f21L purchase-couple questions...

[04a41975]

Just purchased f21l w install kit for 04 a4 q/tip, which bent valves 3 weeks after i bought it in 9-2015 ($2,600 good shape, tiptronic with 100k...) Found a used 05 1.8(t), 90k miles without turbo ($700) and my mechanic suggested doing new turbo (my choice after much research-f21l), test pipe, dv/splitter while its apart. got that stuff plus purchased gates racing" timing belt kit, new thermostat assembly", fuel filter, 2.0 coil pack conv w hold down kit (all ecs), 18" sport wheels since. Plan on motoza 550 injectors, tune and exhaust but not for a month or two when finances allow... Also torque converter... I like OG's smic so will probably go that route rather than a fmic... Is stock tune ok for now? How much boost can the stock tune produce w the f21l? Will the 17" sport wheels fit the non sport pkg a4 on stock suspension ok? Any other suggestions would be greatly appreciated! Another question is who has a forged engine with a f21l/t or is that even feasible and how much psi could be had with that and awhp and awtq...?

[04a41975]

I may be building the bent valve engine up and if i do just curious what the f21l would do on that. Most likely if i do that i would get a much larger turbo with a roller to put that into... with a manual trans... 2 A4's :)

[walky_talky20]

Just a quick suggestion: if you are going to make lists, it is nice if you put them in a list format. If you want us to read everything, make it easy for us to read. And if you are going to put a bunch of questions in a row, it might be nice to put those in a numbered list or something. I'm just giving some suggestions here.

I'll answer question #3: Yes, 17" Sport wheels will fit a non-sport A4 just fine. The lower profile tires will look funny with all the wheel gap, but you'll get over it. Or you'll get 'moar lowz'.

[jesse500]

Running a 21L, and a bunch of mods on stock software is just silly. Save up until you have $400 for a tune before doing install

[04a41975]

Alrighty ;) one down.

[04a41975]

Running a 21L, and a bunch of mods on stock software is just silly. Save up until you have $400 for a tune before doing install

The f21 is being put in with the test pipe along with the gates timing belt kit and thermostat. I wasnt planning on doing the turbo/dv/test pipe until i was told it would have to be tore apart again when i can do that in a month. I was told its easier to do it that way now and Ill be doing injectors, tune and ic next in a month or two... Is that silly?

[texasboy21]

The f21 is being put in with the test pipe along with the gates timing belt kit and thermostat. I wasnt planning on doing the turbo/dv/test pipe until i was told it would have to be tore apart again when i can do that in a month. I was told its easier to do it that way now and Ill be doing injectors, tune and ic next in a month or two... Is that silly?

See as you are spending some money already, what's another $400 for a tune? Do it right the first time.

[old guy]

See as you are spending some money already, what's another $400 for a tune? Do it right the first time.

X2

[MetalMan]

FWIW I ran my old FT F4H turbo (pre-F21 offering) on my 1.8T on stock tuning/injectors for a couple months. No harm done. I was ironing out various issues and saving up cash.

[theboss]

X2

that sounds like the perfect time to put in an intercooler...
https://www.treadstoneperformance.co...ercooler+480HP

and MetalMan let me know if you ever in NORCAL with that car... Would love to see a FT w/ more POWER

[MetalMan]

and MetalMan let me know if you ever in NORCAL with that car... Would love to see a FT w/ more POWER

That probably won't be for a while, at least until I can get my wife to comfortably drive manual haha. It was up there (on 91 octane) back in Jan. 2015.
Looks like we have moderately similar cars. I'm planning a TR18T in the near future too.

[04a41975]

See as you are spending some money already, what's another $400 for a tune? Do it right the first time.

Well if the tune, injectors and ic were $400 i would do it now. Those things will be over a grand... I have over $2,200 in parts not including the $700 engine i bought... Thanks for your 2 cents though ;)

- - - Updated - - -

FWIW I ran my old FT F4H turbo (pre-F21 offering) on my 1.8T on stock tuning/injectors for a couple months. No harm done. I was ironing out various issues and saving up cash.

Thats a helpful reassuring answer ;) Thanks MM

[04a41975]

that sounds like the perfect time to put in an intercooler...
https://www.treadstoneperformance.co...ercooler+480HP

and MetalMan let me know if you ever in NORCAL with that car... Would love to see a FT w/ more POWER

Im leaning toward one of the smic's... I like the fact that its not noticable ;)

[CardFan]

Well if the tune, injectors and ic were $400 i would do it now. Those things will be over a grand... I have over $2,200 in parts not including the $700 engine i bought... Thanks for your 2 cents though ;)

Are you asking a question looking for input, or looking for reassurance on what you want to do? I went through the same debate before purchasing my F21L. And I didn't want to spend the extra at the time either for the tune, injectors and I/C. But in the end I did, based on the input from this board. If you still want to keep the rest stock, you should at least figure out how you'll address the extra boost from the F21L.

[Matt Devo]

If you still want to keep the rest stock, you should at least figure out how you'll address the extra boost from the F21L.

an MBC in parallel with the N75 and set to the stock wastegate preload (~5spi) would take care of that.

[04a41975]

an MBC in parallel with the N75 and set to the stock wastegate preload (~5spi) would take care of that.

That's what I needed to hear! So 5psi is max for now with a MBC on stock tune? if I got the tune now without injectors and ic wouldn't i have to start from scratch once I put the injectors in, in a month or two?
Seems like a pain for Dave at motoza if I went that route but idk....

[04a41975]

I'm pretty sure there are 500 different ways to go about building a car up and not many people can do it all at once... I'm just asking for advice as to how to go about it with what I have for the time being until I can throw another $1500 into the engine. Some of you are very helpful. Much appreciated

[Matt Devo]

That's what I needed to hear! So 5psi is max for now with a MBC on stock tune? if I got the tune now without injectors and ic wouldn't i have to start from scratch once I put the injectors in, in a month or two?
Seems like a pain for Dave at motoza if I went that route but idk....

using a MBC would allow you to limit boost to stock levels (9-11psi max), so you wouldn't need to get a tune before getting the rest of the components (injectors, FMIC, etc). Once you have everything, then you can remove the MBC and have Dave tune things just like you had installed it all at once.

[04a41975]

using a MBC would allow you to limit boost to stock levels (9-11psi max), so you wouldn't need to get a tune before getting the rest of the components (injectors, FMIC, etc). Once you have everything, then you can remove the MBC and have Dave tune things just like you had installed it all at once.

Ahhhh!!! Tyvm
I'll keep you guys posted.

[04a41975]

using a MBC would allow you to limit boost to stock levels (9-11psi max), so you wouldn't need to get a tune before getting the rest of the components (injectors, FMIC, etc). Once you have everything, then you can remove the MBC and have Dave tune things just like you had installed it all at once.

Would the stock ebc be OK or do I need to buy a MBC before I get the tune? I don't plan on even going over 5k until the tune. I'll definitely be easy on her till then...

[Matt Devo]

Would the stock ebc be OK or do I need to buy a MBC before I get the tune? I don't plan on even going over 5k until the tune. I'll definitely be easy on her till then...

You'll want to pick up a MBC (a cheap spring type one is fine), as the stock EBC (the N75) works in conjunction with the ECU, which expects a certain wastegate spring setting. Since the F21 has a higher wastegate spring setting, the ECU isn't able to control boost via the N75 properly, hence the need for a mechanical override

[userbob0001]

The stock EBC and a MBC are getting boost from the same place. If there isn't enough to open the wastegate, it won't open with either. If there is, it will start opening sooner with the MBC which will slow spool. I'm pretty sure the EBC just opens and closes the line between the turbo and the wastegate and should be fine.

[04a41975]

Thanks for the info fellas 👍

[04a41975]

The stock EBC and a MBC are getting boost from the same place. If there isn't enough to open the wastegate, it won't open with either. If there is, it will start opening sooner with the MBC which will slow spool. I'm pretty sure the EBC just opens and closes the line between the turbo and the wastegate and should be fine.

Thanks! Can you or anyone else elaborate on this a lil more?

[old guy]

You may be fine with the stock tuning for now. Go ahead and try it. If you do find that you are having boost spikes you can control them by running both the N75 and MBC in parallel as Matt mentioned. Set the MBC wherever you need to for spike control.

[04a41975]

Awesome! Tyvm ;)

[04a41975]

One more question... For now anyways lol
What's the advantages of getting 750cc injectors over the 550cc injectors which mostly comes with the motoza tunes? Does Dave tune for those often and would rods be needed if those were close to max? Fuel pump probably needed for those too? Sorry, I'm learning ;)

[cmiguel32]

One more question... For now anyways lol
What's the advantages of getting 750cc injectors over the 550cc injectors which mostly comes with the motoza tunes? Does Dave tune for those often and would rods be needed if those were close to max? Fuel pump probably needed for those too? Sorry, I'm learning ;)

Advantage being that you could get a tune for E85 fuel and 93 octane with 750cc injectors. I have both tunes and the car runs just fine with 750cc's on either fuel. Rods aren't needed, but probably a good idea if you want to take full advantage of an E85 tune. Our stock rods don't like hitting 300 ft lbs of torque especially at lower RPMS. I plan to do rods sooner than later for that very reason.

[G-Ride]

Advantage being that you could get a tune for E85 fuel and 93 octane with 750cc injectors. I have both tunes and the car runs just fine with 750cc's on either fuel. Rods aren't needed, but probably a good idea if you want to take full advantage of an E85 tune. Our stock rods don't like hitting 300 ft lbs of torque especially at lower RPMS. I plan to do rods sooner than later for that very reason.

You beat me to it.

I would certainly recommend getting the 750cc injectors as per Dave's recommendations from the get go. That way you'll have plenty of headroom for and MTC e85 file. I think we hit somewhere near 80% IDC with e85 @ 21psi on the 750's which is moving quite a bit of fuel.

[cmiguel32]

You beat me to it.

I would certainly recommend getting the 750cc injectors as per Dave's recommendations from the get go. That way you'll have plenty of headroom for and MTC e85 file. I think we hit somewhere near 80% IDC with e85 @ 21psi on the 750's which is moving quite a bit of fuel.

Are you running a stock bottom end?

[G-Ride]

Are you running a stock bottom end?

Yep, stock bottom end with 275,000km/171,875mi on it. Does about ~290-300whp on e85. My turbo is the older variant - the F21-L non mixed flow.

[04a41975]

Good info! Thanks fellas. Almost done....