4722 replies to this topic

[Nev]

Nev

Did you ever do a compression test?

I think you need a trip to specsavers - read paragraph 3 again ! Yes I did, but the damn thing have different readings every time I used it, so I gave up. If someone near Bristol had an accurate one I'd be keen to borrow it and have another bash.

Edited by Nev, 11 April 2013 - 05:03 PM.

[cnrandall]

You need to do a leak down test.

[oakmere]

Sorry Nev Missed that whole paragraph reading on my phone. Did you remove the TB to allow the engine to breath? Cheap one worked for me loaned from my local garage.

Edited by oakmere, 11 April 2013 - 06:15 PM.

[completechip]

Nev, 2 things: 1. Try to put back the oil vapour return pipe , plug it back into the air intake. this way you will ventilate the crankcase more easily and you'll get rid of the positive pressurre. 2. Keep in mind that you will need software adjustment after forged pistons installation. why? Because they tend to 'clap' more than usual pistons due to different expanding coefficient and these pistons being noisier than usual,will mess knock sensor readings...the sensor sensitivity must be readjusted. I would carry out a compression test.

[steveboyslim]

Nev, 2 things:
1. Try to put back the oil vapour return pipe , plug it back into the air intake. this way you will ventilate the crankcase more easily and you'll get rid of the positive pressurre.

2. Keep in mind that you will need software adjustment after forged pistons installation. why? Because they tend to 'clap' more than usual pistons due to different expanding coefficient and these pistons being noisier than usual,will mess knock sensor readings...the sensor sensitivity must be readjusted.

I would carry out a compression test.

Piston slap when the engine is cold has never been a problem with these and other engines using a knock sensor as any extra 'noise' (vibration) is still within the design perameters of the original ecu map, when the engine is warm and piston slap is almost reduced to nothing.
The Omega pistons I would supply will give similar compression ratio as the machined Mahles so no 'software' adjustments will be needed (although I feel a better job of re-mapping Nev's engine will vastly improve drivability and power)
The Omegas are the some of the quietest forged pistons I have used and are used in several 600+bhp CLET engine (one 700+bhp) and several 600+bhp ZLET/LEH engines.
I did suggest borescoping the engine or compression test or leak down test.
The standard engine managment is designed to run closed loop (emissions) so venting the crankcase breather to the air intake (especially if before the airflow meter may not be such a good idea.

Steve

[completechip]

I am not reffering to engine when it's cold...it's easy to raise temperature threshold for knock detection, so knock control will become active once engine is warmer than usual configuration. If pistons are ok, the slap will be next to nothing and at that point it's no problem indeed. But some of the pistons have enough play even when engine it's warm. So believe me they mess up knock sensor readings. I've seen this especially on JE Pistons on 1.8T VAG's. Never encountered on Z20LET but still possible. But on Nev's electronics it's a 5min job to readjust sensitivity, although several precautions must be taken. Anyway the knock detection from factory is very conservative and takes away a lot of performance so you can easily raise the sensitivity without taking too much risk. Indeed if blow-by phenomenon is excessive, venting the crankcase into the air intake is not ok. But if engine is ok, I cannot see why it would be wrong since it's done from the factory like this.

[steveboyslim]

I am not reffering to engine when it's cold...it's easy to raise temperature threshold for knock detection, so knock control will become active once engine is warmer than usual configuration. If pistons are ok, the slap will be next to nothing and at that point it's no problem indeed. But some of the pistons have enough play even when engine it's warm. So believe me they mess up knock sensor readings. I've seen this especially on JE Pistons on 1.8T VAG's. Never encountered on Z20LET but still possible.

But on Nev's electronics it's a 5min job to readjust sensitivity, although several precautions must be taken. Anyway the knock detection from factory is very conservative and takes away a lot of performance so you can easily raise the sensitivity without taking too much risk.

Indeed if blow-by phenomenon is excessive, venting the crankcase into the air intake is not ok. But if engine is ok, I cannot see why it would be wrong since it's done from the factory like this.

I have a friend with a 450+ bhp converted 1.8T VAG (converted to 2.0) using JE pistons in the back of a Lotus without any problems.
The idea of extra piston to bore clearance is to counter the expansion rate of the forged piston so if you have piston slap when the engine is warm something is wrong, incorrectly bored or piston skirt wear or shrinkage (I have measured nearly 0.5mm shrinkage after less than 1k miles and returned the pistons to JE)
Even so you have quoted the reason I no longer use JE pistons although there are many of this type of engine which use them on standard managment without problems with the knock sensor.
I have seen modified cam shafts cause knock sensor problems, again not with this engine.
Omega pistons do not piston slap, shrinkage or wear problems which is why I use and sell them.
The biggest problem with Omega, is that as a company they are hard work to deal with.
The best thing Nev can do is bin the standard engine managment and replace it with something more easier to live map.

Steve

Edited by steveboyslim, 12 April 2013 - 07:14 AM.

[cnrandall]

^^^^ bang on the money ^^^^ A really good standalone ECU will do a much, much better job of looking after the engine. The syvecs unit I use has fully configurable single cylinder knock control which allows me to run right up to the knock limit in complete confidence. At the rebuild last year after three years of racing and probably 1000 dyno pulls the pistons went back into the same bores and that's down to good engine control and good mapping.

[Duncan VXR]

When going to these levels standalone is a no brainer as both Steve and Chris confirm - soooooo much better control and setup DG

[completechip]

Can you post more details about this stand alone that supports knock detection?

[siztenboots]

perhaps a thread of its own

[slindborg]

tbh the OEM ecu is more than capable of doing what you ask of it, its just that as ever with 'remaps' they havent got full documentation/support/access to all the calibration etc and they simply cannot do the required job properly.

[cnrandall]

Can you post more details about this stand alone that supports knock detection?

http://www.syvecs.co.uk

[Nev]

Thanks for all the comments. I've just bought a leak down test tool. Hopefully it will work better than the compression tester I bought.

Edited by Nev, 12 April 2013 - 11:53 AM.

[completechip]

My car was fitted with Haltech Platinum Series 1000 when I got it, and I swapped it for OE electronics just because I could not trust this stand alone ecu, could not monitor the detonations and ex-tuner went -10 degrees advance and + many many % on fuelling just to keep things on safe side. Car developed 356hp at 1.6bar with Haltech, now it develops 430hp at 1.5bar on standard electronics. Main problem I encountered is related to poor hardware design of the original Me1.5.5 ecu, so far I've broken 2 ecu's just because battery went dead at a certain moment, and the last one made the car run like crap with no DTC's, but fuelling and ignition were messed up because of internal fault of ecu. If there is a stand alone with fully knock detection equipment fitted, I would be glad to study this setup.

[cnrandall]

My car was fitted with Haltech Platinum Series 1000 when I got it, and I swapped it for OE electronics just because I could not trust this stand alone ecu, could not monitor the detonations and ex-tuner went -10 degrees advance and + many many % on fuelling just to keep things on safe side. Car developed 356hp at 1.6bar with Haltech, now it develops 430hp at 1.5bar on standard electronics. Main problem I encountered is related to poor hardware design of the original Me1.5.5 ecu, so far I've broken 2 ecu's just because battery went dead at a certain moment, and the last one made the car run like crap with no DTC's, but fuelling and ignition were messed up because of internal fault of ecu.

If there is a stand alone with fully knock detection equipment fitted, I would be glad to study this setup.

Go on the syvecs website and download the software, its free. Its awesome stuff, the knock control is very, very, very good and that's only the start of it.

[Nev]

Blimey, just received the turbo back from CR Turbos. That was a bloody fast turn around time, if only the rest of the motor industry were this professional... The spindle seems a lot more firmly seated now (both laterally and back and forth on the plane of the CHRA). The guys said it had a moderate amount of carbonisation on the spindle where the oil had escaped on the turbine side. Now I just need to wait for the leak down test kit, hopefully this will clinch the evidence and let me know what step to take next.

Edited by Nev, 12 April 2013 - 12:45 PM.

[steveboyslim]

tbh the OEM ecu is more than capable of doing what you ask of it, its just that as ever with 'remaps' they havent got full documentation/support/access to all the calibration etc and they simply cannot do the required job properly.

You have to work with the tools available, if you cannot get all the documentation/support/access to calibration that make the ecu not usable even if is the best ecu in the world.
From what I have been told and experienced the standard ecu cannot be live mapped making re-mapping very time consumming.

Steve

[completechip]

Indeed Me1.5.5 does not support an emulator like OLS300 as it is a hybrid ecu and it does not have 29F flash which could be emulated, thus making life a lot easier...

[Nev]

I'd love to be able to live map and even have a friend who maps regularily who would help me Im sure. It's just the cost of outlaying the dosh on what is already a very expensive project. I'm also keen on TC, a genuine car + life saver which is part of the Syvecs bundle as well as binning the MAF as I think it is the main reason for my lumpy idle.

Edited by Nev, 12 April 2013 - 06:38 PM.