megajolt.. TPS or MAP?

kokkolanpoika · Post by **kokkolanpoika** » Sat Jan 17, 2009 8:08 pm

Hi..

I´m thinking to upgrade my std Lucas ignition system for megajolt waste spark kit (triggerwheels.co.uk).

Question is?
Witch one is better my aplication? TPS or MAP to measure engine load?
Engine details.
5.2Litre
Stage 4 heads (maybe in future wild cat heads)
45mm trumpets
now siamesed plenum 2x65mm throttle (maybe ITB?)
Kent H228 mechanical cam 280/290deg. (Maybe in future some silly race cam +300deg?)

I ask same question from seller, he say that maybe TPS is better with my aplications?

What do you think folks?

I wonder if i take MAP kit and take the vacuum same place as original dizzy (before throttle disk)? So cam dosent actuate as much as after throttledisk?
+ I also wonder is there any vacuum before disk, because my airfilter/air
horn is so large (straight big horn to filter to throttle), that aint resist air flow anymore?

Or if i take a TPS kit. How good it is to recognise engine load (excample long hill) if i dont press any gas pedal?
(i think vacuum will change, but TPS signal dosent change then, =timing dosent change?) But if use MAP, timing will change without pressing gas pedal on long hill?

Any ideas?

CastleMGBV8 · Post by **CastleMGBV8** » Sat Jan 17, 2009 8:30 pm

Timo,

How do you intend to manage the fuelling as it may be simpler to go full Megasquirt to control both.

You could talk to Phil at Extra EFI who can advise on the ignition side as well as fuelling if you haven't already,

Link.

http://www.extraefi.co.uk/index.htm

Kevin.

kokkolanpoika · Post by **kokkolanpoika** » Sat Jan 17, 2009 10:08 pm

I manage my fueling by Haltech..
My choice is new Haltech E6 or my old Haltech + megajolt ignition..
Don´t like MS ecu:s..

I dont trust so much to MS fueling.. As my engine is too expensive to broke up..

Post by **katanaman** » Sat Jan 17, 2009 11:37 pm

MAP take off must be at full inlet vacuum, it does a very different job from the vac advance on a dizzy.
How do you manage your Haltech, is that MAP or TPS? If its MAP and it runs ok then MAP will be fine.

kokkolanpoika · Post by **kokkolanpoika** » Sun Jan 18, 2009 9:14 am

katanaman wrote:MAP take off must be at full inlet vacuum, it does a very different job from the vac advance on a dizzy.
How do you manage your Haltech, is that MAP or TPS? If its MAP and it runs ok then MAP will be fine.

I use TPS with my old stage3 4,6engine engine because idle mixture is mutch easier to adjust (no hunting as MAP do).. And also partload is easier to adjust..
5,2litre is out of my car, And first start is near in this month?

I can try firts std dizzy and then upgrade the dizzy..
Cam is almoust identical both setup.. But 5,2litre has got mechanigal..

I think TPS would be better?

Post by **katanaman** » Sun Jan 18, 2009 12:14 pm

Yes I would agree, if you had problems with MAP on your injection then your probably going to have it with ignition.

Eliot · Post by **Eliot** » Sun Jan 18, 2009 6:09 pm

As much as I hate TPS for measuring engine load, I think you may need it because of the siamesed plenum.
Ask phil ringwood at extraefi, as he had a siamesed plenum on his 5L engine and may be able to offer relevant advise.