Odd RR results. Can anyone diagnose?

[S2central.net]

The flames will be side effect of richness alright - especially so as you are deCATTed.

Might be worth checking your fuel pressure regulator - you should see 4bar on the rail, less whatever vacuum it pulls if testing on idle of course.

Fuel pressure should be 4bar ABOVE manifold pressure at all times... MIght be worth getting injectors checked out too. If they aren't flowing properly or turning off too slowly then your getting more fuel than you should.

MAFs are tricky beasts - they normally degrade in such a way that they produce lower indications of the amount of air coming into engine... WHich is OK in cruise as the closed loop lambda system corrects mixture for that (within limits). On WOT, lamdba is ignored and so you should be injecting less fuel than required air. So its weird that you seem rich.

Then again - you say it drives fine and was not massively outrun by a similar spec car (you are heavier for starters) so its odd the dyno result doesn't back that up.

COuld the intake temps be very high on the rollers ?

Paul

[Animal Mother]

The flames will be side effect of richness alright - especially so as you are deCATTed.

THought so, cool though!

Might be worth checking your fuel pressure regulator - you should see 4bar on the rail, less whatever vacuum it pulls if testing on idle of course. Fuel pressure should be 4bar ABOVE manifold pressure at all times... MIght be worth getting injectors checked out too. If they aren't flowing properly or turning off too slowly then your getting more fuel than you should.

How do I test that? VAGCom? I can't seem to find out much more than Engine codes with VAGCom.

MAFs are tricky beasts - they normally degrade in such a way that they produce lower indications of the amount of air coming into engine... WHich is OK in cruise as the closed loop lambda system corrects mixture for that (within limits). On WOT, lamdba is ignored and so you should be injecting less fuel than required air. So its weird that you seem rich.

How accurate are your multimeter tests on your website? Will be tring them first I think.

Then again - you say it drives fine and was not massively outrun by a similar spec car (you are heavier for starters) so its odd the dyno result doesn't back that up.

Thought so too. As I said the runs were inconsistent, esp. between runs 1&3 and run 2. Everone elses were quite consistent though.

Could the intake temps be very high on the rollers?

Cold day with big blower fan but heat soak was mentioned by the guys running it.

[GazzaG60]

there was quite some heatsoak. thats was evident in the drop in hp per run

id say too rich.

the graphs were peak not average.

[newsh]

Ah, rich, that makes more sense, very likely an air leak then, somewhere after the turbo. Do you have the Mark H Mod?

[Animal Mother]

Ah, rich, that makes more sense, very likely an air leak then, somewhere after the turbo. Do you have the Mark H Mod?

Don't reckon its a leak after the turbo (boost leak?) as I'm boosting to 1.5bar.

What is a Mark H mod? The car is standard apart from a S2Central homefry, 3" cat bypass and a foam panel filter.

[Rusty]

BOOST LEAK!

AFR screams boost leak to me. Fits with a run I had done back in August. Best get a boost leak test kit and start hunting the wee ******s down. Flames are a classic sign of this too, NIP's car was doing the same on the way to Weston in the summer and we diagnosed a faulty Forge DV as the culprit. Fitted a 710N and he got 288bhp.

Your setup should run between 280 and 290, more if it's like mine and just runs 'right',

Basic rule of thumb is that you do a boost leak test before going to a RR sessio otherwise you're more than likely going to waste £50. BTDT a few times!

[Acidburn]

I'd check that still tho as with mine I still found it leaking even tho it was boosting at very nearly what it should do when I picked the car up. Always best to be sure.

MarkH mod is a small samco style hose that sits between the intercooler and crossmember at the front of the engine bay on the passenger end of the intercooler. I'm not sure where the ic sits on yours if its at the front or the side?

[GazzaG60]

i doubt a boost leak. 1.5 bar aint no leak otherwise we would be lookinga t a 2bar chip.

the flames sound like fuel cut aint there.

personally when i saw it run id say it was pretty good and a tad rich on boost. about right. remember 10% in the rollers and you would be on target.

this is one of the issues with remaps. every car is different so a generic chip isn't always sucessful.

good day had and a good basepoint to move on from.

where are we putting the graphs and pics

[Acidburn]

Mines in psi but I noticed mine was running normally between 20-23 and with my leak I was getting 18 ish at best.

[GazzaG60]

i stand corrected maybe a couple of psi which at those levels or RPM will be the difference between 12:1 or so and 10-10.5

[Rusty]

Mine was running fine with a boost leak but the AFRs identified it. One of the Smacos had de-laminated and the jubilee clip fallen off. No overboost protection, no drop in boost but a leak was occuring.

[Acidburn]

Mine still seemed to run ok but I noticed it getting worse and worse over the space of a couple of days, turned out the back hose that joins the inlet,idle was slightly split on the underneath. I used a jubilee to hold it together at the EA meet till I got home, we had noticed some residue across the spark plug cover which indicated this.

@AM - when your driving it what sort of noises apart from the exhaust can you hear? any noises like the turbo spooling up etc?

[Animal Mother]

i stand corrected maybe a couple of psi which at those levels or RPM will be the difference between 12:1 or so and 10-10.5

Does anyone fancy doing a boost leak test on my car then?

Might change the MAF (after testing) as I can get one for £80 anyway.

Can I have more info on the Mark H mod please? Where, what and why? IC is offside lower bumper vent BTW.

[Acidburn]

http://cgi.ebay.co.uk/STRAIGHT-REDUC...QQcmdZViewItem

Not sure if yours is the same as s2's but we use a bit of hose like this to fit between the intercooler and crossmember (needs cutting down but easy enough) and replaces the o-ring that sits between and normally breaks down.

[Rusty]

AM, just seen you're running a URS6... I don't think the Mark H mod applies so don't worry too much. What does apply is a boost leak test, not sure where you can get one done but AndyP will sell you a bung that replaces the MAF and blanks off the breather, you can pressurise it from there. Do it somewhere quiet as you'll have to try and hear the leaks!