttle if you have one,i know the tc1 had it,bascially will little mods here and there,youll enjoy the car alot more....i know i myself did all this and i have no throttle lag,instant response....i guess drive by wire isnt bad afterall

All newer cars run dbw and it does make for some annoyance sometimes. It made for a pita on ecu mods for my 06si

@ Tom, I don't own the Sprintbooster so I can't give you first hand knowledge. The original thread for it in the 2g forums had an owner reporting it did fix the rev hang.
https://www.scionlife.com/forums/sho...=Sprintbooster
I have seen a few other owners here and there state it improved the condition.
The lighter flywheel is another way to go, sound theory for improving throttle response and reducing drivetrain weight. I just do not see replacing these types of items on a brand new car.
To me it sounds like a no-brainer that if the Sprintbooster speeds up throttle inputs, all aspects should speed up. I'm no engineer but I have been under the hood of cars my entire life. Throttle cabled engines do not produce these lag issues, only dbw does.
Almost every Tc2 owner on this forum has noticed the lag issues, the Sprintbooster guys gave up on this forum a while back because 90% of us are not willing to pay that high price tag.

Sprint Booster
 

Hey Blackedout011TC -

Thanks for your thoughts. I am thinking that the RPM hanging is likely a combination of a lead flywheel and ECU management issues. I agree with you that replacing the flywheel on a new car is a drastic measure, and would likely give Toyota all the ammo they need to void any engine-related warranty claims as well.

I did order the Sprint Booster earlier this week. Even if it does not help with the RPM hang (and I hope that it does), it will get rid of the throttle lag which has been causing me to occasionally spin the clutch to make sure there is enough gas not to stall the car when starting from a dead stop. I have been driving manual transmissions my entire life, and this situation makes me feel like a complete tool. The $350 I spent will save wear and tear on the clutch at the very least.

I will post by observations on the results the Sprint Booster provides after I get it installed and test it.

The clutch and lag issues you will get used to over time. I got back in my old car after I gave it to a family member a year ago. Everything in it felt cheap and weird. I used to love driving it. I am really interested in your thoughts on the Sprintbooster for sure, keep us updated.

I think it's unlikely that the SprintBooster will address the rev hang that we're referring to here. I'm not talking about throttle lag, which is a different thing entirely. Yes it could assist with throttle lag, but will it do anything to rev hang? I've done as much research on this as anybody, and I think anyone who says the SB address rev hang, probably doesn't have the term defined correctly, and is confusing it with a different concept -- throttle lag.

It sure is difficult finding this out, since it seems all the coherent, truly knowledgeable folk, don't buy it, and thus can't offer any feedback with sample size > 1.

i have a weapon r throttle controller off a friend but i hear its like $149..i have a manual too and it fixed all those lag issues and its sad because the difference is night and day and not to mention it makes the engine sound so much better when on power mode.. It makes driving a scion alot more fun!

Your point is completely understood. When I posed the original question I intended the issue to be rev hanging, which as you point out is completely separate to throttle lag. I am skeptical that the Sprint Booster will improve the rev hang issue. I was willing to invest in in it just for throttle lag improvement alone. There is one way to find out. I will definitely post my sample of 1 opinion once I get it installed. It was shipped today, so it should be up and running next week.

Oddly enough, I installed an AEM CAI last week, and that seems to have mildly improved the rev hanging. This makes no obvious sense, but it does seem to have made things better. Go figure. I'm not complaining.

Looking forward to your feedback TomCat. You understand the nuance involved -- I sure hope it reduces rev hang appreciably.

any update??

I just received the Sprint Booster a few days ago. It's going in tomorrow, so I will share my thoughts after taking it for a drive. TomCat

O.K. - I have the Sprint Booster installed. It has made a huge difference in the throttle lag and my car now drives like a "normal" car. No more spinning the clutch or stalling the car based on unpredictable throttle response. There are two settings (besides "off"). The Sport setting works great, and is where I will leave things. The Race setting is very unpredicatble and the car seems to lunge without throttle pressure. I'm not impressed by this setting, but I'm O.K. with the investment, as the Sport setting has met my expectations.

Now for the $64,000 question - the Sprint Booster has not improved the rev hang that was my original concern when posting this thread. It appears that either the ECU or a 100 pound flywheel is likely the cause of this problem.

For those looking to make their car more fun and predictable to drive (by eliminating throttle lag) the Sprint Booster is still a good investment as I see it.

I guess I'm just going to have to learn to live with the rev hang. :-O

Update to previous post -

After letting the car sit overnight, the erratic performance with the Red setting on the Sprint Booster appears to have gone away. I am now finding the higher sensitivity of the throttle in the Red setting even more likeable than the Green (Sport) setting. TomCat

Thank you for your thorough feedback, TomCat.

After a few months the rev hang will not bother you as much. I stalled mine out quite a bit in the first two months of ownership, got used to it. Your brain eventually compensates. I was hoping the SB would at least reduce it some. Thanks for the info.

Cool - glad you found it helpful. TomCat

I haven't managed to get used to rev hang. It still annoys me to no end, and truly robs the car of useful performance and wears the clutch out more quickly. For someone who's become decent with a clutch and enjoys concise, efficient driving, this is a real issue. For a novice or perhaps an experienced yet very patient, no-particular-place-to-go driver, the rev hang is actually kinda nice. It's unfortunate that this has to be a one-size-fits-all parameter. I can't really blame anybody else except myself, however. After all, I decided to purchase the car after test-driving it! In defense of that mistake, it was my first manual transmission vehicle, and I've learned a lot in the past couple years. My next vehicle will also likely be so-equipped, and I'll be armed with more experience.