Marc's 1990 4.2L V8 Twin Turbo Coupe Quattro

[Marc]

Marc, you actually work on your own car? I see you tuning and wrenching on other's cars, but wasn't sure the coupe got any attention. I guess it does!! Looks good.

ha. not often these days. actually I had Jim (glibobbo21) work on the gas tank for me since he works part time for me, as well as Josh (AllOutOfDonuts).

[Karl Buchka]

Marc,

It was great to meet you at the shop the other day. This is a very cool build you've got going on here.

Few things that jumped out at me while reading through your thread:

x You've got the EGT probe in the downpipe. The pressure drop across the turbine will skew the readings enough to make them largely useless. A single EGT probe in the collector is also largely useless, but that's another discussion. :-)
x 2.5" single exhaust. :(
x Stacked gaskets. :( You may have dropped the SCR a bit, but at the same time you've eliminated any squish you may have had, likely making the engine more prone to detonation than in stock form.
x Any pics of the ports before/after porting? How much material did you remove, and where?
x Interior/wiring pics?

[loxxrider]

Karl Buchka wrote:[/quote]Marc,

It was great to meet you at the shop the other day. This is a very cool build you've got going on here.

Few things that jumped out at me while reading through your thread:

x You've got the EGT probe in the downpipe. The pressure drop across the turbine will skew the readings enough to make them largely useless. A single EGT probe in the collector is also largely useless, but that's another discussion. :-)
x 2.5" single exhaust. :(
x Stacked gaskets. :( You may have dropped the SCR a bit, but at the same time you've eliminated any squish you may have had, likely making the engine more prone to detonation than in stock form.
x Any pics of the ports before/after porting? How much material did you remove, and where?
x Interior/wiring pics?[/quote]


EGT in the downpipe isn't useless at all.

Doesn't matter what the number actually is for things like tuning timing. Just matters that you hit a low valley point. Thats when things are good to go. Temps get higher means you have too little or too much timing. The lower it gets, the more on point you are.

[Marc]

EGT in a runner would be better, no argument. The next manifold I build for the car will include sensors in the ports. The EGT data is still relevant in the downpipe location though.

I disagree on the detonation resistance. stacked gaskets are not ideal, and yes quench area is lost, but to me the proof is in the pudding. I've dyno tuned the car at 26psi on pump gas with no det. Do that with 10.5:1 CR, I dare you

I have porting pics, I'll dig through my gallery and find them, same with wiring stuff.

[Castor Troy]

marc, iirc the abz has a dual plenum intake manifold(adjustable between single plain and dual plain depending on RPM). did you do anything with your ECU setup to control that?

[Marc]

Castor Troy wrote:[/quote]marc, iirc the abz has a dual plenum intake manifold(adjustable between single plain and dual plain depending on RPM). did you do anything with your ECU setup to control that?[/quote]


its not an ABZ intake (nor an ABZ engine for that matter, its the older ABH 4.2). the valve covers are the only thing ABZ on my car at the moment.

A custom intake manifold is in the plans eventually for the car.

[Marc]

some updates on the fuel system upgrade today. I started mocking up the fuel pump tray with the pumps and filters. final version will include rubber insulated band clamps (IE not zip ties). I'm short one fitting, and I'm going to re-do the bend near the driveshaft to get a bit more clearance. all in all pretty pleased with the layout.

[oldsklaudidub]

Nice. whats your gph going to be?

[Marc]

Nice. whats your gph going to be?

600 liters/hour or about 158 gph (@5 bar) is the capacity of dual 044s.

[jay54f100]

Im sorry but I think something just happend in my pants that I shouldnt share with evey one. WOW that is awesome job. Keep up the good work.

[loxxrider]

Nice Marc! I gotta talk to you about the 044s sometime.

[my2000apb]

so are you running single line forward?

[audifreakjim]

Whoa. Having just spent some time with this most undesirable part of my car, I really appreciate that setup. Nice work. Are you going to clamp them down with something more permanent?

EDIT: I just read this:

final version will include rubber insulated band clamps (IE not zip ties).

Sorry, I was distracted by the pictures

[HT Motorsport]

Sweet! that is definately going to flow enough to turn up the boost

[glibobbo21]

i never saw it in the car..looks tits..especially with all the fittings

[85oceanic]

WOW! Looks great! .... .... I want!

[audidub]

looks like everything fits the way its supposed to for the most part, I'm really glad everything lined up on the panel with the fittings. Keep up the good work :cheers:

[Hank]

very nice. Looks spensive!

[Dan McBoost]

Those specs are serious. Oof. Sfesting that this year?

[Marc]

yep, I'll be at //s fest.

fuel system is just about done. just need to run the power wires for the pumps into the car. system is now leak checked and base pressure has been set

shot of the tray with clamps and rubber isolating the components:



(blurry) shot of the sump that sticks through the underside of the car, I used 1/2" NPT female bungs, two for outlets, one for return. the return line has a pipe inside the tank that directs the return flow away from the inlets to avoid turbulence.



engine bay side of the plumbing.





that oughta flow some fuel, I think

[death 4kqt]

got dyno time planned yet?

[Hank]

wowsers

[85oceanic]

Dang... what I woudn't give for a ride in this beast! Looks freakin great Marc!

[loxxrider]

whatever you would give, its totally worth it

[Marc]

aaaand its back up and running! I had to fabricate a new clamp for my intake pipe as the old one interfered with the new fuel lines/rails. after finishing that (and christening my new mini-mill lathe in the process) I took the car for a rip up the road. Man I missed this car.