Speed Limiter Controller
04-14-2005, 09:08 PM
#41
Senior Member
SL Member
Join Date: Mar 2005
Location: Morgan, Utah
Posts: 1,182
I have been to Jackson Racing, did not know they had a driving school, the shop is in the LA area, forget which burb, they do auto repairs and SC systems, nothing there said anything about a school, maybe they added it later.
True, slamming gears is not the proper way to shift, when you are road racing, autocrossing, daily driving, etc. I was refering to drag racing which beats the heck out of your whole drivetrain. Then it is better to shift as quickly as possible and that can be considered slamming to most if they have not mastered very fast shifting. Not lifting is better on the upshifts, the gears are spinning at a better rate than if you lift the throttle and the engine does not go up and down a massive rev range while doing so. Best to have a clutch stop as well so you only depress it just far enough. I learned this from a drag car builder with 27 years of experience both in domestic and imports, I think he may have a good idea of what is best;)
Of course a taller TIRE will change your final drive ratio but at the expense of having the worst possible place to have weight on a car moved even further out from the center of where it spins and possibly more weight as well, not a good idea from a pure performance standpoint. Weight is the enemy of all true performance, unsprung weight is the worst culprit, when you move that out to the furthest location you can, you are really taking a performance hit. Why I cannot stand the big wheel "performance" look, it is silly at best. Show cars, ok, I get it to a point, street or race cars, hardly (a few classes of certain types of race cars do benifit but that is mainly a factor of needing massive brakes. Also, larger diameter tires will still upset you Odometer and speedometer readings which needs to be addressed if you went tall enough to make a usefull gearing difference.
When I autocross and road coarse a car, or do some fun canyon runs, I lift when I upshift, do my best to rev match when downshifting, etc. On a tight course I may just pop in the clutch instead of upshifing or bouncing off the rev limiter because I am at a shift point right before a corner, I just jump on the brakes, lift the throttle, slid the clutch in just enough to disengage it then as my speed comes down I rev match and release the clutch. Far faster that shifting twice in such tight confines and less chance of missing a gear and ruining a good run.
But, I sometimes do not lift on the autocross course, if I have a nice straight and can bang a gear and gain a fraction of a second or so, I go for it.
Then again, I am more than willing to take full responsibility for my actions and fix what I break, seldom break anything though, main reason I drive Toyota products
OK, I really do not intend to come accross as a know it all because I certainly do not. I do know quite a bit and have alot of real world experience as well as have known many with vast knowledge and a history of success. When I do not know the answer I go to them to get it, not repeating something somebody said online or in a misguided magazine article. (There are alot of great writers in the inport industry that do know their stuff, I learn from them as well
I get a little impatient with some of the well meaning but misguided advice I have seen on this forum, normally I am very mellow and helpfull, I will go back to who I really am and be nicer
Rick
True, slamming gears is not the proper way to shift, when you are road racing, autocrossing, daily driving, etc. I was refering to drag racing which beats the heck out of your whole drivetrain. Then it is better to shift as quickly as possible and that can be considered slamming to most if they have not mastered very fast shifting. Not lifting is better on the upshifts, the gears are spinning at a better rate than if you lift the throttle and the engine does not go up and down a massive rev range while doing so. Best to have a clutch stop as well so you only depress it just far enough. I learned this from a drag car builder with 27 years of experience both in domestic and imports, I think he may have a good idea of what is best;)
Of course a taller TIRE will change your final drive ratio but at the expense of having the worst possible place to have weight on a car moved even further out from the center of where it spins and possibly more weight as well, not a good idea from a pure performance standpoint. Weight is the enemy of all true performance, unsprung weight is the worst culprit, when you move that out to the furthest location you can, you are really taking a performance hit. Why I cannot stand the big wheel "performance" look, it is silly at best. Show cars, ok, I get it to a point, street or race cars, hardly (a few classes of certain types of race cars do benifit but that is mainly a factor of needing massive brakes. Also, larger diameter tires will still upset you Odometer and speedometer readings which needs to be addressed if you went tall enough to make a usefull gearing difference.
When I autocross and road coarse a car, or do some fun canyon runs, I lift when I upshift, do my best to rev match when downshifting, etc. On a tight course I may just pop in the clutch instead of upshifing or bouncing off the rev limiter because I am at a shift point right before a corner, I just jump on the brakes, lift the throttle, slid the clutch in just enough to disengage it then as my speed comes down I rev match and release the clutch. Far faster that shifting twice in such tight confines and less chance of missing a gear and ruining a good run.
But, I sometimes do not lift on the autocross course, if I have a nice straight and can bang a gear and gain a fraction of a second or so, I go for it.
Then again, I am more than willing to take full responsibility for my actions and fix what I break, seldom break anything though, main reason I drive Toyota products
OK, I really do not intend to come accross as a know it all because I certainly do not. I do know quite a bit and have alot of real world experience as well as have known many with vast knowledge and a history of success. When I do not know the answer I go to them to get it, not repeating something somebody said online or in a misguided magazine article. (There are alot of great writers in the inport industry that do know their stuff, I learn from them as well
I get a little impatient with some of the well meaning but misguided advice I have seen on this forum, normally I am very mellow and helpfull, I will go back to who I really am and be nicer
Rick
04-14-2005, 11:14 PM
#42
Senior Member
Team Sushi
SL Member
Team N.V.S.
Scion Evolution
Join Date: Jun 2004
Location: Bangkok, Thailand
Posts: 4,322
ah! Drag racing, then that changes the game! Yeah. . . they don't really care about clutches in the world of professional drag racing. . . did you know that a top fuel clutch only lasts 1 run? They're lucky to get two runs out of em. In fact, it gets so hot in there, that the clutch fuses together with the drivetrain. Haha!
But yeah. . . a street clutch may take it a few times, but in the long run, it may seriously wear out a clutch prematurely.
But yeah. . . a street clutch may take it a few times, but in the long run, it may seriously wear out a clutch prematurely.
04-14-2005, 11:20 PM
#43
Senior Member
Team Sushi
SL Member
Team N.V.S.
Scion Evolution
Join Date: Jun 2004
Location: Bangkok, Thailand
Posts: 4,322
oh and oops, my bad. . . I'm mixing up my people. . . my brother's was workin with Skip Barber, at Laguna Seca. . . I don't know why I said jackson racing. I was probably reading a magazine.
04-15-2005, 12:09 AM
#44
Senior Member
SL Member
Join Date: Mar 2005
Location: Morgan, Utah
Posts: 1,182
Now we are getting on the same page
Skip Barber I have known about for a very long time.
I am not that much into drag racing, it is fun but I prefer the total overall dynamics of performance, handling, braking, etc. I love it all though and do plan to drag the car some but not alot, just to hard on gear for the short duration of the fun;) It is a nice benchmark of performance and cool to be fast of course!
Those top fuel guys are pretty crazy, same as the guys in little boats with the same engines, even crazier in some ways. I know they tear down everything after every run, Darton makes most of sleaves for the blocks, often they use a new set for every pass! Darton made a custom set for my Matrix Unfortunately I was not able to use them, sold out everything to help my disabled buddy, took a break for a couple of years, now getting back into the game but the tC does not need the sleaves, can run stock rods and pistons quite reliably for along time, sweeeetttttt!!!
Rick
Skip Barber I have known about for a very long time.
I am not that much into drag racing, it is fun but I prefer the total overall dynamics of performance, handling, braking, etc. I love it all though and do plan to drag the car some but not alot, just to hard on gear for the short duration of the fun;) It is a nice benchmark of performance and cool to be fast of course!
Those top fuel guys are pretty crazy, same as the guys in little boats with the same engines, even crazier in some ways. I know they tear down everything after every run, Darton makes most of sleaves for the blocks, often they use a new set for every pass! Darton made a custom set for my Matrix
Unfortunately I was not able to use them, sold out everything to help my disabled buddy, took a break for a couple of years, now getting back into the game but the tC does not need the sleaves, can run stock rods and pistons quite reliably for along time, sweeeetttttt!!!Rick
04-15-2005, 01:54 AM
#45
Senior Member
SL Member
Join Date: Dec 2004
Location: Buffalo, NY
Posts: 256
Originally Posted by tc05
what is the redline on the Tc, i hear its around 5900 just want to know, if its around there do you think we are at a disadvantage when it comes to ther vehicles like teh mazda3 or teh celica with a higher redline
01-09-2007, 07:23 PM
#48
Member
Join Date: Dec 2006
Posts: 36
01-09-2007, 07:41 PM
#49
Senior Member
SL Member
Join Date: Aug 2006
Location: Pittsburgh, PA
Posts: 1,520
Originally Posted by Otocan
there isn't a TRAC fuse for the speed limiter like there are on older cars like the JZ supra engine. it's programmed into the ECU, the only way around it is a piggyback or reprogrammed ECU, I'm not sure if that will work or not but Scionspeed is working on it and they are very close to a solution.
oh, and the theoretical top speed of gearing on a manual is 139.4mph with stock tires. auto is 163.7mph @ 6247rpms but you would need OVER 340whp to overcome drag to get up to those speeds.... the Scionspeed stage 3 turbo ought to be able to do that... here's a pic I stole from another forum, property of Zoltiz
oh, and the theoretical top speed of gearing on a manual is 139.4mph with stock tires. auto is 163.7mph @ 6247rpms but you would need OVER 340whp to overcome drag to get up to those speeds.... the Scionspeed stage 3 turbo ought to be able to do that... here's a pic I stole from another forum, property of Zoltiz
Well it says first gear goes to 30, and 2nd goes to 52. My first gear only goes to 24-25 when the gas shuts off, but 2nd gear makes it all the way to 60 when the gas shuts off. The other 3 gears look correct though, anyone else notice this.
01-10-2007, 02:31 PM
#52
Senior Member
SL Member
Join Date: Nov 2005
Location: Asia, NY
Posts: 153
Hi there all,
Read about the interest in delimiting the speedo...
There are 2 sensors that read speed from your transmission housing. You can see them both below your intake box (I'm assuming this on the auto tC).They're black in color and in the ECU pinout diagram you see it as NC(T)+ and NC(T)- (you need to check the ECM manual). These 2 buddys are the speed pulse signal sensors. Do not confuse them with NE+ and NE-, they are the sensors for crankshaft rotation.
Next, the speed signals generated at the tranny housing are sent to the speedometer housing aka dashboard in 4 pulse per m/s (you need to check the oscilloscope profile in the tC service manual). Dismantle the speedometer housing and check the back, you should see 2 pin ports, A has 24 pins and B has 16 pins (check the service manual or physically, this might be different for the tC since my car is JDM).
A represents INCOMING signals from various engine sensors (includes speed signal) and B represents OUTGOING signals to the ECM (Engine Control Management) unit. (you need to check the tC ECM manual/Toyota tech notes to confirm this)
The processed (outgoing) signal is in turn sent to the ECM. From what I know, if you spliced a product at the ECM point, it ain't gonna work to delimit the speed. As someone mentioned earlier, there are 2 control units that govern speed limit in the car. The speedo housing and ECM are the 2.
The speed signal needs to be clamped or modified AT THE DASHBOARD BACK housing NOT at the ECM unit. The raw signal CANNOT be sent to the ECM through the dashboard housing unit. Period.
I managed to get a special delimiting unit from a UK company (they do pure auto electronics) which requires you to spliced their box wire to the INCOMING signal at dashboard back and cut off the OUTGOING wire to ECM. Tape up the cut portion and join/solder their box wire to the OUTGOING signal wire that is dangling from the remaining harness which leads to the ECM unit.
I believe the unit replicates the pulse signal and as speed builds up, the 4 pulse gets higher and higher (compressed). The ECM cuts fuel at a factory preset frequency based on the 4 pulse (20/ms). To get around, the replicated signal through the box generates a similar signal but at a different rate which fools the ECM into thinking the speed limit has not been breached since it is being fed the processed signal from the box. I think this is how it works, not too sure.
Our cars are limited to 112mph in Asia. Based on the same gear ratios and sun gear/final drive of 2.740:1, you can reach 163mph. This assumes you are rolling on stock dimension wheels and tires. If you increase wheel/tire size, you have a higher top speed. When 2008 arrives, it is mandatory to be CAN enabled, all ECM/ECT/sensors will be cross-linked and this would be another hurdle for performance tuning. Currently the RX8 and 350Z are CAN BUS protocol based and to get around the speed cut, only HKS has the delimiting device but it costs 7 benjis ($700). Damn, expensive
As usual, no one has been successful in cracking the Toyota program codes, unlike Hondata for Honda/Acura 
I'm rolling on 275/40-20 on my ride, based on calculation from the gear ratios and final drive, this translates into a top speed of 184mph @ 6250rpm when speed is delimited. Of course you would need the power to push the car to reach this speed and a long stretch of road space as well
I hope this would help you guys to look into the right direction and that raamaudio and Dezod can look into this area for US Toyota/Scion owners. With the kind of power you guys are pushing, you ought to beat/own most hi-performance cars on a nice highway race
Looking forward to more conquests from tC owners
Read about the interest in delimiting the speedo...
There are 2 sensors that read speed from your transmission housing. You can see them both below your intake box (I'm assuming this on the auto tC).They're black in color and in the ECU pinout diagram you see it as NC(T)+ and NC(T)- (you need to check the ECM manual). These 2 buddys are the speed pulse signal sensors. Do not confuse them with NE+ and NE-, they are the sensors for crankshaft rotation.
Next, the speed signals generated at the tranny housing are sent to the speedometer housing aka dashboard in 4 pulse per m/s (you need to check the oscilloscope profile in the tC service manual). Dismantle the speedometer housing and check the back, you should see 2 pin ports, A has 24 pins and B has 16 pins (check the service manual or physically, this might be different for the tC since my car is JDM).
A represents INCOMING signals from various engine sensors (includes speed signal) and B represents OUTGOING signals to the ECM (Engine Control Management) unit. (you need to check the tC ECM manual/Toyota tech notes to confirm this)
The processed (outgoing) signal is in turn sent to the ECM. From what I know, if you spliced a product at the ECM point, it ain't gonna work to delimit the speed. As someone mentioned earlier, there are 2 control units that govern speed limit in the car. The speedo housing and ECM are the 2.
The speed signal needs to be clamped or modified AT THE DASHBOARD BACK housing NOT at the ECM unit. The raw signal CANNOT be sent to the ECM through the dashboard housing unit. Period.
I managed to get a special delimiting unit from a UK company (they do pure auto electronics) which requires you to spliced their box wire to the INCOMING signal at dashboard back and cut off the OUTGOING wire to ECM. Tape up the cut portion and join/solder their box wire to the OUTGOING signal wire that is dangling from the remaining harness which leads to the ECM unit.
I believe the unit replicates the pulse signal and as speed builds up, the 4 pulse gets higher and higher (compressed). The ECM cuts fuel at a factory preset frequency based on the 4 pulse (20/ms). To get around, the replicated signal through the box generates a similar signal but at a different rate which fools the ECM into thinking the speed limit has not been breached since it is being fed the processed signal from the box. I think this is how it works, not too sure.
Our cars are limited to 112mph in Asia. Based on the same gear ratios and sun gear/final drive of 2.740:1, you can reach 163mph. This assumes you are rolling on stock dimension wheels and tires. If you increase wheel/tire size, you have a higher top speed. When 2008 arrives, it is mandatory to be CAN enabled, all ECM/ECT/sensors will be cross-linked and this would be another hurdle for performance tuning. Currently the RX8 and 350Z are CAN BUS protocol based and to get around the speed cut, only HKS has the delimiting device but it costs 7 benjis ($700). Damn, expensive
As usual, no one has been successful in cracking the Toyota program codes, unlike Hondata for Honda/Acura I'm rolling on 275/40-20 on my ride, based on calculation from the gear ratios and final drive, this translates into a top speed of 184mph @ 6250rpm when speed is delimited. Of course you would need the power to push the car to reach this speed and a long stretch of road space as well
I hope this would help you guys to look into the right direction and that raamaudio and Dezod can look into this area for US Toyota/Scion owners. With the kind of power you guys are pushing, you ought to beat/own most hi-performance cars on a nice highway race
Looking forward to more conquests from tC owners
Thread
Thread Starter
Forum
Replies
Last Post
daniinpitt
Scion xB 2nd-Gen Owners Lounge
1
04-04-2015 08:07 PM
