Cyber's 2001 S4 Build

[Cybersombosis]

I finished the install of the MAP sensor. It went smoothly. Here are some pics.

IMG_3266.jpg

IMG_3267.jpg

I can unhook the MAF connector and swap back and forth at will. We’ll dial in the fueling and max out the OEM MAF first before we switch to speed density.
IMG_3269.jpg

IMG_3270.jpg

IMG_3273.jpg

[CELison]

Do you have to tune around having the map after the TB? Can there be situations at partial throttle where you have higher pressure before the TB and lower pressure after it since the blade itself will be a restriction? If that even matters.

[Cybersombosis]

The tuner says for speed density, the secondary MAP sensor needs to be in the intake manifold. Basically he says that the pre throttle body MAP sensor is acting like a boost sensor or thrust sensor as Bosch calls it so can’t actually measure manifold pressure because it’s pre throttle body, but the post throttle body sensor is truly functioning as a MAP sensor, manifold absolute pressure since it’s installed in the manifold.

As far as the pressure differential before and after the throttle body, he says it’s built into the ecu by default. You need to know the ratio yes and there is situation where thats a factor but it’s nothing to do with speed density.

[CELison]

Gotcha. I didn’t read all the posts. I thought you just moved the map to after the TB.

[Cybersombosis]

Ya the secondary MAP uses the MAF wiring connector. I made an adapter from a spare MAF I had. I didn’t want to snip any wires. I can use the OEM MAF to get the fueling spot on, max that out, then swap over to speed density. One of the reasons for going this route is the limitations on a B5 RS4/B6 S4 MAF up to 500g/s. No limitations with speed density.

[Cybersombosis]

Ok so a small update, I thought I had gotten away with no issues after install of the engine but alas, I wasn't so lucky. Had this annoying oil leak from the first day of install. It would drip down off the turbo and onto the silicone charge piping. Had me baffled for the month I’ve had it up and running. I was like oh crap, hopefully it’s not the oil line feed that's totally hidden. Went in with a bore scope and it was dry, thank goodness. Looked at a banjo fitting and it was covered in oil and thought, voila! Found it. Had a hard time getting to it but got a wrench on it and tightened. I was happy that I found it. Next day the oil is still dripping. WTF? Took the scope out again and had a closer look. I had a DUH moment. The banjo I had tightened was the charge air banjo and of course doesn't have oil. The oil was coming from above the metal coolant pipe between the two heads and it had a drip coming from that area. Turns out the new cam seal I put in when rebuilding the head was faulty. Dripped from there and down the coolant pipe on to the turbo boost reference line for the N75. Luckily I didn’t break the boost reference banjo as it would have been a big hassle to replace it. No more leaks!!!

Another issue I've been having is overboosting. The tuner set me up with a wastegate file and when I went for a pull, it was boosting to well over 25PSI, enough to max out my boost gauge which is just a 2.5 bar sensor. I thought I was only hitting 22PSI but I was losing traction in third on a damp road and after some thought, I just maxed out my boost guage and 2.5bar MAP sendsor. The car felt GREAT and a little scary but great none the less. The tuner immediately told me something is wrong so I had to investigate the next day, albeit a little disheartened. Hooked up my compressor set to 20psi to the wastegate lines and sure enough, HISSSSSSSSSS. Damn, it's down by the turbo. Sure enough after removing the airbox and charge pipes, I found the culprit, a split hose at the wastegate. I don't wish that on my worst enemy.

IMG_3301.jpg

Lots of swearing and busted knuckles later, I finally was able to put a replacement on from my spare engine.

Went out for a test run and now it's behaving properly. I've now maxed out the MAF so that is no longer being used. Speed density her we go. I went out to do a 5 runs for the tuner last night at 10, 20, 30, 40 and 50% WG duty cycle so he can build a linear boost table for speed density. Hopefully that's it for issues and we can get this thing dialed in.

[travis_w]

How was the tuning experience from speed density? I assume the same.

Sent from my SM-S928U using Audizine Forum mobile app

[Cybersombosis]

Ya basically so far I’m having to do multiple runs with specific duty cycles until he builds the grid and figures out the compressor maps then he can dial the tune in. Not much different on my part vs. MAF tuning at this point.

[travis_w]

You still using the stock intake right?

Sent from my SM-S928U using Audizine Forum mobile app

[Cybersombosis]

Ya so far. I haven’t done the mod yet to the airbox. We’ll see how it goes and if it’s a huge bottleneck but if it isn’t, I’ll keep the stock look for the OEM win.

[Cybersombosis]

Small update. The Canadian S4 did not come with HID’s as an option. Apparently I’ve read there isn’t enough crash bar support so the Canadian government made Audi beef up the support and in turn couldn’t use the US fog lights so Canadian S4’s didn’t come with fog lights. For DRL’s, the headlights are energized when the key is on and the headlight switch in the off position with a reduced voltage so halogens were the only option.

I tried upgrading to LED’s but I suspect the reflectors were done so I bought a set of HID clear corner Depos from Unique Style Racing, the same set that ECS has on their website. I had bought a set a few years ago for my A4 for $173 USD and am super happy with them. They went up in price but poor and inadequate lighting is just so disappointing and dangerous at night. I had a set of old HID headlights so I scavenged the ballasts from them to install into the Depos along with new 6000K bulbs. To keep the clear corner look I painted a set of bulbs with high heat silver paint.

IMG_3349.jpg

IMG_3350.jpg

IMG_3377.jpg

Tuning is going slowly. I’m helping the tuner develop and test No Lift Shift and Launch Control so after doing runs to help build the boost table, he’s been concentrating on getting these two options going. I must say that launch control takes the guess work out of launching and I’m super happy with the results. No lift shift is also interesting and I can see how it is helpful keeping the boost and revs up while shifting. Hopefully he will start to turn up the boost soon as I’m currently at around 18psi and am itching to get into the 20’s and start taking advantage of the water/meth to cool the IAT’s as it starts to get warmer out. I’ve already noticed a loss in power as it starts to warm up.

[Cybersombosis]

The tuner has now finished modifying launch control. I asked for flames and he didn’t disappoint. RPM is set to about 5000.

[travis_w]

Who is tuning it?

Sent from my SM-S928U using Audizine Forum mobile app

[Cybersombosis]

A fellow member on the forums with user name Blazius from Romania who has been active on the Nefmoto forums. He has tuned a bunch of my customer’s cars and am helping him develop these types of options. The S4 is a kind of advertising for what he has to offer for tuning so I want to have the full gambit when I take customers out for test drives.

[Audibot]

I've had this tab open in my browser forever! Finally gotten around to reading it.

Great work all around! I appreciate trying to keep interior as stock as possible. Did you/when are you going to address the bell housing?

[Cybersombosis]

Ya I’ll probably keep my eye open for another 01E. If the motor, or should I say, when the motor gets pulled, I’d swap it out. The trans has always been really hard to engage into the gears so there’s something going on there. It makes fast shifting extremely difficult. I’m trying to program myself to pull hard first to second and push hard second to third using no lift shift but sometimes it just misses. If I ever part out another B6 S4, I may do that swap.

As for an update, I’m getting a lot of knock at 18psi, correction factor is at 8 and the tuner is not happy with it. Unfortunately I filled up with our local 91 here and have to burn through that to fill up with Chevron 94. In the meantime he has told me to turn the meth on and after logging a third gear pull, the CF is now down to 3 so hopefully with the higher octane, we can start to turn up boost and add timing.

Does anyone have any experience with knock correction and what they did to get to 28psi and 500awhp? It’s a little deflating to get this far and only be at a fraction of the HP and boost goal and not be able to crank it up. There was another post from Slow-S4 that had knock issues but his engine threw a timing belt and he never updated his thread when he put the new engine in. Any input is appreciated.

[Cybersombosis]

Well I think I found the knock issue. Crap 91 fuel at my local station. I took the fuel rail supply line off and shoved the end into a gas can, connected a pigtail to the fuel pump and hooked up power and drained the entire tank. Put just enough back in to get to Chevron and filled it with 94. Went for a pull and logged it and I’m now at zero CF on knock! Thank goodness! I was beginning to lose hope. Now we can crank up the boost and timing.

[Kamil P]

Nice build! it’s good that you have 94 octane available and the meth injection setup was a good investment. I think for pump gas you already have optimal set up. Even so, you still will be limited by knock. Dropping the compression would have helped greatly


Sent from my iPhone using Audizine Forum

[Cybersombosis]

Ya I’m finding that out now. If I had known, I would have bought spacers/compression lowering head gaskets but I could only glean what I could when I was gathering parts and doing research. Missed that one completely.