AFN light mods and expectations

Hey there, first time posting so if there are any issiues I'm sorry. I have a 1998 A4 B5 afn quattro which I had tuned. The car "woke up" quite nicely but it wasn't long before I started wanting a bit more from it. So far I've installed a gt1749va turbo and 0.216 injectors from a 5 pot 2,5 TDI. The car has stock exhaust with a cat delete and I'm considering a muffler delete as well. My question is what should I expect power wise and should I start worrying about the clutch. The car has been full serviced since I bought it(belts, oil, filers, clutch, etc...).
Here it is:

4/5 of an equivalently tuned AEL would be a good starting guess...

supper nice, im jelly

so if you want some decent power, just replace and upgrade the clutch, get it over with, its not that hard of a job really, just lots of things to do and a weekend of time. Upgrade the fork when your in there, i put some extra welds on mine as they tend to bend under better clutches.

sky is the limit after that. Or you can just up the nozzle size and then change the clutch after you did not much power, its not that much you need to blow it. Clutch is cheep , half the cost of my tune lol.

Thanks for the responce. I'm not actually going for an all out performance project. The car is my daily and I wanted to make it a bit more enjoyable to drive, not that it isn't at the moment. Maybe I should have cleryfied that my worry is if the clutch will give up after the car is tuned with the new setup. Not that its a problem to upgrade it but if it can handle the power why bother. I have laying around a single mass flywheel from a b4 1z tdi and an upgraded pressure plate.

light mods will be fine, the best bang for your buck is get more high end with less focus on low end that will kill the clutch, your clutch should be able to handle some light mods, up your fuel with a 2nd stage nozzles, down pipe up the boost a few psi maybe and see how you like it, then get a tune.
my clutch stated to slip once i put on my gt2052 and a set of pp.764's. so id say just go with the next size up on your nozzles than stock with a tune. A better upgrade is all around is a bit into suspension to get a bit stiffer for corners with out going wild and sacrificing on comport. The #1 thing you should do is get a EGT temp probe and gauge and an oil PSI gauge, i recommend Auber digital set, well worth the insurance if you go big on fuel as you want to make sure you dont exceed EGT's. If you spend the money on a turbo, its well worth it for the insurance to make sure it gets enough oil and does not overheat. im glad i did and they can be wired up as they have relay's in them for things like water meth injection or other things.

as for keeping it simple, a 1 stage up on nozzles and a tune would probably be best and you would not need any gauges for that!
once you get more power, you always want more

one suggestion i have for you is to find a local autocross, its more fun than you could ever imagine and you dont need a fast car for it, tires help

Your AFN should be mated to a 5 speed 01A like mine. It will work fine with a single mass flywheel, unlike an 01E, which will destroy the synchros with a SMF fairly quickly. I replaced my original clutch with a Valeo OEM replacement SMF kit and while it's OK, I preferred the NVH with the DMF and had I known it at the time would have stayed with the DMF. As it turned out, the original clutch was actually still reusable but the pilot bearing had disintegrated, so I spent several hundred dollars in a complete clutch kit and labour to replace a two dollar part...

If I ever upgrade to a 6-speed 01E, I'll return to a 240mm Sachs SRE DMF kit.

Incidentally my car has stock injectors and turbo, but has a 12mm pump and is remapped, so it should develop about the same power and torque as yours. While the clutch was slipping during winter when it was newer, it's not anymore.

Best bang for buck: Bosio race 520 nozzles, 11 mm pump, Bv 43a turbo cartridge in bv43 housings (from the 2.0pd tdi), catalytic converter delete pipe off eBay, stronger clutch and proper map and it will piss all over corrado vr6 ! I had an old a4 FWD, engine code AHH. It comes stock with 90 Bhp, VNT turbo gt1749v just like the AFN, and flash trough obd ecu. With bosio race nozzles and gt1749va turbo it ripped the flywheel to pieces and clutch was slipping big time. I then put a bv43 and it was a bit more sedate but had a much stronger top end. I did not had a chance to tune the engine further as I crashed the car and decided to break it for spares. It was a vicked car to drive !

Ive crashed my car 4 times, every time resulted in the welder coming out, a trip to the junk yard, and a $50 tow home and it was always ripping tires the next day! or in 2 days, like when i slammed a curb at 45mph at a 30* angle and ripped the lower control arm OFF.

OP wants a config that wont need a new clutch, so your set up is a bit much! but sounds like a great combo.

See my signature, my AFN is close to 200 crank hp - but yes a clutch upgrade needed.

Whats the bv43a cartridge mod? Mine runs 1.8bar happily - does this mod allow higher boost again? Or just better spool?

Just better spool ! The bv43a does have a billet compressor with nice trim, extended tip technology and fits plug and play into the bv43 pd 2.0 tdi housings ! It allows 220 British horse power if you have fuel to go with with reasonable EGT !

Mongler98 said:

Ive crashed my car 4 times, every time resulted in the welder coming out, a trip to the junk yard, and a $50 tow home and it was always ripping tires the next day! or in 2 days, like when i slammed a curb at 45mph at a 30* angle and ripped the lower control arm OFF.

OP wants a config that wont need a new clutch, so your set up is a bit much! but sounds like a great combo.

Click to expand...

After you had Quattro it’s hard to go back to FWD no matter how good is the car ! I still have a 1.9 tdi Quattro with a built engine (ported heads, twin valve spring setup, stronger rods, etc.) but the car is not in the best shape...needs tracking, some paintwork- just lost interest ! As you grow old it’s just easier to save up and buy a new car with a little bit more power !

adamss24 said:

British horse power

Click to expand...

WHAT?

Horsepower (hp) is a unit of measurement of power (the rate at which work is done). ... Two common definitions being used today are the mechanical horsepower (or imperial horsepower), which is 745.7 watts, and the metric horsepower, which is approximately 735.5 watts.

I guess American horses are stronger than your British horses!

Mongler, i was just being sarchastic... Yankees use wheel horse power and on the continent we use brake horse power... I was hinting at Ben_ as he is british and understands the pun. I am not british though...
Some say the stronger horses are italian, spanish or portuguese... These folks cars havr most Bhp on their dyno's, must be the mediteranean sea breeze!

Thank you for all of your responces but a problem has come up. The car is over boosting like its seems nothing is controling the boost. Tried swapping the n75 with a working one my tuner keeps for cases like this but it was still the same. The turbos geometry seems to be working(before installing it was disassembled and cleaned up) but the car spools late and it then bogs because the computer cuts it off. Could something be wrong with the turbo or could it be a vacuum line problem?

It's a 20 year old car - rubber vacuum lines could be hardened and porous. If you have a hand-held vacuum pump, you can disconnect the line between the N75 and turbocharger, apply vacuum and see whether the vacuum holds, ie whether the gauge moves. Repeat from other vacuum lines. Also check for fault codes in the ECU. They will give you a clue of the culprit.

Checked the whole vacuum system no leaks no nothing, my valves work and I'm gona take the turbo out again. I can't seem to find another issiue so disassembling the turbo is so far the only option I can think of. Has any one had a similar problem??

Are you still on the standard and original 2.5bar MAP sensor?

did you replace the lines? Did you test them? just because they test ok, does not mean that old dry rotted lines wont leak when running and shaking about. replace all your lines one at a time, with either oem or silicone high quality lines. clean out any oil that may be building up in said lines, check the air box for oil drips from the lines and same with n75 valve. I am highly suspect of your MAP sensor. i think your ecu is not getting the right values for the turbos work. either MAP or lines.

It is the stock map, but if its malfunctioning there should be an error code on the diagnostics and it should not read any values. The only fault code it had was from the overboosting, the map still read values when we tested and it went up to 2570mbar and if you held it longer it would bog down. I don't think it is from the vacuum lines because the car ran fine before the turbo swap. It doesn't make any sence, and yes all lines were tested, there was no oil in the system and there weren't any clogged lines.

Stock map with a changed turbo config,
isnt this the issue? how would a turbo act up like this?
Try using a manual override on the boost controller and see if it changes, if so, well you need a new or upgraded MAP and a tune.
dont quote me on that, but thats what im leaning towards

I'm trying to source a 3 bar map from a 2.0tdi. Thought it should work with my stock one since the gt1749va runs at 1.3bar from the factory on the 1.9/2.0pd but I guess this could be the problem

well, i ran 29 PSI on my ahu with the stock MAP, i kept having limp mode but that was it, besides lower power that i should have had, tune was obvious but i was out of $ so i ran with it for years, i never had this issue you are having though.

Obviously swapping to a 3bar MAP sensor from 2.5bar needs a calibration change, otherwise you'll overboost without knowing....

If you changed the turbo and kept the map stock then the turbo is your problem- either the mechanism is binding and doesn’t respond as per ECU requests or the vacuum layout is somewhat disturbed...I would simplify the vacuum pipes- disconnecting egr and see if it improves...
As per above, a 3 bar map sensor needs calibration in the tune, it will work but will spike at times !