Motec M4 question

[Guest Andrew]

Hi -

We had the turbo on the dyno yesterday - there is a problem with either;

A.) The mechanical side of the boost controller

B.) The ECU map.

The car whacked out 156 kW to the rear wheels at around 4000 rpm - then proceded to have random power outputs after that (will post dyno graph ASAP).

Basically boost comes on nicely - then fluctuates rapidly between 13/15 psi - and the power curve follows this.

Boost is controlled by an internal wastegate that is controlled by this little pressure switch thing which is hooked up to the ECU. Is there any way to test the pressure switch thingee? (Will get pics soon) I'll take the waste gate off and check it's all sweet - but it seems to be doing it's job. Car is running rich - around 11:1 - occasionally dipped into the high 10s.

Regarding the motec - we had trouble getting the dyno to get a decent RPM reading - ended up using the inductive type sensor (which still gave spastic readings).

Also - connecting the Motec to the PC revealed a problem - the ECU firmware is a slightly older version than current - so it doesn't talk to the ECU. Will upgrading the ECU software delete the map that is already in there?

I'm not stopping till i see at least 210 kW at wheels - Gavin Bellars (hivelocity.co.nz) reckons we'll see around 165/170 rwkW on 14 psi with a good tune - so hopefully we'll get badass power with 18psi

One last thing - the boost gauge reads 15/20psi - haven't looked where it's getting its signal from - but the dyno was only measuring 14psi (signal from near fuel pressure regulator).

Chur

[Guest Andrew]

Just spoke to the Motec distributor - 850 bucks to turn on wideband oxy sensor!

[drifty325i 0]

Just spoke to the Motec distributor - 850 bucks to turn on wideband oxy sensor!

Dang! but it has to be done i guess. I love that car dam u!

[318isCoupe 0]

If in it's current tune it's running rich then chances are it was tuned to run more boost than what you're putting through at the moment. Any idea about what levels it had been running before?

[Guest Andrew]

Had heard 20+ psi.

I've got the dyno graph here

[conrod 1]

Andrew, that steep climb in the power curve before it flattens off, is just the effect the turbo has as it comes onto boost, tuning the car will not change that dramatically. The wobbly parts in the power graph look a bit odd, not sure what is causing that, maybe the wastegate actuator pulsing (ie duty cycle from the Motec to the solenoid not fast enough, causing it to open and shut continuosly) 11:1 AFR not THAT rich for a turbo either.

[Guest Andrew]

Andrew, that steep climb in the power curve before it flattens off, is just the effect the turbo has as it comes onto boost, tuning the car will not change that dramatically. The wobbly parts in the power graph look a bit odd, not sure what is causing that, maybe the wastegate actuator pulsing (ie duty cycle from the Motec to the solenoid not fast enough, causing it to open and shut continuosly) 11:1 AFR not THAT rich for a turbo either.

What is the easiest way to test the signal from the motec?

How much more boost do you reckon I can safely run? I was waiting to see what temp the intake air is - then see if we could up the boost and perhaps increase the size of the intercooler.

[E30-323ti 66]

What is the easiest way to test the signal from the motec?

How much more boost do you reckon I can safely run? I was waiting to see what temp the intake air is - then see if we could up the boost and perhaps increase the size of the intercooler.

I gather you didn't do a run with the boost control solenoid bypassed to see if it was a actuator issue??

What did the ignition curve look like?? Load signal (Map and/or TPS)??

You can tune the engine to get boost quicker, Ignition & cam timing, but I imagine it would be pretty close to optimum in it's current state, unless it's fallen "out of tune" somehow????

[hybrid 1043]

You got connectivity to the laptop yet ?

First thing no point assing around with it until you get wide band opened up. Then look for leaks. Then mechanical.

[Assault 3]

If in it's current tune it's running rich then chances are it was tuned to run more boost than what you're putting through at the moment. Any idea about what levels it had been running before?

As this system will be based on Manifold Air Pressure, it will be tuned as RPM vs Boost essentially so running more boost will not change the fact that it is running rich at 14psi. From what I understand the ECU is not tuned for this engine as it was tuned for the previous engine which has now been replaced. So, Retuning and setting up your boost control maps will sort out the problems.

[Assault 3]

I gather you didn't do a run with the boost control solenoid bypassed to see if it was a actuator issue??

The wastegate actuator would probably have an opening pressure of around 8psi or so, at a guess, without any boost control solenoids so it would probably be an inconclusive test to run it with the solenoid bypassed unless you used something like a manual boost controller to up the boost, but even then its unlikely the manual boost controller would be stable.

Plumbing the boost gauge from the Plenum/intake manifold would be a good place to start and ensure the Motec is plumbed from there too. As conrod said, some adjustment of the boost control duty cycle may help the fluctuations.

Getting the Wideband unlocked would be a nice help if you are gonna tune it yourself. EGT and Knock monitoring would also help alot if you want to get a good tune so maybe some Motec tuning on the Dyno would be the go.

Edited November 3, 2006 by Assault

[SRBMW 6]

Hey andrew

Those wastegates solinoids can usually be plumbed two ways for internal external maybe check here first.

On factory turbos usually the boost source is from the front cover so then the actuator recieves exactly the boost the turbo is making however once the boost goes through the cooler piping etc and reaches the plenum it usually drops a couple of psi which can show differences on the gauge which arent usually that accurate anyway.But if the computer is getting a different boost(lower) reading to the acutator somes it can make the solinoid cylcle and cause fluctuantion like that.a good test is to run the boost feed for the ecu and wastegate actuator from a similar area this usually increases performance on factory turbo cars.

Good luck

[Assault 3]

Hey andrew

Those wastegates solinoids can usually be plumbed two ways for internal external maybe check here first.

On factory turbos usually the boost source is from the front cover so then the actuator recieves exactly the boost the turbo is making however once the boost goes through the cooler piping etc and reaches the plenum it usually drops a couple of psi which can show differences on the gauge which arent usually that accurate anyway.But if the computer is getting a different boost(lower) reading to the acutator somes it can make the solinoid cylcle and cause fluctuantion like that.a good test is to run the boost feed for the ecu and wastegate actuator from a similar area this usually increases performance on factory turbo cars.

Good luck

Good point, there is a different way to connect up some boost solenoids for boost controllers on external wastegates and I've seen several people set them up wrong. Its not a hard mistake to make either. I can check it over if you like, give josh a call or something.

[Guest Andrew]

Anyway - took it to the drags, it can do a high 13 if I don't n00b up so much. Did a 14 flat with 165 kph trap speed.

We hooked the laptop up and found some interesting things.

Injectors are at 100% duty cycle! There is an overboost warning on the ECU also. (220 kpa is what it recorded - 30ish psi! There is no way the boost gauge/or the dyno for that matter recorded a reading like that)

I don't understand how boost control is happening - the ECU gives that pressure switch a signal of 90 Hz - i'm not sure how to translate this into any 'real' to work out what boost it is giving.

What injectors should I get? Any more info on this boost control?

Can hook up pics of how the wastegate is hooked up.

If anyone is interested I can upload the map.

Cheers

[SRBMW 6]

I've found in the past too smaller wastgates can't control the boost as well as you want it and too bigger wastegates combined with a turbo that can't keep up can cause boost to drop off.

You need to figure out what style injectors they are top feed(most probably)which has the fuel coming in from the top and then theres side feed which you probably dont have,if you pull one of your injectors then you can go looking for something that will fit in with out too much hassle good thing about the motec is you will be able to run different impedance injectors either high or low a good idea would be to get an adjustable fuel regulator aswell,

I'd say 500-550cc injectors are a good place to start(evo rx7s).Also motec's are usually capabale of running big injectors quite well so you may aswell plan bigger for the future so maybe 600cc.Take your injector out and give petrojet I think a call go in and see what has similar dimesions,Most of the time its best to buy new injectors as the cost of buying secondhand ones and having them cleaned is not really much cheaper than buying the new ones and they never really get all the dirt out when they clean them!!Check motec site for diagrams for the boost control solinoid

Darren

[conrod 1]

From memory that car had Bosch 803's, and although I don't know the flow rate, they are fitted standard to a lot of Porsches, including 944 Turbo, and will support 340hp in an Escort Cosworth, so firstly I would perform a fuel flow test to make sure there is an adequate supply. High 13's on a drag strip would suggest close to 300hp in a car of that weight on road tyres, so that doesn't sound far off the mark.

I have some Bosch 403 injectors, which are Motorsport parts and are much bigger, there are also some very good Siemens ones available now, with very good spray patterns, high flow rates and are very reasonably piced.

[Guest Andrew]

Noob error - I forgot atmo pressure was 100 kpa.. so the overboost is being flagged at anything over 220 kpa (it hit 222 kpa - nothing to worry about).

Conrod: What is the best way to do that test? Do you know what fuel pump the car has?

I didn't find injectors that expensive (new) when I got them for the racecar. Darren - if you've got some free time I should swing by and you can have a looksie.

Cheers

[SRBMW 6]

Another thing you could do is buy a three port tee from enzed or something and have fittings coming out of it and tap a fuel pressure gauge(autoquip marketing next to segedins dominion road $50??) into the third port and run inline to makesure you are getting good pressure but the 100% duty cycle is concerning,got an exam monday but give me a call 021164563

Darren

[mops 4]

yeach, or just get the fuel rail our, and on the end of it, weld up a fitting (it will need to be tig welded), and then there's a dude on TM selling cheap pressure gauges of various ranges, that's what i would do

[Assault 3]

What fuel pump is it running and what fuel pressure regulator? Base fuel pressure needs to be checked. If those injectors are rated at about 340hp then the duty cycle shouldnt be getting maxed out. Not for only 210HP at the wheels anyway, I doubt there'd be much more than 50hp difference between engine and wheel HP so they should be adequate for what you are running. Looks like your boost control needs to be tuned properley and your boost limit raised a bit.