Eviljohn
|
| posted on 1/8/17 at 06:58 PM |
|
|
Do i need tps?
Hi all. Hope you are well. I am part way through a bike carb conversion on a 1983, 1043cc polo. I'm using the carbs from a cbr400. They
didn't come with the tps sensor. I've been reading a little about them and wondered if anyone could say whether i actually need the tps or
not.
From what i've read, and feel free to correct me if i've misunderstood, before tps, or other similar, the two things engines used to
correct fuel/air mix were vacuum advance and centrifugal weights in the dizzy.
I actually have vacuum advance in use on my engine. Would that mean i don't have to use a tps system or i have i misunderstood it?
Thanks for stopping by and any guidance you can give.
|
|
|
|
|
rayward
|
| posted on 1/8/17 at 07:02 PM |
|
|
if your running carbs , you would only need TPS if your running a 3D mappable ignition system (such as megajolt)
hope this helps
Ray
|
|
|
cliftyhanger
|
| posted on 1/8/17 at 08:37 PM |
|
|
If you have a distributer, then fine.
If running something like megajolt/nodiz or whatever, not using a TPS or MAP sensor means you will lose torque and economy at cruise.
MAP sensors do the same thing as TPS (in fact are often better, long story!) in that they alter the timing according to manifold pressure. So
effectively work in the same way.
|
|
|
Eviljohn
|
| posted on 2/8/17 at 06:53 AM |
|
|
I have refurbished stock distributor. When i had it refurbed, had it converted from points and condensor to electronic ignition. But does still have
vacuum advance unit fitted.
Thanks for advice gents. Very much appreciated.
|
|
|
Jenko
|
| posted on 2/8/17 at 07:40 AM |
|
|
quote:
Originally posted by Eviljohn
I have refurbished stock distributor. When i had it refurbed, had it converted from points and condensor to electronic ignition. But does still have
vacuum advance unit fitted.
Thanks for advice gents. Very much appreciated.
All the TPS does is feed back throttle position information to an ECU. The ECU can then decide what ignition advance to give and what fuel to inject
(if it were on a fuel injected car). If you don't have an ECU controlling fuel or ignition, then there is no requirement for a TPS.
MY BLOG - http://westfieldv8.blogspot.co.uk/
|
|
|
redturner
|
| posted on 2/8/17 at 08:14 AM |
|
|
I run my Zetec with R1 carbs on Megajolt using the MAP sensor. I could have used the TPS but I found it more convenient to remove it and connect the
throttle cable to that end.....
|
|
|
mcerd1
|
| posted on 2/8/17 at 08:36 AM |
|
|
quote:
Originally posted by Eviljohn
I have refurbished stock distributor. When i had it refurbed, had it converted from points and condensor to electronic ignition. But does still have
vacuum advance unit fitted.
^^ as above you don't need the TPS - its only for ECU controlled sparks (in place of the vac. advance or MAP sensor)
but to get a good vac. signal for the dizzy you will need to connect up a vac. line from all the cylinders into a chamber bid enough to smooth out the
individual pulses from the cylinders - then take a line from this chamber to the dizzy - without this the pulses from 1 cylinder will potentially
bounce the spark timing all over the place 
the other approach is to modify the dizzy to remove the vac. advance completely (suitably locked at a fixed advance) - this effectively make it a 2D
ignition map which is simple, but will give poor economy and less throttle responce
[Edited on 2/8/2017 by mcerd1]
-
|
|
|
SPYDER
|
| posted on 2/8/17 at 10:37 AM |
|
|
quote:
Originally posted by mcerd1
... you will need to connect up a vac. line from all the cylinders into a chamber bid enough to smooth out the individual pulses from the cylinders -
then take a line from this chamber to the dizzy ...
A lot of people use one of these. Myself included. Mine's a large one.
|
|
|
redturner
|
| posted on 2/8/17 at 01:02 PM |
|
|
I fancied that idea but thought that 4 separate pipes into a small manifold then 1 at other end to go to the ECU would be better...
|
|
|
Eviljohn
|
| posted on 2/8/17 at 05:12 PM |
|
|
I kept the vaccum hooked up to the new manifold. Drilled a hole and attached a little take-off. Hooked it up as it was when the stock manifold was in
place.
Not sure how that affects the running at the moment as it's running poop anyway. Have to move the fuel pump and see how that works so will
probly be back for more guidance after that!
Thanks for guidance so far. Very much appreciated.
|
|
|
mcerd1
|
| posted on 3/8/17 at 11:33 AM |
|
|
^^^ sounds like you'll need to connect up all the cylinders 
like this: (MAP sensors need connected the same way as your mechanical advance )
[Edited on 3/8/2017 by mcerd1]
-
|
|
|
Eviljohn
|
| posted on 3/8/17 at 05:27 PM |
|
|
Just to make sure i understand it:
I attach a vacuum hose to each inlet pipe/runner and hook all 4 of those up to the vacuum advance, with a fuel filter after the last runner?
[Edited on 3/8/17 by Eviljohn]
|
|
|
David Jenkins
|
| posted on 3/8/17 at 05:33 PM |
|
|
quote:
Originally posted by Eviljohn
Just to make sure i understand it:
I attach a vacuum hose to each inlet pipe/runner and hook all 4 of those up to the vacuum advance, with a fuel filter after the last runner?
Or 4 pieces of hose, 1 from each inlet, into a small cylinder (like the fuel filter) then on to the distributor. Whatever's most convenient.
|
|
|
