'87 4000cs quattro Challenge Build

Why do you want your temps so low? These engines are supposed to run between 195-210. Mines tends to hover around 195, so I was quite happy about that.

Kind of strange how you couldnt get it to rev past 3k on the dizzy. when I finaly got mine to fire, it idled at 3k I had forgotten to pulg the ISV holes, so it had a HUGE vaccume leak.

Im not sure what Eric was running exactly, but you know my head is far from stock, and quite frankly, it shows when my K24 is spooling close to 500RPM faster than most other I have seen. It smokes a little if it sits for a while(which it tends to do) after that, all is well in the land of the turboladder.

As for the trigger wheel, I have a couple spare 10v dampers, I am actually thinking about machining a 60-2 wheel right into the outer most groove, as I am only running 2 belts, and that one isnt being used. My only concern is that it is very possible for the pulley to turn on the rubber. Needless to say, that would be a bad thing.

Sucks that you have to go back to the K26, thats a pretty massive step down in spool. I hope you dont go through all the trouble of doing this just to have the k26 smoke as well.

Also, what size exhaust are you running? I have a URQ downpipe to a Stebro exhaust, so basically I am running a 2.5" turbo back exhaust. From what I have seen, a lot of people tend to go too big on the exhaust, and it is pretty well pointless, at least in my opinion.

If you would like, I have a seriously updated MSQ file if you would like to check it out. Tuning has taken quite a while, but most of it has not been done by me. The more I tried, the worse it got. Pretty much everything I did would be different when I got a file back from the tuner. Let me know.

took the audi on its first real shakedown this weekend, driving the couple hours to Ouray I was able to figure out a couple things. 1: my smoke issue has been my crank case ventilation the whole time. 2: I should probly get a catch can and plumb that in soon

the car is running good. reliable. feels good when it spools up. still tuning of course. I have a very repeatable hesitation from 3-4000rpm that I haven't managed to figure out. took some logs, no sync loss or anything weird like that. gonna take a closer look at the datalog I took this morning but so far nothing is jumping out at me. anyway. here are some cruise pics

roter berg kreuzen is a little euro gathering/cruise we have in southwest Colorado each year, driving over the famous red mountain pass. it would be cool to meet a few other GRMers at our little event someday. . .

de80q: I guess I just like to keep these old counter flow heads cool. My old L-series Datsun experiences heat soak detonation on track on a hot summer day and its only 10.4-1 NA. switching to a 160 thermo helped that car enough that i was even able to get some timing advance back! I feel like anything I can do to help cool a 10vt is likely a good thing as hot as they run. when you say these are supposed to run 195-210 are you referring to the need to pass emissions on CIS? the thought of this thing at 220 makes me cringe. I even still have a hot heater so I just cant see/think of a disadvantage to the cooler running temp. just my 2 cents

as for the trigger, I'm pretty jealous you have the access to machine a 60-2 front pulley. I miss machining I was scared of the rubber separation thing also. mounted mine to the inner piece for that reason but the cleanliness of a one piece wheel would be great

the K26 is definitely a downgrade but it will give me a chance to rebuild the k24. I already miss that snappy, almost instant spool. I do feel pretty dumb being mainly a pvc problem but it was leaking a little oil anyway so better to rebuild it than burn it up I guess.

my exhaust is just catless stock 4k right now. been meaning to drop it off at the exhaust shop now that its running decent. I was planning on a 2" or maybe 2.25" since the stock downpipe isn't much bigger than 2in. yours sure sounds nice, and I do plan on having some sort of turbo muffler, but I really do need to get that 4k suitcase muffler out of there soon, just haven't made the time yet.

I'd roll with the bigger turbo, and a 2.5" or even 3" downpipe. The bigger one will feel much snappier once it can breathe.

Swank Force One wrote: I'd roll with the bigger turbo, and a 2.5" or even 3" downpipe. The bigger one will feel much snappier once it can breathe.

^yarp.

Turbos do not like da back pressure. Remove it and go as big as you can (3" at least) and plan on doing the downpipe as well at some point. Should only need a fairly straight-through stainless/fiberglass packed muffler to cut the noise a bit. I ran those types of setups on all of my turbo cars for decades and no issues passing noise ordinances or being too annoying.

Swank Force One, and turboswede, The size of the exhaust really doesnt matter for the k24 VS K26 debate. The K24 is just an all around better turbo. Spools faster, flows better, and has a higher useable PSI before turning into a heat pump. The size of your downpipe isn't going to change that.

As for going with a 3" exhaust, there is no point in this on a 10VT engine. The fact is, I will never "over power" the 2.5" exhaust I am running. These engines just dont make enough power. I think they are pretty well topped out at 400HP, and thats with some extremly expensive toys attached, and using exotic fuels.

2K4Kcsq, I think im going to look into putting a lower thermostat in mine as well. Now that I have had more time to tune, and I am able to hold full boost the whole way through 5K, I am starting to see temps that I do not like. It is possible that my CLT driver isnt configured properly, which I am about to go check, but even my IAT's are getting a little on the high side, and I have a fairly large intercooler with good flow to it.

As for the trigger damper, Im going to cut a 45-1 wheel into the center of it. I am using the inner and outer belt, so I have the middle one with nothing on it. I figure why not give it a shot. I know I will have better timing that way, and then I can make sure everything stays consistant.

I think you're misreading what I'm trying to say. It isn't about ultimate power, it's about efficiency. I've run 2.5" and 3" exhaust on 2.5L SOHC 4-cyl turbo motor with the stock (tiny) turbo and it made a slight difference in mid-range power and as a bonus, the noise level dropped a little. Anything you can do to reduce backpressure will help. Period. That 2.5L tops out at around 400hp as well before things have to get really expensive.

What gas mileage do you get with the 4000cs?

This build is awesome! The 4000CS is such a cool car; I was really close to purchasing one but never bit the bullet.

Mr_clutch42: my car stock stayed around 25mpg highway. a friend of mine with an identical 4000s claims she has seen numbers in 28-29mpg range. they are geared rather short so that's one issue with efficiency. im right at 4000rpm at 80mph.

as for the turbo backpressure I know the stock 4k muffler is only hurting right now. I think the plan is to have the exhaust shop bend me a nice 2.5" setup with a "turbo" glass pack. thought about just welding in a straight pipe in place of the muffler for now but I think this engine deserves a nice exhaust. I have already pretty well blown the challenge budget on it so what's a couple hundred for a nice bigger pipe. I don't see myself building a custom downpipe anytime soon but as de80q said, the kkk center housing is only really capable of 350 horse. even when billit wheels start entering the picture your still hanging around 400 so until I go crazy with equal length manifolds and a huge turbo I think the stock downpipe and a nice straight 2.5 exhaust will suit my needs.

the last few days have been spend on the crank case ventilation. I am running a single catch can pulling from the top of the valve cover thru the can to the front of the turbo. seems to be the most effective so far but I still have an intermittent smoke issue. both the checkvalves im using are in good working order but I may ditch them and run a valve-less dual can system talked about here

that's the best source I have stumbled upon as far as explaining the different types of needs for pcv systems.

I heard a bad noise when I started it up this morning, my timing belt idler pulley seems to be walking out of its press fit bore that holds it in the oilpump housing. the noise I heard was it rubbing against the inside of the lower timing cover. pressed it back in but definitely something I will be keeping an eye on. may have to pull it out and locktite it in there if this trend continues.

Didnt you put the bolt back in to hold that pully in place? I almost forgot to put it back in mayself. The pully itself is threaded so you can press it out, but there is a threaded hole behind that you are supposed to put a bolt in to hold the pully in. The press fit on that is very minimal, and is really only there to keep it aligned preperly. It would be a VERY bad thing to have that pully pop off on you. You would need another head

What downpipe are you running now? just a modded type44 piece, or a URQ? The URQ is what I have and it fits perfectly in the small chassis audis. Plus they are basically 2.5". If you are lucky, you might be able to find one dirt cheap as I did, but they can normaly be picked up for around $150.

On a real quick second note, there is no need for 2 catch cans on an inline engine. On a "V" engine, I would consider it. How long did your turbo sit for? Mine sat for almost 5 years, and smoked pretty bad for a while. Now that I have been running it for a while, I no longer have a smoking issue at all, and I do not have a catch can. Just a hose that runs from the VC's "E Hose" to the intake side of the turbo. I have only ever seen smoke come out of my breather system, never anything large enough to actually coat anything with oil. I will eventually get a catch can, but I just got tired of smelling it in the car.

mine is pretty intermittent and it seems to be almost gone with the catch can. every once in a while it will puff a little at idle but nothing like it was. the k24 only sat for like 11 months but the k26 sat for well over a decade....maybe 2 this engine was hauled around on shop floors from one side of Colorado to the other for many years by the previous owner before I got it. seems to be doing alright though.

I'm confident enough in it now to drive it on a much belated trip to vegas tomorrow. this time for battle born quattro 5. maybe 500 miles on this setup and im about to hit the innerstate for 7+ hrs

exhaust is done, fixed the timing belt idler bolt issue, changed the oil, rotated tires. . . . all or nothing like every project I've ever had.

Good luck man, I hope it gets you there and back with no problems. Take some good pics! One of these years I will make it out for that GTG. I just need to get my car on DD status first and work out all the nagging little bugs.

i hear you there. mine is running well but is still having some very annoying issues that seem to be mainly electrical noise. i'll figure it out. but we made it. currently in vegas looking forward to some eye candy in the morning.

btw my down pipe is a stock 5k piece and it fits great. put a small flat spot in the frame rail behind the turbo but that's it.

after attending battlebornquattro for the first time I'm still winding down from it all. making a 7+ hr drive to vegas and back in three days was quite a haul. totally worth it, but next year I will plan better and save a couple vacation days so we don't have to do the event cannonball style. granted the caliber of cars at this event kind of make the whole thing have a cannonball feel to it. . . doing 80 on I-15 only to be passed by a coupe quattro that sounds like an F18 fighter jet will have that effect I suppose. not to mention a high speed cruise thru valley of fire where my 80mph "speed limiter" barely allowed me to bring up the rear. this event is definitely my crowd. power and performance above all else. makes the wuste crowd seem like a bunch of children with their obsession over fitment, stretch & poke, bags and vinyl wraps. . . I like wuste but I don't think it will ever be my primary "go-to" event of the year after going to bbq. anyway, pics.

Damn, I need to make it out there one of these years. I got married out there, and havent been back yet. I love the pic of the 4K next to Jim's "vomit Comet". I love that car, and it was my insperation for a long time, still is for the most part, I just have no plans to make the kind of power he does.

Did you get to meet Hank Iroz? He is a character, I met him at the Carlisle event last year. That would be one that you would like. The Bandit made it's first appearance there this year. Was very un-tuned, but still got there and back.

I have to ask, what do you mean by 80MPH speed limitor? Is that a self imposed limit, or somthing causing it? I didnt think the gearing ont he 016 trans was that short. If that is the problem, you might want to look into swapping the 5th gear from a 5K into that trans. Seems to be the thing to do witht he 016 these days.

Why would you do that? The small chassis 016 has perfect gearing.

Not sure. I know a couple people that have done it now, and they all love it.

Big Jim seems to get around!!! This is my Coupe GT of death, Gregg's V8 90 coupe and Jim's 90 20v vomit comet back in January.....

type85 wrote: Big Jim seems to get around!!! This is my Coupe GT of death, Gregg's V8 90 coupe and Jim's 90 20v vomit comet back in January.....

Damn! Where was that at? I wish he would bring that thing out to Carlisle.

de80q wrote:

type85 wrote: Big Jim seems to get around!!! This is my Coupe GT of death, Gregg's V8 90 coupe and Jim's 90 20v vomit comet back in January.....

Damn! Where was that at? I wish he would bring that thing out to Carlisle.

This was in Long Beach, CA. back in January. Carlisle is a bit of a drive...... about 2,500 miles!!!

Yeah, I know... I would just love to see it in person.

haha thats cool. and yes I would love to make it out to Carlisle one day, quite a haul from western Colorado but someday I will make it out.

as far as the "speed limiter", I have a sync loss issue just above 4000rpm that limits me to 80 in 5th gear. working on it today with some help from the megasquirt support forums. might try a 10k resistor inline with the crank signal. otherwise the car is running fairly well.