S50 tuning question

[Forcefed]

I started a conversation earlier with @GG///M3 so I already have some good advice, but I would like to get a little discussion going if possible.

I currently have a conforti tune (not sure of the specifics, as I bought the car with it on). Now that I have installed AA race headers (pictures below) and am putting a catless 3" race exhaust on, should I retune the car? I keep hearing that the car will lean out if I dont, but I'm not sure why that would happen. I'm still not that familiar with this DME, so explanations would be appreciated. I can't really find much on this topic, even though I know its out there, so maybe this will help someone else out in the future.

[seth]

yes you will definitely need a retune with catless headers so you can tweak the AFR. Plus if you don't you're losing out on some power you could easily be making from the increased flow.

[Forcefed]

yes you will definitely need a retune with catless headers so you can tweak the AFR. Plus if you don't you're losing out on some power you could easily be making from the increased flow.

Do you know why it would run lean with my current tune? It seems like the O2 sensor would adjust the AFR's just fine.

[seth]

Well it's not like the car is gonna blow up, just saying if you want to optimize the performance and safeguard it a little by adding some coding - tuning it is the way to go.

There are certainly plenty of people who just slap catless headers on and drive away but thats like saying you hire a prostitute to see her boobs and then you're done. Tuning will likely double the gain you'd see with them on - my catless headers made some good power but the tune we added to it made even more good power.

Why only go 1/2 way?

[Forcefed]

Well it's not like the car is gonna blow up, just saying if you want to optimize the performance and safeguard it a little by adding some coding - tuning it is the way to go.

There are certainly plenty of people who just slap catless headers on and drive away but thats like saying you hire a prostitute to see her boobs and then you're done. Tuning will likely double the gain you'd see with them on - my catless headers made some good power but the tune we added to it made even more good power.

Why only go 1/2 way?

Good point. I will likely upgrade the injectors aswell, since the 95 has 17.5lb injectors from the factory.

P.S.

This car is rarely street driven

[seth]

Yeah I'd say thats a great call too.

If you're interested in tuning let us know if we can help you out.


BTW from the pix you have it looks like a pretty awesome ride!

[Forcefed]

Yeah I'd say thats a great call too.

If you're interested in tuning let us know if we can help you out.


BTW from the pix you have it looks like a pretty awesome ride!

Yeah, I'll PM you and see what my options are. Check out my thread to see the rest of the car, if you want (skip to last pages to see the most recent stuff):

http://www.bimmerboost.com/showthrea...ased-a-1995-M3

[Sticky]

Why not just a get a custom dyno tune if you want to maximize it?

[dreikraft]

which DME do you have? 516?

[GG///M3]

If you are not going with Cams anytime soon get a set of 21.5 lb injectors from a s52. They usually go for 50-100 bucks. AA sells a tune for that setup. I had it in my car without a 3inch full exhaust car made 225whp and 214wtq with the stock catback. With a full 3 inch exhaust you should be around 23xwhp with that same tune. You could go with my tuner, and save a good amount of money. He has even done e85 n/a tunes. Tuners nowadays are tuning these cars to 240whp with stock mafs as well. If you plan making this always a track car go with 24lbs injectors, because I can't see you not adding cams at some point.

[Forcefed]

which DME do you have? 516?

I'm not sure, but ill check for you.

Why not just a get a custom dyno tune if you want to maximize it?

This is what I would prefer to do, but I couldn't do it until I have more free time (summer). I'm just trying to figure out if the car will run too lean on the track as is, making a new tune a necessity at this very moment.

If you are not going with Cams anytime soon get a set of 21.5 lb injectors from a s52. They usually go for 50-100 bucks. AA sells a tune for that setup. I had it in my car without a 3inch full exhaust car made 225whp and 214wtq with the stock catback. With a full 3 inch exhaust you should be around 23xwhp with that same tune. You could go with my tuner, and save a good amount of money. He has even done e85 n/a tunes. Tuners nowadays are tuning these cars to 240whp with stock mafs as well. If you plan making this always a track car go with 24lbs injectors, because I can't see you not adding cams at some point.

Yeah, I really should have bought those injectors you sent me. Does your tuner do e-tunes?

[GG///M3]

I'm not sure, but ill check for you.


This is what I would prefer to do, but I couldn't do it until I have more free time (summer). I'm just trying to figure out if the car will run too lean on the track as is, making a new tune a necessity at this very moment.



Yeah, I really should have bought those injectors you sent me. Does your tuner do e-tunes?

If you have a chip burner he can email you the file, and hi 5 all the way to the track.

[Forcefed]

If you have a chip burner he can email you the file, and hi 5 all the way to the track.

Can't say I do haha $$$$. Man, making a lot of power on NA motors costs an arm and a leg. This is why I stick to FI street cars (for now).

[GG///M3]

Can't say I do haha $$$$. Man, making a lot of power on NA motors costs an arm and a leg. This is why I stick to FI street cars (for now).

The chip burner is pretty cheap. I think its about 100-200 bucks, and blank chips are also pretty cheap. I'll post a link to where to buy them here in a few.

[dreikraft]

good to see more s50 projects on BB. here is my beater ass 95 after a few test pulls in various configs. bottom line is with the catback removed lol. IMO not worth the gains cause stupid loud but food for thought if tracking the car.

[GG///M3]

Dude get us a better graph. I'm going to go digging for some of my old n/a graphs to get on here. I'm annoyed I never dyno'd when I had cams.

[Forcefed]

Here is my graph from the previous owner (before bimmerworld throttle body boot, headers, and exhaust)



I believe it was 227whp

[Forcefed]

good to see more s50 projects on BB. here is my beater ass 95 after a few test pulls in various configs. bottom line is with the catback removed lol. IMO not worth the gains cause stupid loud but food for thought if tracking the car.

Mods?

[dreikraft]

just a CAI and my own tune but it still has cats.i love the torque on the older s motors

[GG///M3]

Here is my graph from the previous owner (before bimmerworld throttle body boot, headers, and exhaust)

http://www.bimmerboost.com/attachmen...5&d=1332543064

I believe it was 227whp

just a CAI and my own tune but it still has cats.i love the torque on the older s motors

Which dyno's did you guys use?

[GG///M3]

There is a dyno of my m3 when it was stock

[GG///M3]

That is a dyno sheet with 21.5 injectors, AA tune, AA track pipe, intake, 540maf, stock headers, and stock cat back. IT was a very humid day 93 degree in the summer. Hi 5

[dreikraft]

Which dyno's did you guys use?

DJ

[GG///M3]

DJ

A shop called speed world in Baldwin Long Island from when I used to live out there. I have also another dyno sheet from another m3 I owned, but it was on a dynapack dyno.

[Forcefed]

Which dyno's did you guys use?

Some weird brand, but I know its a load bearing dyno. The previous owner did it.