quattrobros twincharged audi 90

[audifreakjim]

Looking good! That odd area in your fuel map is due to oscillations in fuel lines caused by the injectors pulsing. Sometimes they can be eliminated by using softer rubber lines instead of hard lines.

[quattrobros]

More bad video!

[quattrobros]

Interesting. why only at that rpm? So as ethanol% is higher more fuel is needed and the pulses get larger causing that zone to be more pronounced? Maybe because my lines are still stock size too?

Ive also read that the lambda target table plays a role in those numbers as well. so a "100" VE at a target of 1.0 is not equivalent to "100" VE at a target of say 0.80. Meaning 130 in that zone is not as much fuel as i think it is compared to 115 at my WOT zones.

Could be wrong. Overall I'm not too worried about it anymore. Ive been told its not uncommon for VE to change as Ethanol % increases.

[audifreakjim]

VE of your engine doesn't change on ethanol, required fuel does. Just have to think about it a different way. For the fuel map, it is pretty normal to have a spot like that in most setups. Your injectors are not able to deliver as much fuel in that spot because of the reversions in the system. So you have to add VE to trick them into opening longer.

[quattrobros]

[quattrobros]

[quattrobros]

[quattrobros]

[quattrobros]

[quattrobros]

Currently at 25 psi. Stiffer wastegate spring on the way looking to do about 30psi soon hopefully

The jump from 20psi to 25 psi was insane. At least 50hp on the butt dyno.

My redline is at 7200 rpm. What do you guys think i can safely redline to? Head only has upgraded valve springs and a billet cam gear.

[Lucky]

The sounds coming from that thing are insane! I love it!!

[jolio1994]

This thing has all the right sauce!

[PRY4SNO]

Seeing the 90q beside a modern car reminds me how much I love the proportions.

Great work so far!

Common wisdom states 8k as the upper limit, anything else is begging for a lifter or oil pump failure. Not sure of/if any impacts of the supercharging as I believe the oil pump issue is due to destructive harmonics.

[quattrobros]

Thanks yall!

That's what I've been hearing as well 8k. Ive never heard of the oil pump failure before.

The supercharger pulley is actually attached on the outside of the crank pulley so there is that rubber between the inside and outside portion still which worries me a bit. Everything feels smooth and at 8k the supercharger isn't being driven anyway. I did get the rotating assembly balanced when doing the build and i made sure it was done the right way too as prescribed by Jeff at FRP.

No strange vibrations so far but i guess that's not something you can really feel. Maybe high 7000s?

[PRY4SNO]

Ask Jeff and let us know what he recommends!

[quattrobros]

Been a while since an update. A few months ago i was cruising along the highway when the oil pressure light came on. Had to coast it to safety which took about 2 min at 1500 rpm. Turns out there was no oil in the engine.

Went back with a different car and saw that all the oil had leaked out within 3 car lengths on the highway.

There was no knocking or funny business before shutting the car off.

Pulled the engine recently suspecting the rear main seal and it turns out the oil galley plug fell out.

What is everyone's opinion on any possible engine damage? It has coated bearings and still spins freely.

[audifreakjim]

I bought an old 80 quattro at the junkyard that they had for sale in the front for some reason. Sign said has rod knock. I took it for a spin around the parking lot, checked the oil, nothing. Bone dry. Put in my spare 2 quarts of oil from my trunk and it ran like a sewing machine for years. I went back and made them a low ball offer of $600 at the time and drove it home. I miss that car.

So I bet your engine is fine. I'd fill it oil and monitor for shavings.

[quattrobros]

just what I wanted to hear!

[[sTeeWie]]

The soundscape is great. I like it very much

[quattrobros]

Update:

Car is back together along with a new 01e. The 3-4 collar froze up on the other one. Probably going to rebuild one and make a homemade cable shift setup.

Runs as smooth as before no knocking or weird noises. Feel super lucky!

[MikeB25]

Probably going to rebuild one and make a homemade cable shift setup.

My son and I have had a cable shifter on the drawing board for several months but the CQ project is nowhere ready for it. We might be interested in sharing in the development and defraying costs, and we're just up the road.

[mrdeye]

Update:

Car is back together along with a new 01e. The 3-4 collar froze up on the other one. Probably going to rebuild one and make a homemade cable shift setup.

Runs as smooth as before no knocking or weird noises. Feel super lucky!

Awesome!!

[quattrobros]

Things are about to get exciting for the 90 in the next couple months!

The replacement 01e i threw in last year ended up having an unfixable input shaft leak. This was causing oil to get on the clutch and ruining everything. Ended up pulling the engine 3X in one month and replacing 3 clutches thinking i had fixed it everytime. I ended up giving up and took a break from it for about a year. In the meantime i was searching for an FYF transmission.

Since then ive found a GBE trans with 100k on it that is getting a JHM rebuild kit and an EDU 6th gear swap.

I have also been working on that self centering cable shifter. Some of the parts are still 3D printed but im working on a way to get access to a lathe / mill.

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Keep in mind linkage isn't connected or anything.

Ill have tons more pictures of everything once things pick up in the next few weeks.

[MikeB25]

My neighbor has a machine shop and does all of my stuff so we might be able to help you out. I could even deliver the parts!

[quattrobros]

A look inside the GBE trans. Cant believe how clean this thing was. Also i think it has a flexible main shaft? I've read this is a good thing? If so, thats an extra bonus to this swap!

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