[CptSumTingWong]

i have an 06 330i 6MT and this car feels way slower than it should be...Stock motor but i put in the AT 3.64 rear end in it.

I track the car and it doesn't keep up with miatas and brzs in the straights, I can come out of the turn carrying similar corner speeds and these "slow" cars just walk away.

Even in the turns i get a ton of mid corner understeer that i've been trying to dial out.

On the street or on a back road it feels fine, it's peppy and is entertaining. If you drive it 8/10ths it feels great. But once I push the car to 10/10ths it completely falls apart. I've replaced basically all the normal wear parts, vanos solenoids, disa valves all the gaskets etc and it doesn't throw codes and runs super reliably now regardless of how hard I beat on it, but the performance is very meh.

I know it's not a M car and i'm not expecting supercar performance from it, but this is suppose to be a BMW right? Feels more like a civic...Just feels like i should be able to get more out of it.

I've already thrown some parts at it
3.64 rear end
335i oil cooler
335i front brakes
Whiteline sway bars
Bilstein coilovers
m3 control arms
Dinan camber plates
200tw tires

I'm not chasing the fastest lap times possible, I just want it to "feel" good. I thought it was my driving, but I had the local track pro drive it a few laps and he is obviously faster and cut 4 seconds off my PB, but same issues, understeer and no power.

Am i just expecting too much out of the car and need to reset my expectations? Or is there something wrong with my car or anything else i should be tweaking to make it drive better?

[ppointer]

Something to consider is weight, probably the most important facet of a car (or bike) at the track. The average Miata weighs around 2300 lbs. Your car should weigh in around 3600 lbs. Add in a 200 lb driver (forgive me for making some assumptions). The e90 330 with 255 hp would have roughly 15 lbs per hp to push around the track, while the Miata 4th gen would be closer to 13.8 lbs per hp or so. Not saying your car is not making all of its advertised hp, but even if it is, there is a disadvantage right out the door compared to a Miata.

But track speeds are not just about what happens in a straight line. Weight also comes into play with braking and lateral grip.

I would be comparing it to other BMWs, not cars with a mathematical advantage. Look for other BMW owners at your track events. When they are significantly quicker, get to know them and learn how their car set up differs from yours. Seek out BMW experts, rather than just throw parts at your car.

[CptSumTingWong]

Originally Posted by ppointer

Something to consider is weight, probably the most important facet of a car (or bike) at the track. The average Miata weighs around 2300 lbs. Your car should weigh in around 3600 lbs. Add in a 200 lb driver (forgive me for making some assumptions). The e90 330 with 255 hp would have roughly 15 lbs per hp to push around the track, while the Miata 4th gen would be closer to 13.8 lbs per hp or so. Not saying your car is not making all of its advertised hp, but even if it is, there is a disadvantage right out the door compared to a Miata.

But track speeds are not just about what happens in a straight line. Weight also comes into play with braking and lateral grip.

I would be comparing it to other BMWs, not cars with a mathematical advantage. Look for other BMW owners at your track events. When they are significantly quicker, get to know them and learn how their car set up differs from yours. Seek out BMW experts, rather than just throw parts at your car.

I wish I was only a 200lb driver 😂

I'm also talking NA Miata which is closer to 20lbs/HP. Foot to the floor pretty sure we're about the same speed.

It is a fat heavy car and I'm generally ok with the corner speed I can carry except that I get a ton of mid corner understeer. The understeer is pretty bad and takes away from the overall driving experience. Doesn't need to be tail happy drift car but more neutral would be great. At 8/10ths it drives and balances nicely. But going to 10/10ths is when it really starts to push the front end badly...

The brakes even with the weight are pretty good. I did upgrade to the bigger 335i fronts. But like I said I'm not expecting super car or even "sports car" levels of performance, so the brakes meet or even exceed my expectations.

I almost never see any e90s on track other than m3s which is a different animal and I'm wondering if this is why. I see more e36/e46, but maybe e90 platform just sucks for track work. Kind of why I'm posting this to see if anybody else in a N/A non m e90 has the same issues and if they've managed to sort it out.

Just didn't expect a rwd BMW to drive like a fwd Honda Civic so I feel like I'm doing something wrong or at least have the wrong expectations maybe?

[ptpending]

thats why there is N54 335 with mapping potential
or even better pre-lci 135 N54 manual.
sell you car, add a little and you'll get more competetive car for the track

[CptSumTingWong]

Originally Posted by ptpending

thats why there is N54 335 with mapping potential
or even better pre-lci 135 N54 manual.
sell you car, add a little and you'll get more competetive car for the track

Maybe for a lap or two before you run into heat management issues. I just absolutely railed on my n52 for a 30 minute session in the middle of Texas summer with 107 ambient temp with no issues.

[ptpending]

Originally Posted by CptSumTingWong

Maybe for a lap or two before you run into heat management issues. I just absolutely railed on my n52 for a 30 minute session in the middle of Texas summer with 107 ambient temp with no issues.

they have additional oil cooler and you can try to add one more to other side of the car

[whyzee125]

330's aren't fast cars by any stretch of the imagination, but if it feels slower at 10/10ths and truly can't keep up with a miata in the straights, my best guess would be clogged cats.

[CptSumTingWong]

Originally Posted by whyzee125

330's aren't fast cars by any stretch of the imagination, but if it feels slower at 10/10ths and truly can't keep up with a miata in the straights, my best guess would be clogged cats.

No check engine lights or stored codes though? and still gets great gas milage on the street.

I'm not expecting blistering performance, but yes, legitimately against a stock gen 1 na miata it's about the same speed in the straights...maybe just every so slightly faster but it is very marginal, and against any newer miata or brz forget about it

And I could almost excuse the power if it handled like a miata, it seems to have the right ingredients 50/50 weight, MT, RWD, smooth straight 6 but it understeers like crazy. I can rotate it beautifully on the brakes but once i transition to throttle front end plows and there's not enough power to rotate it on gas.

To be fair, this was a cheap car i bought to teach my wife to drive manual, but now it's a second track car...because i hate money...I just thought it would be a little better

Edit:
I should also add that the gearing on this car sucks. Probably why it feels better on the street, but also why i tried the 3.64 rear end. 1st and 2nd pull decent, but once you go to 3rd it falls flat on it's face. And i'm not comparing stop light to stop light with a miata, it's on a track where you're in 3rd and 4th a lot and it is geared way too high.

[AmuroRay]

Originally Posted by CptSumTingWong

No check engine lights or stored codes though? and still gets great gas milage on the street.

I'm not expecting blistering performance, but yes, legitimately against a stock gen 1 na miata it's about the same speed in the straights...maybe just every so slightly faster but it is very marginal, and against any newer miata or brz forget about it

And I could almost excuse the power if it handled like a miata, it seems to have the right ingredients 50/50 weight, MT, RWD, smooth straight 6 but it understeers like crazy. I can rotate it beautifully on the brakes but once i transition to throttle front end plows and there's not enough power to rotate it on gas.

To be fair, this was a cheap car i bought to teach my wife to drive manual, but now it's a second track car...because i hate money...I just thought it would be a little better

Edit:
I should also add that the gearing on this car sucks. Probably why it feels better on the street, but also why i tried the 3.64 rear end. 1st and 2nd pull decent, but once you go to 3rd it falls flat on it's face. And i'm not comparing stop light to stop light with a miata, it's on a track where you're in 3rd and 4th a lot and it is geared way too high.

No way to honestly tell what's happening without a log or a dyno. My guess is that you need a tune, Cat overheat protection will dump fuel at high temps and bassically cut power on the car, especially when it's hot. Same with timing being pull.

[whyzee125]

Originally Posted by CptSumTingWong

No check engine lights or stored codes though? and still gets great gas milage on the street.

I'm not expecting blistering performance, but yes, legitimately against a stock gen 1 na miata it's about the same speed in the straights...maybe just every so slightly faster but it is very marginal, and against any newer miata or brz forget about it

And I could almost excuse the power if it handled like a miata, it seems to have the right ingredients 50/50 weight, MT, RWD, smooth straight 6 but it understeers like crazy. I can rotate it beautifully on the brakes but once i transition to throttle front end plows and there's not enough power to rotate it on gas.

To be fair, this was a cheap car i bought to teach my wife to drive manual, but now it's a second track car...because i hate money...I just thought it would be a little better

Edit:
I should also add that the gearing on this car sucks. Probably why it feels better on the street, but also why i tried the 3.64 rear end. 1st and 2nd pull decent, but once you go to 3rd it falls flat on it's face. And i'm not comparing stop light to stop light with a miata, it's on a track where you're in 3rd and 4th a lot and it is geared way too high.

You shouldn't be accelerating slower than a BRZ. I was at my local dragstrip one night at a street car night and saw a loud BRZ get absolutely smoked by a manual 90s Ford Ranger lol

Obviously I don't know what's going on with your car for sure but in my experience, clogged cats usually behave exactly like that. Unnoticeable at normal acceleration but makes the car feel gutless at WOT and never had any codes or anything funky

[CptSumTingWong]

Originally Posted by AmuroRay

No way to honestly tell what's happening without a log or a dyno. My guess is that you need a tune, Cat overheat protection will dump fuel at high temps and bassically cut power on the car, especially when it's hot. Same with timing being pull.

Right. If it were dumping fuel for clogged cats I'd get terrible gas mileage. But even on track I'm getting pretty good gas mileage. 8.4mpg indicated absolutely flogging it on track. Little over half tank used in 4x 25min sessions

[AmuroRay]

Originally Posted by CptSumTingWong

Right. If it were dumping fuel for clogged cats I'd get terrible gas mileage. But even on track I'm getting pretty good gas mileage. 8.4mpg indicated absolutely flogging it on track. Little over half tank used in 4x 25min sessions

Cat overheat protection lowers power by dumping fuel to cool the cats, timing is also pulled to prevent the car from detonating the fuel prematurely. These are built into the cars DME by default. Going with aftermarket headers and a good tune would clean that right up and give an additional 20whp.

It also could be coolant/oil overheating. Honestly, there is no way to know without a log - but my guess it's a combination of all three.

For what it's worth, I made 246whp (or 252whp STD correction) and ran a 14 even at 99mph. There are a few guys who can do high 13s and 101. You shouldn't be losing to a miata when it comes to speed.

[AmuroRay]

Reading through yourset up -

Oil cooler: GREAT
Dinan Camber plates - not great. You'll want around 3 degrees of front camber at a minimum. I don't believe Dinan can do that.
Gears: Great - the DME should be updated to reflect the gearing changes.

I would also speak to someone local who can code out some of the safety nannies that might slow you down.

[CptSumTingWong]

Originally Posted by whyzee125

You shouldn't be accelerating slower than a BRZ. I was at my local dragstrip one night at a street car night and saw a loud BRZ get absolutely smoked by a manual 90s Ford Ranger lol

Obviously I don't know what's going on with your car for sure but in my experience, clogged cats usually behave exactly like that. Unnoticeable at normal acceleration but makes the car feel gutless at WOT and never had any codes or anything funky

Drag strips a little different though. You're taking launch into consideration and you're using the lower gears. And was the ranger completely stock?

Brz makes 50-60hp less but is around 800lbs lighter too. Probably geared better and I doubt my car makes all it's power since it's near 20 years old at this point even if refreshed

On a road course track I'm in third and fourth for most of it. The real slow speed stuff coming down into second doesn't feel terrible with the revs up. But coming out of a sweeper in third at say 60-70mph it's absolutely flat.

It's not losing power at wot it's just slow. Looking at some more power to weight ratios I think it's just slow, between that and being geared too high and having wide ratios after second it's probably just what this cars got.

I think I just need to reset my expectations. I knew it's not a m car but just figured it has a bit more out of it... Guess it's just not an "ultimate driving machine"

[CptSumTingWong]

Originally Posted by AmuroRay

Reading through yourset up -

Oil cooler: GREAT
Dinan Camber plates - not great. You'll want around 3 degrees of front camber at a minimum. I don't believe Dinan can do that.
Gears: Great - the DME should be updated to reflect the gearing changes.

I would also speak to someone local who can code out some of the safety nannies that might slow you down.

With the camber plates and m3 control arms im at just over 3 degrees.

I have traction control and stability control off already.

Dme isn't effected by the rear did since it's reading off the wheel speed sensors

[AmuroRay]

Originally Posted by CptSumTingWong

With the camber plates and m3 control arms im at just over 3 degrees.

I have traction control and stability control off already.

Dme isn't effected by the rear did since it's reading off the wheel speed sensors

The first is fine - the ones in bold I'm not sure are correct.

I've been at this a while, one of my buddies on the forum basically deciphered the whole DME. I know for a fact the the DME is looking for a specific final drive, and that even when off the ELSD sometimes kicks in and drags/overheats the brakes.

https://www.e90post.com/forums/showt...1337753&page=2
on cat overheat protection. I'm Taskmasterm HassMachine is the one who decoded the whole DME.

On final drive tuning/Coding:
https://www.e90post.com/forums/showthread.php?t=1257079

I don't remember if the 330i has Elsd though, that you will have to research, but they have a bunch of coding tips on the 1 series track forum

[CptSumTingWong]

Originally Posted by AmuroRay

The first is fine - the ones in bold I'm not sure are correct.

I've been at this a while, one of my buddies on the forum basically deciphered the whole DME. I know for a fact the the DME is looking for a specific final drive, and that even when off the ELSD sometimes kicks in and drags/overheats the brakes.

https://www.e90post.com/forums/showt...1337753&page=2
on cat overheat protection. I'm Taskmasterm HassMachine is the one who decoded the whole DME.

On final drive tuning/Coding:
https://www.e90post.com/forums/showthread.php?t=1257079

I don't remember if the 330i has Elsd though, that you will have to research, but they have a bunch of coding tips on the 1 series track forum

No elsd. I'll check those links out though

[whyzee125]

Originally Posted by CptSumTingWong

Drag strips a little different though. You're taking launch into consideration and you're using the lower gears. And was the ranger completely stock?

Brz makes 50-60hp less but is around 800lbs lighter too. Probably geared better and I doubt my car makes all it's power since it's near 20 years old at this point even if refreshed

On a road course track I'm in third and fourth for most of it. The real slow speed stuff coming down into second doesn't feel terrible with the revs up. But coming out of a sweeper in third at say 60-70mph it's absolutely flat.

It's not losing power at wot it's just slow. Looking at some more power to weight ratios I think it's just slow, between that and being geared too high and having wide ratios after second it's probably just what this cars got.

I think I just need to reset my expectations. I knew it's not a m car but just figured it has a bit more out of it... Guess it's just not an "ultimate driving machine"

Fair enough! I've never driven a 330 on a track but that does sound reasonable.

Also no idea if the Ranger was stock but it looked and sounded like crap so it was hilarious to see it absolutely blow the BRZ's doors off