Is it safe to remove haldax fuse for running on dyno

s3evil34

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Just been researching but can't find much info on this. I only ask as just had my s3 mapped at celtic tunning and they said the haldax was pulling the car back on the dyno! And as a result my dyno graph is all over the place! No smooth power curve and not accurate on bhp and torque. They did not want to pull the fuse as thought it could damage the haldax controller. But I hear a lot of tuning firms map 8l s3, s in front wheel drive. Anyone had any experience in this?
 
On short runs pulling the fuse is fine... Do it all the time

<tuffty/>
 
I was driving with removed fust on haldex for 2 months and no problems at all. Now fuse on and everything is working pefectly.
 
I'm thinking of calling up celtic and seeing if they will stick it on the dyno again in front wheel drive and see what my figures really are. Am I right in saying it's fuse 31 in the box to remove for haldex? Fuse box in engine or in the cabin?
 
It's normal practice to remove the fuse on a Haldex if the tuning place only has one set of rollers. As long as there is no issue with the Haldex it should disengage and there will be no power transmission to the rear wheels.
This was how my car was mapped at Unicorn even though Rick has a linked 4WD dyno that will do 4WD cars.
274bhp 295Ft/lbs torque. Badger V2.2 TIP, 3 inch DP and decat pipe. 4 bar FPR, Ramair filter. Wellycooler intercooler.


BEFORE AND AFTER REMAP001
 
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This is what I thought. I think celtic where just covering them self buy not removing it. They had 2 dynos both four wheel drive. They did mention something about they did not want my car to power the dyno buy its own power? Not sure what they ment buy that? Unless when a 2 wheel drive car goes on the rear rollers still turn the rear wheels? Who no, s. Thanks for the advice guys
 
Added a video and some other stuff to my previous post. You can see Ricks dyno is a 4WD dyno but only the front wheels are being used. Fuse was removed for the Haldex.
 
I was driving with removed fust on haldex for 2 months and no problems at all. Now fuse on and everything is working pefectly.
Thats less of a problem as the rears are still turning while driving...

The issue is when the rears are not turning and the fronts are... this means that only one half of the haldex plates are turning and can generate too much heat damaging the clutch plates... on short dyno runs this is ok as the heat is manageable but sustained use can cause wear of the plates...

<tuffty/>
 
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...just make sure the haldex oil is changed regularly and if you don't know the last time it was changed do it after you have had the run on the dyno...

<tuffty/>
 
The Haldex is not on 100% of the time and only about 5% output anyway - S3s are commonly not referred to as "real" 4WD whatever one of those is.
 
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Good advise guys hopefully then they can spin the rear wheels with the dyno. As I feel a bit cheated that I don't have a print out that shows me true values. So that is the main concern then clutch plates getting to hot. I hopefully only need one dyno run for a power print out.
 
Also desert storm fantastic results with the tt. Was much work needed to get that power? Not including mods. Ie boost leaks coil packs sticking actuator etc.
 
I presume car had been back to Audi and had the coilpacks replaced as they were the latest revision. Car had a small boost leak in the PCV system which is normal for these. It was a completely standard 88K mile car when I got it. Haven't touched the turbo or N75 all that seems OK. All the mods add together to get a good result. I have a DW65V fuel pump to put on the car as I think the fuel pump is not making as much pressure as it should at the top end. The standard injectors are pretty much maxed out even with a 4 bar FPR.
 
I not checked the N75 and to be fair I never got round to doing a boost leak test before the map. I replaced all four coils and fitted iridium plugs changed all my fluids and it came out at 246. But as said with the dyno results are not correct.
 
Why did you replace all 4 coil packs and what did you use to replace them. the later OE ones are fine, some of the Ebay replacements are actually not that good.
 
Just been researching but can't find much info on this. I only ask as just had my s3 mapped at celtic tunning and they said the haldax was pulling the car back on the dyno! And as a result my dyno graph is all over the place! No smooth power curve and not accurate on bhp and torque. They did not want to pull the fuse as thought it could damage the haldax controller. But I hear a lot of tuning firms map 8l s3, s in front wheel drive. Anyone had any experience in this?
tell me they ran it on a 4wd dyno please if no fuse removed!
 
This is what I thought. I think celtic where just covering them self buy not removing it. They had 2 dynos both four wheel drive. They did mention something about they did not want my car to power the dyno buy its own power? Not sure what they ment buy that? Unless when a 2 wheel drive car goes on the rear rollers still turn the rear wheels? Who no, s. Thanks for the advice guys
i believe theirs is a dynocom thing..
belt drive measuring pair of rollers linked to the 6 rollers up front.. so ideal for a 4wd car even a haldex one, as its mechanically linked by the belt.. Independant front/rear rollers can often be very confused as haldex applies power to rear in an on/off manner as it see's fit..

Wondering why they did'nt just run it in 4wd, linked mode?
 
Why did you replace all 4 coil packs and what did you use to replace them. the later OE ones are fine, some of the Ebay replacements are actually not that good.
I replaced all four just to be safe. I did buy ebay ones with good feedback and 2 year warranty. I fitted the old ones today as I have a slight Misfire. You can feel it through the rev range only happend since the map.
 
i believe theirs is a dynocom thing..
belt drive measuring pair of rollers linked to the 6 rollers up front.. so ideal for a 4wd car even a haldex one, as its mechanically linked by the belt.. Independant front/rear rollers can often be very confused as haldex applies power to rear in an on/off manner as it see's fit..

Wondering why they did'nt just run it in 4wd, linked mode?
This puzzled me to! But I will call them on Tuesday. Do you think because the haldex was misbehaving on there dyno I have not got max power out of my map?
 
how could you possibly get max power with a misfire in any case? do you have the EML flashing during the misfire? I had a misfire and really struggled to identify the problem cylinder as no indication of cylinder - ended up disconnecting the N75 and pushing through when the misfire was happening instead of backing off until I got an EML - one of spark plugs was no good - although looked fine!
 
I ment more if the map has been put on will I not have as much power as I should even when the missfire is fixed? As it was mapped with a missfire. Or when fixed will it learn and use full potential of my map. So generally stage one map spark plugs should be gapped to 0.7 as thats what I will check next. Is that right?
 
Again thanks for the advise guys I always find get so much more help on forums then a lot of garages. Cheers
 
Dude... You have an open circuit fault code... It's not a spark plug... It's wiring related or a faulty coil pack...

<tuffty/>

As tuffty said in your other thread I doubt it’s spark plug gap is your problem other wise all four cylinders instead of just cylinder 3 the wiring loom get a lot of gear and can go brittle so check all the wiring if your sure it’s not the coil pack
 
Little hijacking. Would someone send me link for coils wiring harness?
I want to replace my AMK harness.
 
Anyone had any experience in this?

Direct you might say

as in good few years back I took a car to celtic for mapping

informed/demonstrated haldex fuse pulling to effect to them

Let them have go at mapping; they admitted they didn't know how to actually build a custom map after about 3 weeks trying and lying
 
I ment more if the map has been put on will I not have as much power as I should even when the missfire is fixed? As it was mapped with a missfire. Or when fixed will it learn and use full potential of my map. So generally stage one map spark plugs should be gapped to 0.7 as thats what I will check next. Is that right?
mapped with a misfire? surely not..
eak!
 
mapped with a misfire? surely not..
eak!
Not mapped with a miss fire was running fine. But after the map it jerky at low revs and if you hold it at 4000 rpm in neutral the needle bounces a bit. As if you were hitting a rev limiter just not as aggressive.
 
can you go past 4k - I have launch control on mine and cant go over 4500rpm until I am moving faster than 5mph
 
Yeah u can rev it past! If u hold it at 2000 3000 etc it will do it. But it's more noticeable at 4000