Budget 4.4+ jaguar supercharger build

[geargrinder]

The problem is that the intake air temps on a MAF car are used to simply adjust the values provided by the MAF. For that reason, it makes most sense to keep your IAT sensor in a location where it experiences the same temps as the MAF. If it's a draw-through configuration, you can just stick your IAT sensor through the tube right in front of the MAF unless you have CCV sloshing oil back into your intake tube in front of it or something.

Yeah. Dont forget, in additon to mass-calcs, its also often used in timing adjustment Thaddo... usually pre-emptively reducing timing a bit.

That's a homebrew hackers (and many pros) favorite trick. Stick the IAT in some ice cold location way up in the front bumper. Bottom line is it tricks the ECU into keeping timing where it would normally pull it. It's a sorta-way to add timing without (bothering to / learning how to) actually adding timing to the tune.

To be fair, sensor heat-soak IS a real thing and IS a fair enough reason to re-lo the IAT somewhat, but in my highly scientific GG statistical research studies (using our patented rectoextraction calculation techniques) most of what guys are getting excited about is the fake-o effect, and because you've thrust it into some place way out of the actual intake plenum temperatures... and not because of it fixing the 20-30%-whatever% of the time its true heatsoak.

Ideally the IAT is actually IN the manifold, but is invincible to heatsoak, and you then tune aggressively to those temps, knowing they are reliable. But since heatsoak invincible sensors seem to be not practically realistic... and because IAT re-lo feels good to the buttyno... we have the frenzy for IAT re-lo...

[tptrsn]

Yeah. Dont forget, in additon to mass-calcs, its also often used in timing adjustment Thaddo... usually pre-emptively reducing timing a bit.

Yeah, I can see that at least should be part of the strategy. For the M5.2 I never really found anything done with the IAT other than offsetting the output of the MAF, so that led me to conclude I should just place it in a location where it would be registering a temp very similar to what the MAF would be seeing.

Which actually does bring up an interesting point related to the timing issue. Timing values are derived from load and RPM, and load is derived from airmass and RPM... Anyway, if the IAT isn't giving the DME a signal that correctly offsets the MAF signal according to temp, then it's timing that would be effected in addition to the pulsewidth, but not necessarily in the direct "hotter IATs deserve reduced ignition advance" sort of a way.

It's too late in the day for my brain to be capable of pondering just which direction these considerations would lean, especially without opening up WinOLS and finding that MAF temp offset table. Ugh! This really made my brain hurt.

[1999 540i m]

I finally get to drive my car, I've put about 1000 miles on it so far, and then I get a 90 mile ride on a flatbed,

I was passing a truck, screaming down the road, then p1357 pops up, dead #8 cylinder, about 10 seconds later complete ignition failure.


IMG_1033.jpg

I had a set of coils in my shopping cart the day before and decided not to buy them, today I ordered a set of bosch coils,
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[philly98540]

Never saw a coil melt like that! Nasty nasty. Glad to hear it was running good! Up to that point....

[JimLev]

Looks like an alien space creature.

[tptrsn]

Wow!!!

It will be interesting to see if a fault in the DME caused that by over-dwelling that coil, or if that coil going bad somehow caused the shut down of the ignitions system...

[1999 540i m]

Wow!!!

It will be interesting to see if a fault in the DME caused that by over-dwelling that coil, or if that coil going bad somehow caused the shut down of the ignitions system...

I don't know about the first part, But the ignition shut down from a blown 30 amp fuse in dme box, I swapped coil packs replaced the fuse, and it fired right up, I drove it into the garage, waiting on my new coils before I drive it again

[JimLev]

Might want to pull the cover off the DME and look at the coil drivers.

DME7.2c.JPG

[tptrsn]

I don't know about the first part, But the ignition shut down from a blown 30 amp fuse in dme box, I swapped coil packs replaced the fuse, and it fired right up, I drove it into the garage, waiting on my new coils before I drive it again

That sounds good!!

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Cool pic and labels there Jim! Did you sort all of that out?

[1999 540i m]

Might want to pull the cover off the DME and look at the coil drivers.

DME7.2c.JPG

Good idea, I'll inspect for signs of heat damage, I've been meaning to get a spare parts dme, for those coil transistors

[JimLev]

That sounds good!!

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Cool pic and labels there Jim! Did you sort all of that out?

Thad, yes I did it when I rewired bank 2.
None of those wires go over the top of the intake manifold.
With all the plumbing on top of the intake manifold there wasn't room for all those wires.

[tptrsn]

I would love to see a shot of the top of your engine now Jim. Do you have some in a thread or something?

[JimLev]

There's a thread of it, not sure if the pics are still posted as Comcast decided to dump free hosting a few years ago.
Sorry to hijack your thread 540i M.


The start of the rewiring to bank 2 and relocating the wires that run down the front of the engine from bank 1.

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After painting the intake Ti Silver, too much black under the hood. Silver never looks dirty.
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[tptrsn]

Thanks Jim, that looks amazing!

I think I would like to get rid of the wiring boxes at some point. They are kind of a pain... (as much as I change injectors and whatnot)

[philly98540]

I know right? Hate those boxes!
That silver intake is really sharp Jim

[tptrsn]

I know right? Hate those boxes!

THANK YOU!! Yes, those boxes are a huge irritant for me. Thanks for confirming that I'm not the only one bothered by them!

[JimLev]

I'd also love to dump the wiring boxes too. Thought about it a lot when I was rewiring the engine.
Just need injector and coil wires. The wiring at the front of the engine could go under the manifold.

[1999 540i m]

Got my new coils today, made a major difference in idle smoothness! and much smoother at 2500 rpm, even seems to rev quicker

I checked the DME for heat damage, all looks good

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The spark plug looks good to me, What do you experts think?

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[tptrsn]

I personally don't see anything obviously wrong with that plug, but a lot of what you'd be looking for will only be seen with careful focus, lighting, and magnification:

vlcsnap-2017-11-25-19h24m13s717.jpg
For example, and even this one doesn't properly show down in the plug along the side of the porcelain.

[1999 540i m]

I personally don't see anything obviously wrong with that plug, but a lot of what you'd be looking for will only be seen with careful focus, lighting, and magnification:

vlcsnap-2017-11-25-19h24m13s717.jpg
For example, and even this one doesn't properly show down in the plug along the side of the porcelain.

Thanks, I'm learning as I go, reading plugs is not something I know a lot about.


I put some around town miles on my car today all seems good, I'll be replacing my intake tubing soon, it needs more space!

[516SC]

616611[/ATTACH]

That gap looks too big, I use 0,5-0,6mm

[1999 540i m]

That gap looks too big, I use 0,5-0,6mm

The picture is deceptive, the plugs were correctly gapped 1000 miles ago, I did not recheck the gap, but I don't think it would get bigger, I don't know

[tptrsn]

He's saying the gap looks big in general I think. As in it might have been set to normal specs for an N/A use? Around .035"-.040" maybe?

.5mm-.6mm is in that .020"-.025" range that I like to use for turbo setups, but the one I posted in the picture above was actually set at about .015" (.38mm).

[1999 540i m]

He's saying the gap looks big in general I think. As in it might have been set to normal specs for an N/A use? Around .035"-.040" maybe?

.5mm-.6mm is in that .020"-.025" range that I like to use for turbo setups, but the one I posted in the picture above was actually set at about .015" (.38mm).

I never adjusted the gap only verified They were all the same I don't remember, What is the correct gap for the ngk iridium plugs for my supercharger setup?

Just looked up current plug gap ngk spec 0.031

[philly98540]

I use 0.026" on my iridiums.