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Discussion Starter · #1 ·
What are people using Rolling roads for?

Last time I used one was for a car with no electronics and a twin 40 Weber carbs. The chap was able to re-jet the carbs and check timing and such but with all the electronics on the Saab, are the techs at these rolling roads able to remap the trionic ECU for example and if so presumable only on 1994 onwards?

Or are you guys just working on the ECU job being in the bag and getting value from injector work/intercooler and exhaust stuff?

Thanks

David.
 

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usually a rolling road session is to confirm the work done is having the desired effects..

It is not normally possible to program the trionic
"on the road" altho I know a couple of guys who can...

all you can do is a bit of swapping about to see what things work

however I have a rr session planned to dial in my cams as this is the only way to do it
 

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Hirsch programmed my 9-3 with it on the dyno. They have the equipment to monitor everything and make changes to the mapping right there in the car. It was pretty cool to watch.
 

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I needed a rolling road to set up the second set of injectors, which have a set of pots to adjust fueling at 1000 rpm intervals. The computer then interpolates the fueling between each 1000 rpm increment.

A good rolling road session will help highlight any problem areas as it also gives you boost and lamda readings.
 

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Discussion Starter · #5 ·
Ylee, how are your cams adjustable? I'm interested from the technical point of view. Do they have different offsets that can be interchanged to provide different cam timing? I've never met a cam (never needed to ) which is anything other than just one where you bolt on the sprocket and plop the chain on in the right place.

Eric, I would expect the specialist tuners to have the ability to programme Trionic, was just wondering about the "run of the mill" RR's.

Jezmond, why have a second set of injectors and not bigger (suitably programmed) single ones? (again, asking through ignorance). Is it because you then don't have to get the Trionic ECU remapped but can use a piggy back unit?

Thanks!

David.
 

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It's not the cams lobes that are adjustable on ylee's car, but the timing, via these vernier cam wheels:



Jez's car doesn't have Trionic.
 

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Jezmond, why have a second set of injectors and not bigger (suitably programmed) single ones?[/b]
Because a single larger injector does not give a good spray pattern of accurate petrol flow at what would be the very bottom of it's possible opening times.

i.e if you have 2 small injectors that can flow accuratly from say 5 - 50 units of fuel in single units you can flow 5 - 100 units in single steps.

if you have 1 larger injector that flowed 10 - 100 units in 2 unit increments you loose the ability to flow under 10 units (probably needed to idle, pass emissions, run at 30mph with little throttle etc), and you can only flow 10,12,14 units of fuel loosing your fuel flow accuracy etc.

Andrew
 

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Discussion Starter · #9 ·
Thanks Bubbles, that's what I didn't get, I didn't know you could get those sprockets and couldn't understand any other way of timing the cam without some mechanism. It's all clear now.

Likewise Scaero, that makes sense so do you have a piggyback ECU for the second set of injectors then?

David.
 
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