488 replies to this topic

[CHILL Gone DUTCH]

I wouldent worry about short term fuel trims which are + 8 to -8% as this can change in weather conditions and shows the Ecu is coping with differences from the base map it's when these figures are getting above 15-20% +- you should be more worried as it indicates the learning is very poor

[CHILL Gone DUTCH]

Wideband is always best to get fuel right Be sure when using a wideband the the delay time is correct as this can make it impossible to get the fueling correct at a given Rev/time

[CHILL Gone DUTCH]

As for the fuel pump or injectors not coping Look for higher duty cycles but you need to know what a healthy duty cycle should be for your setup before noticing this Again wideband is a good indicator of pump issues as car starts to run lean Also look at massive peaks in the fuel tables fuel trims etc You won't get continuous high Rev running while fuel learning but once it's fuel learned carry out logs with long higher revs running logs check for evidence that things are not the same as shorter high Rev runs But you have to take in to account temps

[Exmantaa]

 

My experience is that injectors give a high % duty cycles over 6.5k rpm on basemap.

As the software cannot correct over 3.5k isch without a wideband, you will be stuck with rich fueling higher up the band.

(my peak went from 100% to 84% after 1 wideband correction run)

 

How are the duty cycles on high rpm atm?

 

 

 

What makes you say the software can't correct above 3.5 k?

 

My understanding is that it can correct, however as you have to run in open loop so risk damaging the engine if the fuel trim is significantly different to target. Obviously the potential for deviation from target increases with power output making people with high power more at risk.

 

I'm measuring duty cycles this week, priority so far has been getting the car running properly.

 

 

OBD can/will correct above 3.6K, bust as you said the engine is simply put in open loop and targets a 14.7AFR (narrowband O2) over the whole load range. Each cell is then corrected with the measured  short + long term fuel trim value.

But you risk your engine when boosted high, as the heat load will be immense without the extra fuel cooling...

And as most modified-SC engines learned this way seem to run very rich up top, there probably is some error on the safe side with the algorithm Peter uses to fill in the complete fuel map. => use/borrow a wideband to make the final adjustments on higher loads.  

[fezzasus]

Minor update, hopefully with some more in a day or two.

 

Last Saturday saw the clam come off again, for the following;

 

- Replace boot release cable (mixture of heat and rust had killed the previous one)

- Fit a Provent 200 for PCV filtration

- Fit a manifold heats hield

 

Boot release

 

Used 1.5 mm diameter release cable (same as OEM) and new sheath. Need approx 2.5 M. The cable can be run from the cabin side (no need to drop fuel tank). Silicone spray is your friend when fitting.

 

Heat shield

 

As much as I like the look of the Tullett manifold, the heat was pretty bad, the boot release cable had melted and the boot was starting to blister. Simplest option was the following, mounted using stainless bolts into the original heat shield mounting points.

 

 

PCV

 

Already sick of the smell from venting the crankcase to atmosphere, so mounted the Provent 200 to the bulkhead by the air filter. Haven't got all the plumbing yet but will look approximately like this:

 

- CC gasses exit rocker cover via 13 mm barb. Goes into 13 mm 180 degree silicone bend to route to the rear of the engine. Enlarged to 19 mm using straight silicone reducer, 90 degree silicone bend at top of engine, follow injector loom along back of engine to a 25-19 mm 90 degree reducer into the Provent.

 

- fresh air out of Provent into 25 mm T piece on 76 mm air intake pipe before supercharger.

 

 

As soon as the T piece turns up i'll have this all working.

[fezzasus]

I've covered about 300 miles now but still suffering from a bit of clutch slip. Appears to be improving but it makes overtakes pretty frustrating. Has anyone else experienced slip on a new clutch? How long did it last? I'm starting to think that picking a standard Z22SE clutch as a replacement was a bad idea (despite no issue with my old clutch)

[CHILL Gone DUTCH]

Would of thought you should get a way with standard clutch on stage 2 quite easily Anything above it might well be a other storey

[fezzasus]

Would of thought you should get a way with standard clutch on stage 2 quite easily Anything above it might well be a other storey

 

That was my thinking, although I expect to be closer to 280-290 bhp with the 2.0 L engine now i'm running different cams and not limited to 250 by the rods.

[CHILL Gone DUTCH]

Sounds like the clutch may be on its limits Tom Hope it gets better

[fezzasus]

Sounds like the clutch may be on its limits Tom Hope it gets better

 

So do I, don't fancy taking the engine out again.

 

I'll make a decision by 500 miles of running. 

[Exmantaa]

I've covered about 300 miles now but still suffering from a bit of clutch slip. Appears to be improving but it makes overtakes pretty frustrating. Has anyone else experienced slip on a new clutch? How long did it last? I'm starting to think that picking a standard Z22SE clutch as a replacement was a bad idea (despite no issue with my old clutch)

 

Had the same with my Harrop and it became better in time. So give the new clutch some time to bed in, but be carefull not to burn it to pieces

[Doctor Ed]

a new clutch might grab, be chatty, or otherwise be a bit harsh, but it shouldnt slip! the bed-in time simply deglazes the faces, and matches the surfaces to each other. it makes the clutch nicer to use, smoother, and quieter. it should have next to no impact on the holding torque* if its been slipping from the get-go, and still slips after 300miles (!) i reckon youre outta luck and the clutch is either toast, wrongly installed, or the wrong spec for your requirements *excpet for the first handful of engage cycles

Edited by Doctor Ed, 08 August 2016 - 01:02 PM.

[gaffer1986]

I've had new clutches before and as long as th the flywheel was also replaced the car went back to feeling new again. I'm a driving instructor so I do use them.

Edited by gaffer1986, 08 August 2016 - 02:36 PM.

[fezzasus]

Thanks for all the comments. Some useful food for thought there. I think it makes sense to keep running the current set up for a couple more hundred miles to see what happens before jumping on something else.

 

Clutch and clutch plate are standard Z22SE parts (new old stock). Flywheel is lightweight batch from Matt Bentley group buy. If I do have to change it out, what recommendations do people have? Should I consider a C20XE clutch and plate? Something more exotic?

 

 

[vocky]

some flywheels have a weird coating on them, which usually wears off.

 

 

[oakmere]

When I rebuilt my engine I replaced the clutch with oem LUK. I ran the engine in lots of on off acceleration to bed the Pistons. I then got a massive clutch slip and thought bollocks. But it is still going 10k later. I find with the lightweight fly it is very easy to over slip the clutch as the revs rise much quicker. Give it some time and be gentle with it for a few hundred miles and see if it starts getting better.

[fezzasus]

Next job

[gaffer1986]

What is it?

[Sticky]

What is it?

Fuel pump

[gaffer1986]

I see, looks like something you find in a washing machine.