Ways for faster revving when blipping the throttle??
 

I am not sure if this is the parasitic loss due to supercharger but I could definitely notice the slower revving feel during the down shift rev matching since the clutch pedal is depressed during the down shift rev matching all I think of is the lighter crank pulley or maybe an underdrive pulley?



Any other suggestions?

It's a very critical safety issue in my opinion and surprisingly I couldn't find anyone mentioned it here

Lightweight clutch?

I know what you mean. I immediately felt the same thing after my Innovate SC kit was installed. The slow revs that I got when trying to blip the throttle on a downshift reminded me of when I first purchased my car and the engine hadn't broken in yet. My first thoughts were to get a set of lightweight pulleys and a lightweight flywheel. I'm going to hold off on the pulley set for a while, but I definitely want to switch to a lighter flywheel.

^^^^

That

You'd want a light weight flywheel...the clutch has nothing to do with the rotation of the crank when you are rev matching.

I'm not sure how light flywheel/clutch combo can help when clutch pedal is depressed simply because there is no pressure on them ..I can understand when on the gear iit should definitely help the engine revs freely ..I think same can be said for the drive shaft too..so the only thing one my mind is the lighter pulleys or other methods that reduce the parasitic load/loss.. I don't have any experience with underdrive pulleys or lighter pulleys..

You'd want a very light flywheel, i have a 10.5 pound one and my revs jump to over 3 with slight blips


[ame="https://www.youtube.com/watch?v=A_1c8bcudag"]The joy of a 10.5 pound flywheel - Turbo Frs - YouTube[/ame]

That's what I thought, how can the lightweight flywheel affect the engine speed when clutch is not engaged ? I always thought it would be the same with lighter clutch..

The bad thing is since Kraftwerks kit uses a unique crank hub adapter that goes over the OEM pulley so I'm not sure if I can use an aftermarket one.. One of the owners had his kit installed by a shop but I think it's modified

Thanks for the video, I wonder how it would rev with a SC since the load on the belt should be one of the main factors for slow revving..

The flywheel is on the engine side of things, so even if the clutch is disengaged the flywheel is still spinning. The OEM flywheel is heavy by design. This creates significant inertia once it's spinning, so if you're less than smooth with the clutch it doesn't bog the engine. The downside is that there's more weight to spin and more inertia to overcome when you want to change engine speed. Blipping the throttle on a downshift, say.

A lighter flywheel is better in some ways, as there is less rotational mass and less inertia to overcome when changing engine speed, but at the same time it's less tolerant to marginal shift technique because there is less inertia. Some manufacturers (Exedy, I think) will lighten the flywheel while trying to keep most of the remaining weight around the outside of the wheel. This helps to maintain the spinning inertia, while still removing weight and rotational mass.

Well, It's not my technique ;) but thanks for the lesson

If that's the case I think my only option is to change the flywheel (most likely with an Exedy Stage 1kit)
I actually knew the disadvantages of lighter flywheel but just didn't know it would still help the faster revving when clutch is disengaged.
Thanks again

BTW, I also ordered Cusco accelerator pedal so maybe it may help a little bit..ugh

Stiffer motor mounts would probably help too. Less slack under load. More NVH though...

Oh gawd:confused0068:

LFA..jk haha.

As fast as one, but has a stick :) lol


Sent from my IBrick

Another thought: with a lighter flywheel, the engine will rev faster, but the revs will drop off quicker as well, so you have to be quick with your downshifts.

Yes it does. What is the clutch pressure plate attached to? The flywheel. That means that the pressure plate is always spinning and has an effect on the rotational inertia of the engine.

Not really true.

The clutch "disk" has nothing to do with it when the clutch is depressed because that part is attached to the transmission input shaft.
However that disk is a small fraction of the mass of the entire clutch.

The heavier part is the pressure plate which is attached to the flywheel and makes a HUGE difference to the overall mass of the rotating assembly.

By getting a lightened flywheel and a lighter pressure plate, you will see a huge difference in rev up/down.

Easy. Light flywheel, low inertia clutch kit, and tune that throttle positioning. ;)

If you want better response, full blue printed motor, titanium transmission gears, ultra lightweight driveshaft and half shafts. :)

Small problem though, I don't have deep sockets :D if I did I would possibly never consider a SC but instead go with full motor/race engine specs ..even if I didn't have the SC power..

BTW, how is the throttle positioning affect the revving speed when clutch depressed ? I asked my tuner to send me a more aggressive throttle mapping and with that I can clearly notice the responsiveness when in gear but couldn't difference any change when clutch is depressed

I have no problem with being quick on my downshifts ;)

But yes, I know the side effects of lighter flywheel ..with that said being able to rev match is a lot more important and it's very critical at the track if you really push your car with SC

Our cars are completely numb when revving from idle. I don't know whether it's the drive by wire or the tune, but they rev very slowly. I suspect it is the tune mainly.

When my car is warming up, the throttle response is great, super snappy, but when fully warmed up it goes back to sluggish.

My tuner made some changes that improved the throttle response as well, so I know the throttle response can be improved at least in part by the tune.

Of course, lightening the rotating parts (flywheel, clutch, driveshaft) will help with throttle response, but the main issue lies more within the tune, or the type of induction IMO.

My old race car with carbs had insane throttle response. I saw other cars with the same engine, but fuel injected, that had much slower throttle response.

I think fuel injection gives less of a shot of fuel with throttle movements. Carbs have accellerator pumps. I think fuel injection basically does the same thing (a shot of fuel to get things up and running) but the throttle response is still very sluggish on our cars, especially with such high compression.

From experience, you don't want instantaneous quick response on the throttle with direct injection lol. That will be deep pocket territory too. ;)

I am guessing here, so go easy on me:

The ROM has two tables called "Requested Torque A (Accelerator Pedal)" and a "B" version.

The values in the table indicate "driver requested torque based on accelerator pedal angle and engine speed. This value is used to determine the target throttle position"

The two tables A&B have vastly different values in them.
Table A has much larger values than table B.

Here's my guess: Table A is probably used when the ECU determines if the driver is accelerating and table B if decelerating.
(I am probably wrong).

But it seems that adjusting the values in Table B might give you a faster spin down.

Maybe @moto-mike can chime in share his thoughts with us on that :)

:) nope we don't want that so I think the safest way to improve that is changing the clutch/flywheel combo with a lighter alternative ..

Has anyone adjusted the gas pedal I wanna see if the Cusco pedal helps a bit and maybe raising the pedal a bit (if possible of course) but then again all these methods don't really address the main issuw they seem like just temporary fixes/patches

Partially true on my part ;] I stand corrected!

Im gonna pipe in a can of starter fluid to my intake track.
Once I figure out how to connect the nozzle to my throttle, I should have nice blippz!

Is there a significant and noticeable benefit to the lightweight driveshaft for a dd/track car without the draw backs in daily driving of a lightweight flywheel? How do the two compare? My Cayman is very responsive due to the light flywheel and throttle programming, but at the same time, very difficult to not stall, especially on hills. Also, what are the practical pros/cons of an aluminum vs CF driveshaft, if it is a noticeable bang for your buck improvement?

Lightweight driveshaft will feel different compared to the lightweight flywheel. The reason is quite simple. The light flywheel is going to require you to be a little more in tune with your car which requires you to have good reflexes when engaging the throttle and clutch in a coordinated fashion. Everything happens "quicker" with a light flywheel. The light driveshaft just lowers rotational inertia of the drivetrain as a whole. Yes it does make it better, but it's not lightyears away different. The response, of course, will be much improved over stock. How much is seriously based on user experience and preference. For reference, I daily drive on a 8lb flywheel in my personal car. I have absolutely no issues driving on 7 degree inclines or more. :)

CF is going to be a stronger setup. I wouldn't think there is a huge difference between the CF and the aluminum versions. Our tuning philosophy has always been doing things right the first time around. Obviously, not everybody is willing to go down that route as well so we have provided solutions that fit specific budgets and goals. :)

I see someone's never played any of the gran turismo series.


with the clutch disengaged the flywheel becomes one of the heaviest component that an engine must accelerate (the others being the crank and the combined weight of the 4 pistons), reduce it's weight and you reduce the speed at which the engine will rev up


the downside to this is that it also revs down quicker as well, which requires more finesse in engaging the clutch

I actually knew the downsides of the lighweight clutch and flywheel but I didn't know that the flywheel also helps even when the clutch is disengaged which answered earlier..

I am surprised that nobody with SC kit mentioned this important detail, it's very very hard to heel toe with the current setup even after the Cusco accelerator pedal...gas pedal just feels so numb.. then again, this is my first SC car

You don't want to go too light on an FI car in general. It gets kind of annoying unless you want a higher idle...racecar status brah.

IMO, it makes it easier to dump the clutch without drivetrain shock... as long as you learn to time it.

My light flywheel is one of my favorite mods on my s2k.

oh I don't care about the racecar status :) and would never consider getting a lightweight flywheel or clutch if it didn't cause a safety issue at track..

Well you are curious as to how you can bring up the response with the blip of the throttle. Actually the lightweight flywheel is probably the best mod for it on top of tune. I ran an 8lb flywheel with a SC setup in the S2000 before. It was great, but the idle had to be brought up 200 RPMs to smooth it out. The car revved up perfectly for my use, but everybody else found it too quick. ;)

There may or may not be a 5.5" twin disk in the works.

:popcorn: