2JZGTE E32 Conversion

[niall]

was it really 14-15 at WOT on the first turbo?

[mecmw]

Yeah, that doesn't sound cool...

[BMWTurbo]

Niall I have the WB02 sensor near the rear of the exhaust, so it could have been the slight delay in the mixtures changes getting to the sensor, It's also hard to watch the AFR meter and drive at once...

Seems the tune wasn't too bad I had in it... I had to fatten a few areas and will have to spend a bit more time on the sequential turbo transition.

See attached log of a run through 1st into 2nd and showing RPM, TPS, AFR's, Inj duty and MAP signal... You can see the RPM dip and the lean out on gear change, the factory ECU does this to save the bands in the GB, I can't tune it out. Sorry about the y scale, the 1600 line is 12 AFR. Also the big Jump in injector duty is ECU imposed for when the second turbo comes on usually around 3800 rpm.

AFR's look okay after a quick bit of tweaking, but will spend some more time on it and I also need to regap the plugs...

As a reference last time I ran it up on the dyno, with an average tune it was over 300hp atw's but It wasn't a calibrated dyno, nor did I really care what the actual figure was, I was looking for gain...

071008 1st 2nd.JPG

[niall]

i reckon that looks pretty dam good, as soon as TP is going up the fueling is going down, i would be working on at least 1-2 seconds delay between combustion and change at the gauge,


im sure you know exhaust leaks will throw your readings out the window too so make sure it is completely sealed.

yeah that lean out while shifting is just for torque reduction so i wouldnt be worried about that.

what will you gap the plugs to Ben?

[BMWTurbo]

There is roughly 1 second delay between TPS input and the related AFR output at the back end of the exhaust, I did some testing last night to work out the reaction, based on that it's not too bad really..

One thing I have found is that I'm seeing 97% injector duty at high rpm/loads so I'll probably look at bumping the malpassi base up another 5psi and see how that goes. I should note I haven't had the injectors cleaned, so they could be slightly down.

I'll be gapping back to around 0.6mm the factory coils are good for over 1500RWHP so I'm not concered with them, the weakest link in the system is the ignitor, but STD ignitors are good for over 600hp so I won't run in to any issue there either.

I had the plugs gapped down to 0.5mm in my 1JZGTE with a single turbo running 23psi. 1/2J's have a habit of blowing the spark on larger gaps at higher boosts, so it's common to gap them down.

There 'could' be a leak in the exhaust, I've been fortunate/planned well in that I only really stuck the gasket to one face so I can remove and refit without detroying a gasket each time... It would probably pay to replace these as you mention for assurance... Now that I've done the diff and TS etc it shouldn't need to come off every second weekend...

[niall]

yeah most injectors i have had cleaned are considered "good" if they are around 90%, so you could probably grab another 10% flow there

[BMWTurbo]

It's the stuffing around removing them that I hate doing Naill... I've had other side feeds flo'd and cleaned and have got bugger all gain's from it, so am a little hesitant about spending over an hour and $120 to have them cleaned, flo'd and new rings put on, then having to put them back etc...

Just changed the rear pads, pad sensor and gapped the plugs down to 0.65mm, they were originally 0.8mm and 0.65mm seemed like a better starting point, hopefully I won't have any issues.

I did notice a clear timing band on the plugs, I'll try and throw up some images tomorrow, I've never seen a band so distinguished...

[mushroom]

I hear and see it go past the PA hospital a couple of times looks good (i am the guy with the black hiking bag on my back)

[BMWTurbo]

Mushroom, Cheers... I'm often a little impatient around that area too :P

Here are a couple of images of one of the better plugs, I've never seen such a distinctive line on a plug before.
IMGP7521.JPG

IMGP7522.JPG

[niall]

yeah i have never seen such a definate line before,

have you thought about filing the plugs ben? on turbo'd cars i always file the earth electrode ton to a 1mm point over the positive electrode. it promotes a much better flame travel

[BMWTurbo]

I hadn't thought about doing that Niall. It makes sense when you mention it, I might have a think about it and see how energetic I feel about pulling them to file them down...

By regapping them I've actually reduced the chances of it arcing anywhere then either of the two corners near the electrode, but it would make sens to reduce this even further by knocking the edges off the neg electrode.

[niall]

yeah give it a go next time u pull them out to read em

it stops the spark from arking out on the side and doesnt get in the way of the flame kernel when it starts either

[BMWTurbo]

Scans to follow tomorrow, but was suffering from heat soak last night...

Best was 13.7@104
Highest MPH was 105MPH
60 foots were nothing better then 2.14seconds due to the 3.15 gearing and the fact that I couldn't get enough stall off the line with the sticky track to do much better.

I was also only just getting into thrid at the end of the 1/4. One run I let it rev limit accross the line and didn't come out with a much slower terminal.

[niall]

were you breaking traction at all in first ben or is the stall just not high enough for that rear end ratio?

edit- how much boost is it making when its loaded at max stall speed?

[BMWTurbo]

Too tall a ratio for the sequential system Niall..

I think that if I was to convert it to parrallel and not seqeutnail it would launch better...

I wasn't breaking traction off the line, was stalling to about 2400rpm and 14psi almost on the first turbo, this was the most I could stall too and it still wouldn't break traction...

I was doing roughly 100kph in first, then 165ish in second, so it's a VERY tall ratio...

I reckon I could get 0.5sec back with the correct ratio for the engine. Using 1750 race weight and the 105mpg terminal shows around 350rwhp, which is about where it should be on 18psi...