4age Running Out Of Revs

[AlexK]

Hi guys,

 

Looking for your expert advice/help.

 

I have recently installed a Blue top into my honda s600 for hillclimb work.

The engine itself is producing 68kw ATW with peak power at 6250RPM. I am happy with the power ( std ECU) but with my gearing a few more revs would help out ( mid corners).

 

The engine runs out of Revs at 6700RPM (seems a little low).

 

I am not running any O2 sensor - Would this cause the problem?

 

I have a surge tank and am running 2* EFI pumps (external). As mentioned it is std ECU. I am running 5/16 fuel line to engine and 1/4 back to the fuel tank. Home made extractors ( limited space) are 4-1.

 

Your help is much appreciated.

[love ke70]

have you got the speed sensor connected?

if the ecu is getting no road speed signal it will think you are free-revving the motor and lower the limiter.

[AlexK]

Engine was out of AE82 - I don't have the speed sensor connected but thought ( through Phil Bradshaw's page and others) that this was not required to be connected.

 

I stand to be corrected though.

 

If needed what can I do to have it disconnected ( ie do I need to set a voltage to it of a value)?

 

thanks

[Raven]

You may need to get a little magic box called a Speed Cut Defender, or, if you wanted more tunability out of the 4AGE, i'd go for something like a Microtech or Wolf 3D ECU instead.

[love ke70]

raven, what does a speed cut defender do? i always thought it stopped the ecu rev limiting you at 180 or whatever, but I'm happy to be wrong as i have never looked into such a device.

alex, i would look at hooking a speed sensor up, i have no first hand experience, but it was a relaible source that i heard that mentioned from.

if anyone knows any better, feel free to disprove me.

[Trev]

A speed defender changes the amount/variations of pulses the speedo sends to the ecu so u can go faster, I have read that you can use a reed switch to make a speed sender, I will have a dig and see what i can find.

Edited May 7, 2007 by Raven

[Raven]

raven, what does a speed cut defender do? i always thought it stopped the ecu rev limiting you at 180 or whatever, but I'm happy to be wrong as i have never looked into such a device.

 

As far as I'm aware it does what Trev said it does. Allows you to go faster but you still have the speed sensor hooked up, it just doesnt limit the car to 180km/h, therefore allowing the car to rev properly and also exceed 180km/h (on private roads of course) and by going by what was said about the rev limit being lowered because it thinks the car is free-revving while driving, it should allow the car to function properly and rev properly.

 

Be interesting to see what Trev comes up with regarding the Reed Switch set-up though as I think that will save people a lot of money providing its a simple and cost-effective way of bypassing the speed sensor all together.

[Des]

I need mine hooked up in my car as it turns itself off under hard braking and the check engine light is f@$king bright but its a different car.

[love ke70]

http://www.rollaclub.com/board/index.php?s...ic=9392&hl=

[Trev]

http://www.rollaclub.com/board/index.php?s...ic=9392&hl=

 

Good link, I don't think i will have to find the 1 I seen

[Des]

I need mine hooked up in my car as it turns itself off under hard braking and the check engine light is f@$king bright but its a different car.

Found my fix and it actually works. :S

[AlexK]

thanks guys for all the helpful advice.

 

I will look into the flasher relay and let you know how I go.

[AlexK]

Hi Guys,

just reading the article more closely on the flasher unit. Is this saying that the SPD point of the ECU gets shorted to gnd(earth) every 3-4 seconds by way of a relay and flasher?

 

or is it saying that the actual signal ( from the speedo I presume) that guys who have the speed limiter connected, get's shorted to gnd.

 

I only ask as I do not know what the SPD signal should look like as I do not have the original speedo/ set-up.

 

Before I go shorting the SPD point to gnd (3 times a second) it would wise of me to ask the impact.

 

Is the signal to the SPD of the ECU a square wave? If so what is hte peak voltage ( 5V or 12V)?

 

 

thanks again.

[AlexK]

Hi Guys,

 

searched on toymods and found the answer to my own problem relating to 20V. It appears you can connect the #10 (idnitor pulse) to SPD to trick the ECU into thinkinga SPD is connected. Also in the link below it confirms that the pusle is a negative pusle ( to gnd).

 

I'll now go forth with some confidence with the flasher can and relay method and advsie of my success or otherwise.

 

thanks again.

 

 

http://www.toymods.net/forums/showthread.p...t=speed+limiter

[AlexK]

;)

Hi guys,

 

for those interested the flasher unit supplying a signal to the SPD on the ECU works a treat. I now have up to around 7500RPM (rev limit) as compared with the 6700 RPM experienced with no signal at the SPD point. Thanks guys for your help. The car now runs great on hillclimbs...

 

I have a mate making the 555 timer cct which will reduce the size and remove the flasher can noise.

 

For those undertaking the flasher can method be aware that flasher cans require a load connected to them of 2 globes(1 globe flashes a bit fast). 2 globes can get quite hot so need to be insulated. At the moment I inserted into a broken rear tailight and shoved in my glovebox.

 

regards

 

Alex.