NITROUS OXIDE ( nos / n2o ) advice forum

Hi

When testing my Minimax and TPS with no nitrous connected, engine stopped. I have noted that the pulsoids activate immediately the throttle pedal hits the point at which the TPS is set too, as expected.

When doing the road tests however, I have noticed there is a slight delay of between 0.5-0.75 sec before the pulsoids activate after the throttle hits the floor.

Is this normal?

Thanks in anticipation.

If you have the controller armed with the nitrous turned off you will flood the engine with petrol !

If you can feel a delay in activation when testing on the road I would think it could be down to not having the controller set up right or low bottle pressure or a long length of nitrous pipe to the Pulsoid.

Hi and thanks for your reply.

For the road test, the nitrous is turned on

The delay I'm talking about is the activation of the Minimax, not a delay in the onset of extra boost.

What I mean is, on the road with everything connected up, when I put my foot down to the floor, the pulsoids don't activate and display on the Minimax doesn't change to "--" straightaway. There is a delay before anything happens.

The delay isn't present during testing of the system alone (pipes disconnected, engine not running, ignition on, Minimax on) under these circumstances, the Pulsoids activate and Minimax indicates "--" as soon as the throttle pedal reaches the position at which it is set for (80-90% WOT).

On the road with everything connected up, there's a delay. Once or twice the pulsoids didn't activate at WOT. I was wondering if the ignition is affecting or interfering with the TPS?

I should add:

I have wired the WON TPS to the car's TPS on the throttle body.

I was wondering if it should be wired into the throttle pedal instead (the instructions don't specify which).

I was wondering if the car's "fly by wire" software initiates a slight delay between the foot pedal and actual throttle position? Essentially, not allowing me to whack open the throttle when the engine is running by opening the butterfly more slowly towards WOT.

You have me on that one Mark !

I only ever use a micro switch to detect Wide Open Throttle on any car I fit nitrous to. We recently fitted a system to a V6 Rover 75 and we fitted a micro switch on the TB cam so the controller gets a clean on / off signal as soon as the throttle is at around 90% open

This by passes any other electrical influence on the controller. I do this because I'm old and I like simple analogue signals from mechanical devices. All of my race cars use carbs and distributors and I like to keep thing simple. Having said that, my younger race buddies are all about computers, ECU's and laptops

I'm sure Trev will be able to chip in now to explain the TPS stuff !

Regards
Perry

Hi Perry

I'm no expert on these "modern" systems either.

If there are any Volkswagon/Audi techs out there: Can the ECU override my throttle input?

Eg. Under normal "no nitrous" conditions: If I "request" WOT by putting my foot to the floor, the car's computer will oblige by opening the throttle. BUT say there's not enough fuel flow (low pressure or blocked jets) will the ECU attempt to prevent the AFR from going too lean by retarding the throttle response, allowing the fuel flow time to "catch up"?

In which case, it could be a sign I need to check over my fuel system. The car has over 120k miles on the clock.

NB. In the past, before fitting the nitrous kit, I had noticed that, when accelerating hard, the rate of acceleration would increase more rapidly if I backed off the throttle very slightly until I reached about 5000rpm then I could I could put my foot to the floor.

I have considered that the Audi TPS my be at fault but when the engine is not running, the throttle response is linear, exactly 1:1 and instantaneous.

Best regards, Mark.

No is exactly what it is Mark, as NO throttle blade is programmed to respond instantly to full open when the peddle is mashed to the floor.
You should be able to connect our TPS unit to the peddle sensor to overcome that delay if you're unhappy with it.

Thanks Trevor.

I have since found that you can get a "Throttle Booster" that overrides the OEM programming whenever you need it, at the flick of a switch, essentially giving the driver instant throttle response for "improved performance". Might be worth looking into but it's rather expensive (around £140) for what it is.

I solved the issue in a simpler way. I just changed the point at which the TPS activates. Originally I had it set to operate at about 90-95% throttle, so I moved it to more like 80-85%. Now there's no noticeable delay.

Cheers.

Bugger I should have suggested that myself, so well done for figuring out that option.