Eric_Oz_S2

Done.

First start tomorrow.

Rogue_Ant

Looks great!
Keep us updated, and I am definitely curious about how the tuning goes!

Eric_Oz_S2

Got it running today - first test drive. I took it fairly easy but there does seem to be some belt slip as I'm only getting around 3psi boost from 4500 up, and pulleys feel quite hot (although no slip noises). I can notice the additional power - though due to the low boost it isn't a massive improvement. I'll need to find a larger idler pulley as the 60mm one I am using combined with the belt and tensioner adjustment doesn't quite get the belt tight enough. Probably need a 62/63mm one. I think some Toyotas use that size? I need to get logs with the current large 100mm SC pulley first so I can work out the optimum pulley size.

Not sure if I should use belt grip on the micro-v belt as it may make a mess of the belts and pulleys - what do you think?

AFRs are conservative at the moment as I set the fuel map expecting 6psi boost so around 10.5-11 at WOT. Driveability so far is almost perfect (probably what you may expect with only 3psi boost!)

Dubai944

Belt grip helps but it won't make up for a lack of pulley wrap if that's your current issue and it does tend to spray around a bit and leave you a sticky residue in hard to reach places. Make sure the belt is nice and tight!

Eric_Oz_S2

Belt adjustment is at maximum and one belt size smaller is just too tight to get on. Pulley wrap is 180 degrees for crankshaft and SC and about 45 degrees for alternator. Slip seems to have reduced - but still relatively low boost (3.5 psi). I think I'll drop pulley size down from 100mm to 80mm to spin the SC at max RPM.

Dubai944

It could simply be your pulley size, as you say. Belt slip is hard to detect though.

Although it can be a bit messy, belt grip spray is useful for checking for slip because you will generally always get a bit of a boost increase from belt grip spray if there is any slip going on, even if you can't hear or see any slip.

Cross cutting also can make a big difference. I went from 7 to 9lbs boost without changing pulleys on an earlier setup just by cross cutting the pulley.

If you get no improvement from spray or cross cutting then you know it is something else, most likely pulley sizes.

Eric_Oz_S2

Dubai,

Thanks. If I take the belt off to spray, do you think it will result in a mess on the pulleys and eventually damage the belt? The CRC stuff says not to be used on multi v belts. Did you have to clean the pulleys o9ff when you used it and replaced belts?

Dubai944

It shouldn't cause any belt or pulley damage, it usually wears off fairly quickly. If you spray the belt off the car you will minimise the mess. But honestly for a quick check, if you can get at the belt easily, give it a spray while it's idling - just aim at one spot and let the belt run through the spray for a few seconds. Easier than dismantling.

Eric_Oz_S2

I'm fairly sure it is pulley size as the 968 D1R kit uses a 90mm pulley to get 5psi boost (no IC). I'll run an 80mm and hopefully end up with 6psi.

Dubai944

6psi should make a decent difference, hope it works out for you.

I will be back from Dubai in March so hope to get to my car out to some Porsche Club events after that to clear out the cobwebs and get it set up for some QRDC races later in the year.

Look forward to seeing your car working well by then!

Eric_Oz_S2

I ran with some belt grip and there wasn't much chsange - good to know though.

Here is a log of a WOT 3rd gear run. Max boost measured at intake manifold is 128kpa or about 4psi. I'm guessing that works out at about 250 fwhp ((210*1.27)=267hp -17 losses) allowing for some SC drive loss. What do you think?

Looking at the Rotrex maps, if I run an 80mm pulley this should add about another 20%, so probably about 300fwhp. Target is actually 295hp (class rules - or add some ballast).



You can see it is running very rich in the midrange - note that this was generated using the cat delete map in the DME with additional fuel trim (so no o2 adjustment). I'll now have to remove some in the mid and add a bit at the top end. I guess AFRs of about 12.0 to 12.5 should be OK when on boost? I'll then need to do this again with the lambda maps as the adaptation maps also change the WOT maps. Still some work to do.

Rogue_Ant

Very cool. Yep, definitely fat in the mid-range.. but better than being lean!
12.0-12.5 is a good target at peak boost. Once it WOT, I would immediately target ~12.8 and then slowly slope down as boost rises.

Dubai944

Do PCQ actually get you to dyno the car for classification?

Eric_Oz_S2

If it has been modified then it needs to be dyno'd sometime during the competition year. In my case I will make an assumption of power to weight and get it dyno'd to verify the power (once smaller pulley in). Stock cars don't normally need to be dyno'd.

Race cars are normally put in open class. You can check the rules on the web.

Paulyy

that's some nice work you've done there Eric!

Where did you pick up the oil cooler from? And are you running the stock oil cooler also (assuming it's the same as the turbo)?