MP 90 FWD Project Updates

[TGP37]

MAF effects a lot more than fueling too... it's also paired with cylinder displacement to form the grams/mg per cylinder value used in a LOT of calculations. i would assume a calculated airmass temp is also used to correct that value, but it's effect wouldn't be as significant.

I never thought about it that way but yes.....so having a MAF curve out of tune will also throw the spark out of tune. As the table relies on grams/cyl to determine advance.

Even more reason to get the injectors tuned right before messing with the MAF table.

[AleroB888]

Got sidetracked on the exhaust

Here's how it sounds after driving over 30 miles on a warm day, hot start. Sorry about the wind noise, but I wanted the sound out in an open space. So, for the record, we have TOG headers > custom downpipe by Hanksville in CO > 3" Magnaflow CAT > 3x5x15 Borla XR1 round case > Magnaflow 14828 3" oval muffler/tip. That's about as straight-thru as it gets with a full exhaust. Louder with a cold start.

http://www.youtube.com/watch?v=GzjD3W01LoM

Vanishing point, hot lapped that puppy

http://www.youtube.com/watch?v=LCaY2...ature=youtu.be

[AleroB888]

alc inj

Vanishing point, hot lapped that puppy

http://www.youtube.com/watch?v=LCaY2...ature=youtu.be

More hilarity, in the heat of the summer the Saab plastic coupler (SC outlet) "melted" after taking that vid, almost got stranded. heh

So now working on a new coupler/casting

and hooked this up, but under-engineered at least one component.... there's a 35psi pump and pressure switch under the MAF sensor somewhere...

the pressure switch failed, stuck "ON" after a WOT pass on the highway, which dumped in 50/50 alc/H2O at a rate of 8 ounces/minute.

But did we panic? Oh, no, this type of stuff is expected


(simul-posted on A-Mod)

[3400-95-Modified]

the pressure switch failed, stuck "ON" after a WOT pass on the highway, which dumped in 50/50 alc/H2O at a rate of 8 ounces/minute.

But did we panic? Oh, no, this type of stuff is expected

I always hear about people having issues with Meth systems... I would think you would only have as many issues as I would with my Nitrous so what gives? Is it just cheap switches used to enable the system going bad?

I've had more issues with my nitrous not coming on than ever getting stuck... I use only a WOT switch so yeah that's a bit different but this is why I'm switching to fully electronic controls off the TPS readout and also progressive engagement since the straight on is not working.

[AleroB888]

I always hear about people having issues with Meth systems... I would think you would only have as many issues as I would with my Nitrous so what gives? Is it just cheap switches used to enable the system going bad?

I've had more issues with my nitrous not coming on than ever getting stuck... I use only a WOT switch so yeah that's a bit different but this is why I'm switching to fully electronic controls off the TPS readout and also progressive engagement since the straight on is not working.

It was poor judgement on my part, actually. Prior to this I had used the same type of adjustable pressure switch on an intercooler pump and an alcohol injector system for years with no problem. It's not a heavy duty switch, but not bad. I could not find a definite current rating from the manufacturer, but I estimated 5A @12V. I had a 7.5A fuse in line with the system.

But this time I added a fuel solenoid to the system, wired in parallel with the pump. The DC resistance of the pump is approx. 6 ohms, and also 6 ohms for the solenoid, so the system current draw increased. It did cross my mind to install a relay, but I was wanting to keep the wiring simple.

Now I had done a few days of testing with 2 different nozzles, and was getting what looked like promising results as far as Knock Retard. Then the switch failed. I have to say that the solenoid appears to be very durable, since it got burning hot but never failed.

I'll use a manual switch for testing in the near future, and work on a relay system next.

[Guest]

Always use a relay with a switch of unknown ratings, ALWAYS.

The other benefit is that the path is shorter between the battery to the load device that increases its ability to perform reliably.

[AleroB888]

Port the inlet, or not?

Here's a pic of how much is left on the table as far as porting and smoothing the inlet.
You can see the casting flaw on one side, and the black edge of the gasket, on the left shows how much overlap there is:



Now the unit is already producing far more boost than I expected, so I don't want to make the mistake of removing too much material. (other than smoothing and matching the surfaces). There's enough metal inside the casting to flatten it, or leave it horn-shaped as it is now. Any recommendations?

The SC inlet surface area near the rotors is about equal to a 4-inch circle, the throttle body 68 mm. The flat surface of the SCs inlet slants inward at about a 45* angle (see below). I theorize that angle helps flow "turn the corner" from the throttle body.

The stain on the gasket is seepage fom the PCV system.

[hookdonspeed]

hrmmmmm, i love this setup, wonder if i could squeeze something like that into the 3500 fiero...

[carbon]

hrmmmmm, i love this setup, wonder if i could squeeze something like that into the 3500 fiero...

Looking at that pic... the Fiero strut towers are in a somewhat similar location relative to the engine... the supercharger drive shaft shouldn't be an issue on the drivers side, but the location of the supercharger itself would definitely interfere with the decklid hinges, if not with the decklid itself... There's Blooze's hinge replacement and maybe if you used Darth's trick to lower the engine way down in the bay.

Who knows...

[AleroB888]

[young gun]

Nice port work.

What is with the 3 clamps on the rubber coupling before the 90* into the intake plenum ?

[AleroB888]

Nice port work.

What is with the 3 clamps on the rubber coupling before the 90* into the intake plenum ?

I have an insert (black ring in pic) added to the 90 degree aluminum elbow, and the clamp keeps the silicone coupler from ballooning out, gives smoother flow.

[unchained01]

Didn't that tube actually "blow" off at one time when you first installed the S/C ??

[AleroB888]

Didn't that tube actually "blow" off at one time when you first installed the S/C ??

I had a 90 degree silicone coupler that needed support else it would collapse under vacuum. And a plastic tube that deformed and leaked in the Summer heat. And clamps that moved around when the PCV vapors oiled up the connections. Just the usual stuff, but it's getting better.....

Got one new mount done, 3/16 steel bracket with a 1/8 steel brace. Now much easier to install or remove SC. Took it for a test today, first time it's been run in 6 months. Forgot to look at the boost gauge, though Also re-oriented the bypass valve so no modification of the fan shroud is needed.

[fasteddi]

looking nice man!