hacker-pschorr

I didn't want to hi-jack Carl's thread on his spacers, so here is a new thread.

When Todd first started tuning Autronic on his car, he was using a combination of EGT and old fashioned spark plug reading. Unfortunately the EGT method was not very reliable (why he switched to eight O2 sensors).
Via spark plug reading, he was consistently seeing cylinder #5 was rich compared to the other cylinders. After adding the left side spacer, he was able to add some fuel back into #5, but still not as much as the other cylinders.

Since adding the eight O2 sensors, he has not gone back to play with spacers, different thicknesses, adding one to the right side etc….. He might down the road, as of right now it’s not on the immediate agenda.

Here are some images I took of his spare intake showing why #5 has the worst breathing:

IcemanG17

Great photos......it does seem like #5 is by far the worst, with probably 8 being next?

Tony

Whats the coating he used on the inside?

Jim R.

I think a set of spacers is going on before spring.

Jim

PorKen

Big {plenums}, big {plenums}

Talk about {air flows}, my girl's got 'em

Big {plenums} drive me out of my mind

How could I leave this behind?

toofast928

Good stuff Erik, pics make logical sense.
Tony

Vilhuer

Is S3 intake answer to all the problems?

dprantl

Yuck, that is absolutely awful! How could Porsche engineers allow that bell mouth to be practically touching the cover at one point?? The more I look at the late intake the more I don't like it. What you would need is a box attached to the end that follows the shape of those pipes so the distance to the cover from any pipe is the same.

Or... just slap on an early 32v intake

Dan
'91 928GT S/C 475hp/460lb.ft

RyanPerrella

has anyone for ****s and giggles ever run an 85-86 intake on an S4?

dprantl

Well, for an otherwise unmodified S4 the results would probably be power figures of an early 32v. Although head volume is different, compression ratio is pretty much the same and displacement is as well. LH 2.3 main difference is addition of flappy solenoid actuation inside the intake. EZK just added knock sensors over the EZF, so no power adders there either. I would be interested to see if a change to the S3 intake would help in a stroker and a supercharged car.

Dan
'91 928GT S/C 475hp/460lb.ft

Larry928GTS

Keep in mind that the side plates aren't simply flat on the surfaces that mate up against the intake manifold. The back sides of the plates are not as close to the bellmouths as they would be if just flat plates were bolted on the sides. I'm not saying that the plates aren't too close to the bellmouths, just that it's not as bad as it might seem from just looking at the pictures with the sides off the intake.

Also, remember that these intakes have still managed to flow a lot more air through them than Porsche designed them to. Just because it might not flow as much as a 500rwhp engine might like, it might be plenty for a 300rwhp one. If the stock configuration flows enough for a relatively stock engine, you're not going to gain a thing even if you move those plates out a foot from the bellmouths.

I'm not really familiar with the '85-'86 32v intake manifold. Does it feed the same cylinders from each of it's plenums as the corresponding cylinders and plenums of an '87+ intake?

PorKen

Come for the cams, stay for the intake!

S3 intakes aren't a bolt-on unfortunately. The intake ports are oval in different directions. You would need a spacer/adapter to fit them to an S4.

Each plenum is routed to the same cylinder as an S4 intake.

Putting bigger valves in a S3 head would be interesting...

ew928

So anyone have a picture of the inside of the side plate?

BC

It has large cast in ribs. I had a machinist take them out so the plate is more recessed in preparation for assembly, but I sold the intake to Aggrivation. Its a good solution for a bit more room I think. That and a spacer could work wonders maybe.

Stromius

What about CNC'ing or constructing 'bellowed' intake sides in kevlar/resin a la 911 crowd? By adding some curves to the flat sides and adding intake spacing, would that solve the constriction for #'s 5, 8, 4, 1? Might even look nice with the existing curves.