has anybody got a system that cuts either/or fuel/ignition (i guess that cutting the ignition is safest for the engine?) so that you can change gear at full throttle?

and does it reduce lag? i.e. does the turbo keep spinning faster than it does with a dump valve?

 

does that system slow the engine down momentarily? wouldnt that make it a bit pointless as flat shifting is to keep the revs right up? but flat shifting isnt a good idea cos ure taking the load off the engine which will make it rev faster when its already flat out valve meets piston.....blah

 

if you're at (or near) the rev limit anyway, which is set by cutting the spark, how can the engine speed increase? maybe because of the sudden reduction in load when the clutch is pressed down? but surely not if you have stopped the ignition?

i was just thinking that if you keep the throttle fully open (of course there will be a decrease in revs as you engage the clutch if you've gone up a gear) the engine will still be working like an air pump at quite high speed so that it might keep the exhaust turbine spinning. on the other side, you no longer put a restriction in the way of the compressor airflow to slow it down. so i would think that the turbo would still be spinning relatively fast as you brought the ignition back in.

i don't know how much fuel would get injected during this time and if it would self ignite in the manifold and cause any damage, or flood the cylinder or cause lubrication issues?

 

Couldn't a quick shifter from a bike be adapted to perform this function. I guess it would have to cut the ignition for a bit longer than on a bike to allow for the longer time to change gear but the principal is the same isn't it ??

Martyn

 

any more information on these mr giles?

 

I had a full throttle shift on my Renault 5 GT Turbo. I think it was a combination of a rev limiter with a micro switch under the clutch pedal. No idea how it worked. Fitted by BB Performance Tuning.

All i know is that i could change gear without lifting off the throttle good at Santa Pod. Produced nice bangs and flames as well.

 

that sounds like the kinda thing i'm thinking about mate. did you get to time it up the pod with and without and see what difference it made?

i guess the bangs and flames were from the fuel that was injected when the ignition was cut - bet they piss on a flamer kit

 

All it is is a soft ign cut rev limiter activated by usualy a clutch switch, microdynamics, omex, etc sell em, bout 100-150quid

 

do they acheive anything though? is there effect much greater on a turbo engine than a n/a? hs anyone any experience/comments?

 

how effective is this? Does it actually make you go any faster?

 

does almost exactly what ALS does really, keeps the air and fuel flowing, most serious drag racers use it, so must be some effect, exactly how much i dont know but launch control is almost exactly the same tho while stood still, and thats been proven to give 1bar boost at 5000rpm while at a standstill (ie no load on engine, clutch down or neautral) on a low comp RS500 spec engine...

 

sounds good then, and cheaper than ALS.

can it damage anything from the unburnt fuel though? and will the revs fly up when the clutch is pressed(wouldn't want to try i first for obvious reasons)?

 

Yep, the Racelogic traction control system on my Cossie has a full throttle shift facility, it's not as easy to use as it sounds though!!!

PS. Of course, it's not my Cossie any more!

 

yes i have a system on mine that does full throttle shifts , and launch control , but then i also have a dog box and als so really only the launch control gets used !!

 

NO!
Had all the facilities on my Race Logic system & they aint a lot of good to be honest. If it worked i would still be using it, but i diconnected the system & threw it away. May try the latest Autronics system soon to see if any progress has been made.
Rod

 

Well i was running 14.8qtrs all day using it and 15.6qtr without. It is an easier run as you can keep on the gas pedal all the way.

Was Ł90 fitted.

I was advised that prolonged us would damage the clutch.
Bloody good fun though esp through town!!!!

 

Think pat dorans old Rs200 had full throttle gear change