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Remapped car again. Had a slight plug problem.


Jake

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Me and Ryan were out mapping my car today to make sure it was set up properly for the GT40.

After some initial messing about getting the right Motec software versions so the laptop so the ECU could talk to each other we eventually got started about an hour late. Then it was out on the road mapping for a good few hours.

 

He's got balls of steel that Ryan. I'm buggered if I'd sit there with det cans on and stare at a laptop while some fat bastard thrashed his Supra along dual carriageways at 140-150 leptons.

 

We got it mapped great at 1.0, 1.25, and 1.40 bar and were about to call it a day when the engine developed an on-boost misfire :(

I tried turning the boost back down to 1.0 bar but it still misfired when in positive boost. So I took it easy on the way home and swapped the BCPR7ES plugs for some GReddy #8 iridiums. This seems to have cured the misfire but I'm left wondering what happened to the old copper plugs. They looked fine when I took them out, although they were gapped a little big maybe (about 0.9mm).

I'll probably try a new set of coppers in there next week and see what happens.

 

Is it common for plugs to fail under boost/hard use but run fine again when off boost?

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Could just be a case of spark getting snuffed out with the boost pressure getting higher, try gapping them to .7.
I could understand it being that if it wasn't for the fact that after it started misfiring (at 1.4 bar) it then misfired at a lower boost levels - levels that it had been fine at earlier in the day.
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I found the same Jake. My plugs (same as yours) were gapped to 0.8mm, but developed a misfire on high boost (1.4bar). Problem is, this continued even after dropping the boost. Put a new set in and gapped to 0.7mm and its fine.

 

I think that once the NGK's start playing up they're goosed for good.

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I WANT JAKES CAR!!! :D Made mine feel slow :(

 

Roll on rolling road day as i exspect great things from this car

 

Ryan

 

What's different on Jake's car Ryan to yours? You're both running the same turbo aren't you? I suppose you do have the advantage of a set of good forged pistons Jake - nice!

 

How does she compare to running on he old turbo now?

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What's different on Jake's car Ryan to yours? You're both running the same turbo aren't you? I suppose you do have the advantage of a set of good forged pistons Jake - nice!

 

Jakes car is running Forged pistons so probably running a higher compression ratio, Its also got hks exhaust cam fitted not sure about intake. Yes is also vvti and makes a good difference in torque.

 

His turbo also has a bigger exhaust housing and he is running more boost than me. I can not run 1.4 bar at mo as clutch is slippy at 1.2BAR+

Still have standard clutch and no time at mo to change due to mapping nearly every night.

 

But i wanted to see what power the standard clutch could take and its held up 503bhp at 1.1-1.2bar for a good time but does not like 1.3+ :(

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I know Jake's is a vvti but I don't really see that as a big power adder and not the spool lifesaver people profess it to be either.

 

If you compare Terry's and Wez's dyno Wez has more low end torque and that's even with his non dbb turbo, cast mani, 3"DP, non vvti, stock cams.

 

I suspect the forged pistons are a plus for sure. Given Jake's is running more boost, larger turbine housing and a non stock exhaust cam I'd expect hime to make more power. I got the wrong impression from the cooments (I thought your specs were the same but some how Jake's was making more power).

 

Anyway - best of luck with it Jake, it sounds like you shafted a plug at high boost. LEt us know if/when you get some RR numbers! :)

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What's different on Jake's car Ryan to yours? You're both running the same turbo aren't you?
We both have a GT4088 but Ryan's has the 0.81A/R, mine is the .96

Other differences, mine has 264 cams and pretty good intercooling according to the Motec logs (GReddy 3 row)

 

How does she compare to running on he old turbo now?
The boost doesn't really start to raise rapidly until 4krpm. When it does get going it's a fair bit quicker than the old PHR1 and it doesn't run of of puff before the redline, unlike the the PHR1 which just dies around 6000rpm.

 

With the .96AR 4088 the spool is coming in later than I thought it would and to keep it in the power band you need to keep it above 4k really. This isn't a problem on a 6sp but but I reckon it'd be no good for an auto.

 

To be honest, I'm considering swapping down to 0.81AR now. the .96 makes more than enough power for me but I'd prefer it to come on-song about 500rpm earlier really. On the other hand, because it's not on boost all the time it's very economical. I'm getting better MPG than I did from BPU and nearly double what I was getting from the PHR1.

 

 

 

I know Jake's is a vvti but I don't really see that as a big power adder and not the spool lifesaver people profess it to be either.
You may well be right. The spool now is certainly nothing to write home about. With the PHR1 it was amazing but that's no use if the turbo is spent by 6k, is it?
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pretty good intercooling according to the Motec logs (GReddy 3 row)

 

Pretty good is a understatement the air temps were fantanstic and im trying now to source just the greddy core. Have managed to find one for a skyline of mate so will try that as my intake temps are about 10-15 higher.

 

Air temp outside yesterday was 21c according to bbc and jakes intake temps were constantly around 35c at 1.4bar

 

Has to be one of my favourite cars as well thought out car in all areas.

 

MPG should be alot better now bud as afr were just too rich on dans map for cruise

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Is that good then?

From what I'd read on here I was under the impression that a decent intercooler could make the intake charge about the same temp as the ambient air.

 

No way that is possiable bud

 

no matter how good a intercooler or chargecooler is the intake temps will always be around 10c more than outside on a very good setup.

 

What u have probably seen is air temps from dyno graphs where the operator puts the intake temps to the same as outside.

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That's good to know I made the right choice of FMIC then :D

 

Expensive but worth it so it would seem :)

 

This sounds like it could be the perfect turbo match for me given I have a 4,000 stall TC. Wonder what it'd be like on std j spec cams?

 

Cheers,

 

Brian.

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The boost doesn't really start to raise rapidly until 4krpm.

 

That does seem a little late... I am hoping mine will be on full chat by 3.7... I remember Jamie P saying he was hitting the wastegate by this. my tub is also .96, but b bearing.

 

I'll find out next week one way or the other.

 

Do you have a divided manifold?

 

edit - I also bought a greddy 3 row for my first bpu, the difference it made was ehnormous. it ended up in a skip however as I a mangled a corner.

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That does seem a little late... I am hoping mine will be on full chat by 3.7... I remember Jamie P saying he was hitting the wastegate by this. my tub is also .96, but b bearing.

 

All depends on what gear were talking about though ;)

 

i exspect jakes talking about 3rd or 4th, in 6th i exspect it spools alot quicker

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I guess so.. jamie was talking about 6th :innocent:

 

It's the only gear I measure spool in for when you want to go hard you can change gear, but when I'm sat in a motorway queue I can't be arsed to keep going through the box. Having some pull at 2.5-3k in 6th makes for a lazy drive, and my biggest issue for slow spoolers.

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MPG should be alot better now bud as afr were just too rich on dans map for cruise

 

Is it not on closed loop lamda control on cruise? It's pretty good on the Motec - mine has my wideband hooked up and is on closed loop all the time, but you can use the stock narrowband too for cruise and idle.

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As it happens I've just been out (manually) logging the boost/rpm response.

I found the flattest looking DCW I could find round here and did a run in either direction.

 

6th gear (to compare with JamieP) from a 2500rpm roll

 

3000rpm = 0.30, 0.33 bar

3500rpm = 0.75, 0.85 bar

4000rpm = 1.36, 1.38 bar

 

 

Make of that what you will :shrug:

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Do you have a divided manifold?

 

Sorry Mike I missed that question earlier.

Yeah I do have a divided manifold but not a div tang turbo, so there's no advantage in it.

I wanted a divided housing but couldn't find one at the time. I would still like to try a .96 or 1.06 divided 4088 though.

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