dpuma8 Posted October 19, 2010 Share Posted October 19, 2010 I have a 280Z with a L28et swap in it and the gas pedal is ridiculously sensitive and I can't get used to it. I get stress knots in my neck from driving in stop and go situations. It is just way too sensitive. Is there a way to adjust gas pedal sensitivity to make the car more drivable? Quote Link to comment Share on other sites More sharing options...
blue72 Posted October 19, 2010 Share Posted October 19, 2010 This one is meant for the 240Zs but I'm hoping perhaps that it might help. http://www.zhome.com/ZCMnL/tech/AcclLinkage.jpg Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted October 20, 2010 Share Posted October 20, 2010 Does it have an aftermarket throttle body? Quote Link to comment Share on other sites More sharing options...
hoov100 Posted October 20, 2010 Share Posted October 20, 2010 Sounds like you are using to much throttle when you let the clutch out, or you are letting the clutch out to fast and not slipping it. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 20, 2010 Share Posted October 20, 2010 Driver error, refine technique. Otherwise, bellcrank pivot arcs will do a lot to change the linearity of the movement. But generally, with a stock clutch plate (you did not specify metallic clutch) this is a driver finesse issue with brickfooted throttle and clutch usage. My turbo car had throttle cable actuation to triple 44mm carbs on a blowthrough turbo running a 9# flywheel and a metallic clutch running through a 3.7 rearend. I could drive it all day in LA stop - n - go. My wife HATED it because 'it had an on-off-switch throttle' and REFUSED to drive it. She could not master the pedal finesse. This is a driver issue, not an equipment one. Especially if you are on a stock rearend and organic clutch facing! Stock weight flywheel? DEFINATELY a driver throttle modulation clutch engagement learning curve issue!!! Turbos make torque even when not showing boost. It drives different than the old engine, get used to it. That's why the swap was done. If the throttle is STICKING (as they sometimes do) then fix that, but the linkages are the same on ET and any other EFI or Carbbed Datsun. It's just a matter of controlling your foot. Try driving in wrestling shoes and see if it's any better than CAT Workboots (seriously!) Quote Link to comment Share on other sites More sharing options...
ModernS30 Posted October 20, 2010 Share Posted October 20, 2010 If you really have an issue. Large spring should fix it. A spring that shows more resistance could help you not push the pedal so fast/easy. Honestly, that is how you adjust a pedal movement speed issue. If your driving a stick you should be able to overcome the issue. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 20, 2010 Share Posted October 20, 2010 No, increasing tension with a spring only masks a poor technique, and overstresses the linkages. The car ran fine without a spring from the factory it shouldn't need one now! A spring is a band-aid for poor technique, or a binding linkage someplace. Fix the problem not the symptom! There are tens of thousands of cars on the road like this that operate just fine without an additional spring. My triple setup had only the stock mikuini spring on the crossbar to return the linkages to stop. Many people were 'amazed' at how light the throttle pedal was---"Like a stock 240 with SU's!" Compared to many people with 40# of spring pressure to keep their throttles closed becuse of boudn linkages, linkages that were misadjusted, poor over-center design on their 'modified' bellcranks... In daily driving a HEAVY throttle pedal will become TIRESOME. Take if from me, you DON'T want a heavy throttle, when you get into a car with a properly designed silkysmooth throttle pedal you will continually brickfoot it and never get the hang of throttle modulation. A spring is not the answer, and it is 'NOT' how you adjust a pedal speed movement issue! Look at ANY OEM throttle setup and see how hard they work to NOT put additional springs on their setups. MECHANICAL LINKAGE that self-returns to idle WITHOUT SPRING AID (this does not include at the carburetor where a throttle return spring is mandatory) is the SAFEST setup there is. If the linkage breaks, the carbs will return to IDLE. If you depend on a SPRING to control the LINKAGE, if it breaks there is a chance the T/B will NOT go back to idle on it's own and you are up sheets creek without a paddle my friend. Properly engineer the solution, don't band-aid it! Quote Link to comment Share on other sites More sharing options...
ModernS30 Posted October 20, 2010 Share Posted October 20, 2010 No, increasing tension with a spring only masks a poor technique, and overstresses the linkages. The car ran fine without a spring from the factory it shouldn't need one now! A spring is a band-aid for poor technique, or a binding linkage someplace. Fix the problem not the symptom! There are tens of thousands of cars on the road like this that operate just fine without an additional spring. My triple setup had only the stock mikuini spring on the crossbar to return the linkages to stop. Many people were 'amazed' at how light the throttle pedal was---"Like a stock 240 with SU's!" Compared to many people with 40# of spring pressure to keep their throttles closed becuse of boudn linkages, linkages that were misadjusted, poor over-center design on their 'modified' bellcranks... In daily driving a HEAVY throttle pedal will become TIRESOME. Take if from me, you DON'T want a heavy throttle, when you get into a car with a properly designed silkysmooth throttle pedal you will continually brickfoot it and never get the hang of throttle modulation. A spring is not the answer, and it is 'NOT' how you adjust a pedal speed movement issue! Look at ANY OEM throttle setup and see how hard they work to NOT put additional springs on their setups. MECHANICAL LINKAGE that self-returns to idle WITHOUT SPRING AID (this does not include at the carburetor where a throttle return spring is mandatory) is the SAFEST setup there is. If the linkage breaks, the carbs will return to IDLE. If you depend on a SPRING to control the LINKAGE, if it breaks there is a chance the T/B will NOT go back to idle on it's own and you are up sheets creek without a paddle my friend. Properly engineer the solution, don't band-aid it! Fair enough. I cannot argue with greater knowledge. I was aware of the issue of the pedal tiring your foot for daily driving or long trips. Quote Link to comment Share on other sites More sharing options...
dpuma8 Posted October 20, 2010 Author Share Posted October 20, 2010 The car has an aftermarket clutch and as far as the throttle body, I am not sure if it is stock or not. Yes it is Driver Error and I am not saying it is equipment failure or anything, I just wanted to know if I could adjust something to make it more user friendly. So I take this as a 'no'? Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 20, 2010 Share Posted October 20, 2010 Adjusting the bellcrank angles, or any number of things. But that will compromise the geometry that is set up and works. Learn to modulate your foot, it will take less effort, you won't have to change it back later once you figure out how to drive it, and disciplining your foot will pay dividends in ANY car you drive from this point forward. If the clutch is metallic ('aftermarket' doesn't tell us much) there is really no way to get rid of a harsh engagement save for running more pucks. An 8 puck will be more smooth than a four. And a Four puck will be more smooth than a three. If you put a two puck ferro-metallic clutch in there, you better be running Paddla-Traks on the dunes someplace because it will literally be an on-off switch that will break your seatback when the thing gets traction! I had a 3 puck in a car some time ago, and it was 'race only' the only slippage I got was from the tires on wet grass! That was the only time the car moved smoothly too! Quote Link to comment Share on other sites More sharing options...
MoNkEyT88 Posted October 23, 2010 Share Posted October 23, 2010 My M3 has an electric throttle mode where it is more linear (aka feels more sensitive). I always use it, because I am just used to it. I was test driving a new Corvette Grand Sport and I killed it starting off. It really felt like I had to mash on the gas pedal to bring the revs up! I bet I looked like a newbie driver lol! I'd suggest just getting used to it, once you are, you'll never notice it.... until you drive something else lol.. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 23, 2010 Share Posted October 23, 2010 I have a 280Z with a L28et swap in it and the gas pedal is ridiculously sensitive and I can't get used to it. I get stress knots in my neck from driving in stop and go situations. It is just way too sensitive. Is there a way to adjust gas pedal sensitivity to make the car more drivable? Is it sensitive from mid-throttle on, or only from closed throttle on (what you might see in stop/go traffic). One is driver skill, the other might be a mechanical problem. My car recently (like last week) had the throttle plate sticking in the throttle body at closed throttle, I couldn't get the throttle moving again without it popping off the closed position and bucking forward a little. It would even hang open a little when it got really warm, raising the idle to 1500. I took the AFM boot off and cleaned out the "varnish" where the throttle plate sits in the bore with some Scothbrite and carb cleaner, plus honing out the bore a hair where the plate sits (Scothbrite will remove metal), to make up for wear on the set screw (the set screw lock nut is impossible to reach). Just another possibility. I am assuming the turbo throttle bodies are similar. Quote Link to comment Share on other sites More sharing options...
B00STDZ Posted October 23, 2010 Share Posted October 23, 2010 Just post a picture of your engine on the intake side... That should tell alot... Quote Link to comment Share on other sites More sharing options...
JayBee280 Posted October 31, 2010 Share Posted October 31, 2010 HAHA this post is funny...this guy only needs a simple answer. Here it is. Go to your local auto parts store ask for throttle body return spring. I had this same problem the gas pedal was extremly sensitive(sometimes hovering idle) this is not driver error. Its simply to sensitive for certain drivers and the way they like to drive. I even go better gas mileage because the tension on gas made it easier and more detailed from going to 10% throttle to 20% back to close then going 10% to 50% then close. I paid nomore than 3 bucks for it and it is well worth it. Quote Link to comment Share on other sites More sharing options...
Challenger Posted October 31, 2010 Share Posted October 31, 2010 (edited) I wonder if the spring will be strong enough to make a difference. Since NO one here knows if its infact your fault I wont comment on it. Im sure your not so incapable of motor skills (controlling your foot) to where you cant slowly move your foot. That being said, you have a few options as mentioned in the first response you can modify the linkage. When the arm and link are closer to 90 degrees youll have less displacement of the rod for a given rotation of the arm. The article explains it better. Other option is to use a cable linkage with a 240sx throttle body. Edited October 31, 2010 by Challenger Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 31, 2010 Share Posted October 31, 2010 "Stiffen up the springs" simple? "Throttle Body Return Spring"---is that replacing the stock T/B spring because it was worn out? Or is this an additional spring you 'simply' attach somewhere---where was that you attached it agian? And when it fails, falls off, or something breaks---what does that spring do then? Yeah, 'simple answer'... Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 31, 2010 Share Posted October 31, 2010 HAHA this post is funny...this guy only needs a simple answer. Probably frustratingly funny. Because it does seem so simple. It's just a board you push on with your foot, and one simple looking spring that brings everything back. When I got my car though, it had a spring from the top of the throttle linkage stretched across the top of the valve cover to return the throttle. The original was broken. The linkage was all gummed up so I had to put a strong one in the original position to get the throttle to stop hanging open. I found that the stronger springs were more difficult to control, because you have to put more effort in to moving the pedal off closed throttle position. I spent a lot of time lubricating all linkage rotation points so that I could get the lightest spring possible on. It took a while to get it right but made a big difference. Try a lighter spring and a can of WD-40. He probably already rear-ended someone in stop-and-go traffic and won't be back.... Quote Link to comment Share on other sites More sharing options...
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