been to the rolling road need afr advice

[gkjnr 0]

went to the rolling road this morning and got a power run done the graphs are below, anyway the guy says the car was making good power but was running lean at the low end and at the top ,it was marginal but says it could be fixed for £500 plus vat ! now i,m not sure if this is just a scare tacktic to get more cash from me so does anybody know how i can get the fuelling up and do the graphs look like its running lean ? i,m not sure so any help gratefully recieved

[kadvr6 0]

what injectors/fuel regulator/fuel pump you using??

[gkjnr 0]

its standard injectors , 4 bar reg and i think its a vr pump but i,d have to check that because i didnt do the conversion

[jaysVR6 2]

What charger are you using and do you know how much boost it's producing?

With those sorts of figures it looks like a Z charger to me if it's producing around 250hp, no?

I reckon that sort of dip your seeing at the top of the graph will be a mapping issue imo. To be fair I've seen much worse graphs than that. My old charged VR was running a Z Engineering charger and because you're running standard injectors they are running near on 100% at full throttle to give the engine the fuel it needs.

If I'm correct in thinking you're running a Z engineering charger with 6psi, if you swap the injectors to a different set, they will need to be run very low as they are like buckets compared to standard ones and the car will tend to over fuel.

There is no real happy medium with a Z unless its a stage 2 which runs a little more boost and comes with larger injectors.

Be interesting to see if i'm correct with the charger guess

[gkjnr 0]

yep zr2 charger, what i really want to know is do i spend another £550 to sort it or is it going to be ok ?it runs fine but the dyno guys got me worried telling me its too lean but i reckon he was just trying to get more cash from me

[Eat this 2]

he probably means bigger injectors and/or a remap

[jaysVR6 2]

Is it a stage one or two ZR2? If it's a stage two it should have larger injectors anyway. As for the leaning out at high rpm it will do that to some extent anyway but the dip you see in the fueling at 5,500rpm looks quite a lot imo.

When I had mine mapped at Stealth, Vince told me that it was leaning out slightly and the odd flash up to max rpm would do it no harm, however driving it round a 6000 rpm would kill it (common sense really!!).

Your map looks pretty smooth low down to be fair. But looking at the fueling it's way down (and consistent on both runs) at 5,500rpm when it should be banging in the fuel.

Clarify with them what they will do to your car for the money. £550 for a map is about right if they are gonna do it well.

[gkjnr 0]

its stage one ,would an adjustable fpr sortbthis out tbh i can,t afford spending another 530 quid on it at the moment, the guy said he had the same problem with a 20v turbo and fitting a better pump sorted it

[jaysVR6 2]

4 bar should be enough to be honest. If the engine isn't asking for the extra fuel in the map, simply putting on an adjustable fpr wont solve anything imo.

[gkjnr 0]

so what do you reckon looking at the graph? its running lean low end and top end and i need it mapped to sort it out? i just find it hard to believe that z engineering would sell a kit that runs close to melting pistons afterall they werent cheap kits,could the fact that i,ve moved the maf before the charger be a factor in this?

[gkjnr 0]

another thing i don,t understand is when it does richen up at 5500 the power and torque dip down, why is that should it not go up if its getting more fuel ? then when it starts to lean out above 5500 it picks up and goes again, i might add this is not noticable when driving it, sorry to ask so many questions but i have to bow down to the greater knowledge of you guys and the only way to learn is to ask LOL also i,ve just checked the chart and the printout says the charger was putting out 8.5psi rather than the 6psi it should have would that make a difference?

[xyber 1]

custom remap mate, itll be money well spent, that sudden drop off does look scarey doesnt it

[Phat VR6 3]

They get more power the leaner it is... Its just not safe as you say it melts your pistons.. Overfueling will cause it to splutter and not run nice.. loose power

Pehaps in your case just don't stay in the redline and then asuming you want to change pullys go to a stage 3 pully, Bigger injectors and a map..

That way your not wasting any money and gaining power for the fact you've payed out for bigger injectors and a map

[gkjnr 0]

thats all well and good but i ain,t got the money, i,d try and get it if some of the tuners down south were nearer but tbh i,m not sure about the local guys cos he admitted he,d never done a charged vr before, what i don,t understand about the dropoff is thats when its getting richer and the power dips should it not go up when it richens up rather than down ? tbh i,m not looking for more power just for what i,ve got to be safe and not melt anything i,m getting conflicting opinions on how safe it is now some people reckon its ok but i just don,t know HELP

[Phat VR6 3]

If the mixure it to rich then you will loose power... Not gain power

[gkjnr 0]

so why does it need more fuel then , your gonna have to school me i,m afraid its been all big carbs and cams for me uptil now LOL i can,t get my head round the fact that its running lean but if i do introduce more fuel it will make less power, i take it its got something to do with the timing or has it? would an iffy fpr cause my probs cos it wasnt a new one that was fitted it was the one that was already in the car as its early obd1 and they have a 4 bar reg in them already, or am i missing something and i should have changed that as well

[xyber 1]

its basically a chemical mixture, the 2 components needed to be mixed in the right quantities for the optimum performance, too much oxygen dilutes the fuel, too much fuel and the mixture wont have enough oxygen to make a big enough bang, then at top end when its flying along itll get abit more oxygen into the mix to keep the bang nice and big, like spraying noz into the mix at top end, good for a quick burst to oxiginate the mixture, but too much and it will just be like a blow torch through a piston. A certain company I know of has a rep for bad maps and cooking pistons because it leans off too much.

At the end of the day another £450 for a remap at Stealth or somewhere might seem a nightmare, but its really the only way to make sure its spot on and that your not going to melt anything over time. Better to be pi55ed off about shelling out again, than being pi55ed off coz youve popped your engine and in hindsight you wished it had been sorted

[Phat VR6 3]

Sorry I think ive confused you..

Its only if you inroduce alot more fuel that you will loose power.. As you know theres a perfix fuel to air mixure that gives good power while keeping your engine safe (147.1)... And the more revs and more air the more fuel required

Im sure that when they say its running abit lean there talking about the fact that more fuel on tick and high revs would be nice to make sure you don't damage anythink.. Nothink to do with gaining more power. I think there talking about that big dip at 5500 rpm on the AFR graph.. Not the BHP or torgue graff.. put that probaly does exsplane the small dip at 5500 rpm on the bhp graph as that probaly is too little fuel and would cause a loss in power

Like when your running in a 2 stroke motor bike you run them rich and with more oil.. They not very fast and feel sluggis... not running smooth... Once run in you use less oil and less fuel and as a result you gain quite alot more power..

As said above the dip in power looks like its somthink todo with the map and im guessing that once you got the fueling sorted on the tick over and full throttel your not going to gain any more power... Just have a safer engine

[gkjnr 0]

so going to a adjustablr fpr isnt going to cure it then? and going to stealth isnt an option i,m afraid as i live in central scotland

[jaysVR6 2]

The fueling (3rd Graph) is dropping right off at the point the Power and Torque curves dip my friend.

The only way is to have the car mapped correctly, there are no fast and easy solutions im afraid, carry on as you are and you're risking damaging something, end of story.

Oh and your gonna need bigger injectors running 8.5psi, no doubt about it, along with water injection, the car will detonate badly without any further cooling at that sort of boost.

Go and see Vince or another recommended tuner local to you who has experience tuning supercharged VR6's, they will perform the job correctly and with that sort of psi, you should see around 270-280hp no doubt about it.

If you can't afford to do it, don't drive it hard until you can, plain and simple - either that or don't drive it at all.

[Phat VR6 3]

The reason it looks like its somthink to do with the map is because of that big dip at 5500 rpm but at 6000 rpm the injectors are still been able to produce the fuel.. The graph doesn't show tickover so you can't say

If you got it to say 13 from 5500 to 6000 then not only would be be more safe but that small dip in power on your BHP graph would probaly disserper aswell

I think if you managed to keep it at 14 (perfix air to fuel) all the way across then you would produce even more power across the rev range

But as to if there trying to get more money there not i don't think.. I wouldn't be to happy about that sharp dip at 5500rmp.. If it would cause damage or not is hard to say.. Theres only one way to find out. Damage from running lean however usally happends if your running 2 fuel pumps and one gives in.. causing it to run very lean

[gkjnr 0]

oh well that,ll be that then i don,t know why its putting out 8.5 psi as it should only be 6 psi i take it the fuelling is controlled by the map then and z engineering have got it wrong? i have a giac chip as well that was supposedly for a car with a dizzy but that was the one the guy ran in his corrado i wonder if that would be better , i suppose the only way to tell uis by having another power run done and thats another £85

[Phat VR6 3]

I donno but C2 might still make chips for chargers.

I think if you got a chip for 6 psi yet your running 8.5psi then that would cause your afr to drop off like that because your adding more air than the chip thinks.. causing it to run leaner than it should be??

You could try having a word with z enginnering if its a new kit.. get them to send you another chip to try

[jaysVR6 2]

Be under no illusions buddy, screwing around with a car that didn't come from the factory with a supercharger is no cheap hobby. Some people are lucky, some run into trouble throughout the cars life.

You'll get nowhere throwing money at it. Whats a trip down south going to cost you in the long run?

You know what i'd do, I'd give Vince a ring, tell him your situation and email him the graphs, you can then work out a plan. He's very personable and will help you out. That way you can work things out sensibly, with someone who is an expert in their field, rather than chucking money down the drain chasing a problem you know little about.

[gkjnr 0]

yea but that was the chip that came with the kit, but to my knowledge the guy i bought the kit from used the giac chip and not the zengineering one , will a chip for a dizzy motor be different to one with a coilpack?