Hacker-Pschorr

In case you did not know the S4 / GT / GTS heads have built in ports for EGT (exhaust, gas, temperature) sensors. Not until 1990 were these used by Porsche. The 1990+ cars have two EGT sensors (one on each cylinder bank).

Few years ago, Todd installed eight EGT sensors on his 928 to monitor each cylinder. Todd is using Autronic on his car, which allows him to tune each cylinder individually for not only fuel but also timing.

To make a long story short, Todd was never happy with the performance of the EGT sensors (too slow to react) and recently switched to eight O2 sensors. Most people would think you can simply weld an O2 bung into the exhaust manifold for each cylinder. This has two issues:

1. Todd did not want this restriction in each tube
2. Even if the above were not an issue, it's way too hot. The O2 sensor would not last very long (he tried that already)

So here is what Todd came up with. The install took about 45 hours per his notes, he thinks the setup could be duplicated in 20-25 hours the next time around.

The speed at which these 8 sensors react is nothing short of amazing. On the dyno it was easy to see the speed difference between the eight O2 sensors Todd installed over the single unit.
They also installed a tailpipe O2 sensor, that one seamed to lag behind the eight by about a week.



This is the adaptor Todd created to isolate the O2 sensor fromt the exhaust manifold heat. The engine exhaust flows through this adaptor accross the O2 sensor head:




As you can see here, the output from the O2 adaptor runs to the X-pipe:








Here is one O2 sensor in its adaptor wrapped in a heat protective material:








Off Topic - here is the air / oil seperator Todd came up with for his car. I'm probably going to duplicate this setup for my track car:





Previous Todd thread:
https://rennlist.com/forums/928-forum/312176-todd-s-website-is-finally-up-more-pictures-of-the-427-powered-928-a.html

Dyno of this car:
https://rennlist.com/forums/928-forum/395749-latest-dyno-from-the-green-bay-crew-todd-s-car.html

Jean-Louis

Just Todd can do that, incredible work, very well done as usual.
Bravo

FlyingDog

Damn, that's impressive. Your imaginary friend has way to much time on his hands.

Jean-Louis

All the serious racer should do exactly this setup and will gain power..............

Big Dave

Next time use a larger font.

Rob Edwards

Looks like he's installed a cooling rig for a really overclocked processor. Cool!

Are all those LC-1's going to be OK down in the dirt like that?

Hacker-Pschorr

I knew I would get crap for that. With the pictures it was hard to see the type, so I bumped it up

Mike Simard

That's impressive work. As far as modifying cars the rest of us are just sniveling softies compared to him

What's the oil filter thingy?

Hacker-Pschorr

Heatsink / magnet

AO

[2nd grade voice]I could do that too... I just don't want to. [2nd grade voice]

Very cool! He told me about this, but I had a hard time imagining it. Thanks.

Tom. M

Just a quick correction...Porsche started using the EGT sensors in 89. They originally used the 4 and 8 position, however in 1990 switched to the 3 and 7 due to better response from the sensors.

Aside from that..very very cool what he is doing.
Later,
Tom
89GT


In case you did not know the S4 / GT / GTS heads have built in ports for EGT (exhaust, gas, temperature) sensors. Not until 1990 were these used by Porsche. The 1990+ cars have two EGT sensors (one on each cylinder bank).

Imo000

Very nice!
I’m guessing that he plastic zip ties are just a temporary solution. Why is the BPV/BOV sitting so low in the engine bay?

JEC_31

Holy crap that's a lot of plumbing.

I say shield it from rocks! Need a full belly pan by that point.

Love the uber-detail engine management approach.

How much variation between cylinders is this massive array of sensing equipment seeing?

PorKen

Where's the A/C? 700HP, and fogged up windows? Scary!

IIRC, these were used for air injection in some markets.

Nice shot of the 'Gear Bender'.

Rick Carter

To meet Todd, he's the nicest guy in the world. Tell him I said hello and ask if he can make an air/oil seperator for my 85. Ken and I were also talking about coming up for a shark tune on our 85 SC cars.