[herbz]

Not counting suspension, brakes, wheels, tires (as those should be done first).

WHat would be the best option for more power on the E92 335i, after a PROCede and TurboBack Exhaust?? Somewhere in the range of 400+ whp.

With ECU/TBE and 93 oct (which some of us have), we're already at 340-350 whp so that's a good start. But whats next?

People say LSD, but I'm under the impression that LSD primarily helps for turning, not traction. While LSD will be a good mod for auto-X people, it won't help on the drag strip.

Since this car is a turbo, you can look at the downpipe/uppipe. I recall someone saying in a thread that they aren't that restrictive, so adding bigger ones wouldn't net that much power. Is that true?

Would it be best to go straight for a beefier fuel system and larger intercooler? I know this BMW system is probably very advanced and would need some sort of advanced tune to switch out any of the engine parts like Injectors, pumps, pistons, valves, etc.

Thoughts?

Something like a lightweight flywheel would help rev more freely, and also free up 12lbs or so.

Lightweight hood/trunk might free up 20lbs. Every little bit helps.

I don't know, just throwing shit out there, chime in with your ideas/insight and help people understand how they can make more power here.

[07335-06325]

The next things that will be on my list is going to be a better intercooler unless the factory one is that good, and there is enough space in there for a bigger one, and then the fuel system with a very good tune. There really isnt alot to do once you get to around 400 hp to make alot more. Bigger turbos maybe, but i dont think that will happen any time soon. And perhaps a better clutch. Just my .02

[ahnh77]

did you already get an intake?...that should have been before the ecu/exhuast....

for me..i go with:

1) intake
2) ecu
3) exhaust (complete)
4) racing catalytics

after that...you are pretty much looking at larger turbo, larger intercooler, reprogrammed ecu.....

[335boosted2Dmax]

Originally Posted by ahnh77

did you already get an intake?...that should have been before the ecu/exhuast....

for me..i go with:

1) intake
2) ecu
3) exhaust (complete)
4) racing catalytics

after that...you are pretty much looking at larger turbo, larger intercooler, reprogrammed ecu.....

Just summed it up pretty much, probably a short shifter would help too with that light weight flywheel...........but def chip, intake, exhaust, maybe some wider rear tires and light weight BBS rims(18's not 19's if ur serious about it), or if you are really serious, start taking out the interior and unnecessary weight from the car...........larger turbos should hopefully be out by the end of this year or the beginning of next year if we're lucky

[DrM]

Hey, I just wanted to remind you that most of the exhausts currently available connect to the downpipe. The downpipes on the 335 contains cats. No one knows for sure yet, but replacing the factory cats with high flow cats might help. I heard cats can free up 10-20whp on turbo cars. I have heard the high flow cats are about $1200, but I am not positive.

[335boosted2Dmax]

Originally Posted by DrM

Hey, I just wanted to remind you that most of the exhausts currently available connect to the downpipe. The downpipes on the 335 contains cats. No one knows for sure yet, but replacing the factory cats with high flow cats might help. I heard cats can free up 10-20whp on turbo cars. I have heard the high flow cats are about $1200, but I am not positive.

Alot cheaper mod instead of high flow cats is just deleting the cats entirely................

[DrM]

Originally Posted by 335boosted2Dmax

Alot cheaper mod instead of high flow cats is just deleting the cats entirely................

LOL, I agree. But apparently the 335 has O2 sensors in the down pipe both before and after the cats. That might set codes if the cats are missing. Again, I don't think that anyone knows yet...

[335boosted2Dmax]

Thats why people producing a turbo back exhaust that deletes the cats should work with Shiv and a company that can write a program to get rid of the CEL's that would come with the O2 censor readings........

[335boosted2Dmax]

Anyone know why this kid who wrote up this thread was BANNED????? Look under his name, he just joined practically........is there stiff rules on this forum?? sorry to jack the thread a lil...........

[edgarj]

LSD, but that should proably come 1st if I had my head on straight. The bone stock 335i NEEDS a LSD to live up to its potential. It's the one big thing that reminds me that I'm no longer driving an M (aside from the comfy suspension and the FI torque).

[edgarj]

Originally Posted by 335boosted2Dmax

Anyone know why this kid who wrote up this thread was BANNED????? Look under his name, he just joined practically........is there stiff rules on this forum?? sorry to jack the thread a lil...........

I'm very interested in this too... I looked at his posts briefly, and he seems like a typical younger member. I'm guessing that whatever he posted to get banned is deleted, but with some of the insanely racist and profane rhetoric I've seen on this forum, I'm guessing he either posted child pornography or something positive about an Audi

[herbz]

Originally Posted by 335boosted2Dmax

Anyone know why this kid who wrote up this thread was BANNED????? Look under his name, he just joined practically........is there stiff rules on this forum?? sorry to jack the thread a lil...........

Nope.. I just wrote that under my name for the hell of it.

Nice comments guys... good reading. keep with the good suggestions.

What would you guys think about two slightly bigger turbo's? Using this set up would retain the "lack of turbo lag" feel that the N52 has, but would make for some additional power depending on how much larger the two turbo's are.

[335boosted2Dmax]

Originally Posted by herbz

Nope.. I just wrote that under my name for the hell of it.

Nice comments guys... good reading. keep with the good suggestions.

What would you guys think about two slightly bigger turbo's? Using this set up would retain the "lack of turbo lag" feel that the N52 has, but would make for some additional power depending on how much larger the two turbo's are.

LArger turbos probably won't be coming out untill next year..........we would be lucky if a kit came out with larger turbos and intercooler this year.........but yes that is the next move for major power after chipping the car with exhaust and intake

[freddiemac]

Originally Posted by 335boosted2Dmax

Thats why people producing a turbo back exhaust that deletes the cats should work with Shiv and a company that can write a program to get rid of the CEL's that would come with the O2 censor readings........

A straight (catless) large bore downpipe would probably improve the performance more than any other exhaust components. The exhaust right after the turbo should be the most free-flowing part as the exhaust is the hottest.

No programming should be needed, only a pair of O2 housing extenders (go to ebay and search for item # 280081303168) are needed for the factory o2 sensors after the cats.

I'd say the power upgrade order should be:
1) Procede
2) Downpipe
3) Intake (if there's a good solution to replace the factory setup)
4) Exhaust after downpipe with or without High flow cats
5) Intercooler

6) This is actually necessary for road racing: replace the factory manifold and turbos with a larger turbo w/big turbine and high A/R turbine housing and a custom dp. Small and fast spooling turbos by nature has the turbine and exhaust housing designs that chokes the exhaust flow up top in order to get low rpm/load spool. In racing, where most of your times are spent in 5K-7K rpm range, these stock turbo's will trap a tremendous amount of heat. In extended racing, electronic sensors/components will fail due to heat; turbos will fail; exhaust components will crack; engine life is greatly reduced due to the thermo load as well.

I've owned and tracked a couple of twin-turbo RX7's over the last 10 years (with similar small twin turbos design), so I know this for fact.

[DrM]

Originally Posted by freddiemac

A straight (catless) large bore downpipe would probably improve the performance more than any other exhaust components. The exhaust right after the turbo should be the most free-flowing part as the exhaust is the hottest.

No programming should be needed, only a pair of O2 housing extenders (go to ebay and search for item # 280081303168) are needed for the factory o2 sensors after the cats.

I'd say the power upgrade order should be:
1) Procede
2) Downpipe
3) Intake (if there's a good solution to replace the factory setup)
4) Exhaust after downpipe with or without High flow cats
5) Intercooler

6) This is actually necessary for road racing: replace the factory manifold and turbos with a larger turbo w/big turbine and high A/R turbine housing and a custom dp. Small and fast spooling turbos by nature has the turbine and exhaust housing designs that chokes the exhaust flow up top in order to get low rpm/load spool. In racing, where most of your times are spent in 5K-7K rpm range, these stock turbo's will trap a tremendous amount of heat. In extended racing, electronic sensors/components will fail due to heat; turbos will fail; exhaust components will crack; engine life is greatly reduced due to the thermo load as well.

I've owned and tracked a couple of twin-turbo RX7's over the last 10 years (with similar small twin turbos design), so I know this for fact.

Well, the turbos on the 335 are obviously made for low end torque. Look at the dyno graphs from the LA weekend. Almost all of the graphs show the torque graphs dropping like a rock after about 5500 RPM.

http://www.e90post.com/forums/showthread.php?t=46865

I will be really curious to see the new dyno graphs after someone installs a new downpipe with highflow cats and a good cat back exhaust.

[Corey]

Originally Posted by freddiemac

6) This is actually necessary for road racing: replace the factory manifold and turbos with a larger turbo w/big turbine and high A/R turbine housing and a custom dp. Small and fast spooling turbos by nature has the turbine and exhaust housing designs that chokes the exhaust flow up top in order to get low rpm/load spool. In racing, where most of your times are spent in 5K-7K rpm range, these stock turbo's will trap a tremendous amount of heat. In extended racing, electronic sensors/components will fail due to heat; turbos will fail; exhaust components will crack; engine life is greatly reduced due to the thermo load as well.

I've owned and tracked a couple of twin-turbo RX7's over the last 10 years (with similar small twin turbos design), so I know this for fact.

Then you may also know for a fact that the RX-7 uses sequential twin turbos, quite different than the simple parallel twin turbo system used by the 335. At low RPM the RX-7 only flows exhaust through the primary turbo. As rpm and boost rise some exhaust gas is flowed to the secondary turbo to pre-spool it before finally it is fully opened and the system acts like a parallel twin turbo setup. The RX-7 can use two larger turbos than the 335 for better top end without sacrificing low end power. At low RPM only one turbo is used and thus recieves twice the exhaust gas that either turbo would recieve in a parallel system. At high RPM it can take full advantage of having two larger turbos. The best of both worlds, but a very complicated system (http://www.turborx7.com/images/Techn...e_diagram2.jpg <-- a picture if you're interested).

Anyway, what I'm trying to get at is possibly the biggest reason people switch to a big single turbo setup on the RX-7 (and on twin turbo cars like the 335 in general) is COST. Two turbos costs roughly twice as much as one, simple math. Factor in the added cost of another wastegate, plumbing for two turbos, etc. plus the added complication.. many feel the time and money isn't worth it. However, it certainly isn't necessary to go single turbo to make big or top end power. In fact, as the RX-7's sequential system demonstrates, there are distinct advantages to a good twin turbo setup.

[freddiemac]

Yes, I'm very familiar with the sequential turbo systems, having built many different turbo configuration setup, and built many motors myself, I understand it very well. Even with the sequential system physically removed, running the stock twins in non-sequential mode, the thermo load was much greater than running a single turbo with large turbine wheels and large A/R ratio. Unless you have tracked both stock turbo'd and large single turbo'd rx7, you probably won't understand what I'm saying.

Again, I said the need to upgrade to Single turbo is for those who desire to ROAD RACE. not a necessity otherwise. The 335 turbo manifolds are much more efficient than the rx7 ones, however, the small turbine will be come an issue in sustained racing or if you're trying to get 500 hp+ levels.

Originally Posted by Corey

Then you may also know for a fact that the RX-7 uses sequential twin turbos, quite different than the simple parallel twin turbo system used by the 335. At low RPM the RX-7 only flows exhaust through the primary turbo. As rpm and boost rise some exhaust gas is flowed to the secondary turbo to pre-spool it before finally it is fully opened and the system acts like a parallel twin turbo setup. The RX-7 can use two larger turbos than the 335 for better top end without sacrificing low end power. At low RPM only one turbo is used and thus recieves twice the exhaust gas that either turbo would recieve in a parallel system. At high RPM it can take full advantage of having two larger turbos. The best of both worlds, but a very complicated system (http://www.turborx7.com/images/Techn...e_diagram2.jpg <-- a picture if you're interested).

Anyway, what I'm trying to get at is possibly the biggest reason people switch to a big single turbo setup on the RX-7 (and on twin turbo cars like the 335 in general) is COST. Two turbos costs roughly twice as much as one, simple math. Factor in the added cost of another wastegate, plumbing for two turbos, etc. plus the added complication.. many feel the time and money isn't worth it. However, it certainly isn't necessary to go single turbo to make big or top end power. In fact, as the RX-7's sequential system demonstrates, there are distinct advantages to a good twin turbo setup.

[MichaelATL]

Originally Posted by herbz

People say LSD, but I'm under the impression that LSD primarily helps for turning, not traction. While LSD will be a good mod for auto-X people, it won't help on the drag strip.

Hey,

I thought LSD helped on launch too? Does it not give some of the torque to both wheels?

An open diff gives 100% to one wheel. A LSD gives a torque split to each wheel. Am I correct?

Therefore, a LSD would help in many circumstances, especially a launch with a lot of power

...FYI:

I would do this to a BMW 335:

1) Tires/Wheels/Brakes/Suspension
2) PROCede + Exhaust + LSD
3) Done. Anything else is overkill in my opinion.

-Michael

[Corey]

Originally Posted by freddiemac

Unless you have tracked both stock turbo'd and large single turbo'd rx7, you probably won't understand what I'm saying.

Again, I said the need to upgrade to Single turbo is for those who desire to ROAD RACE. not a necessity otherwise. The 335 turbo manifolds are much more efficient than the rx7 ones, however, the small turbine will be come an issue in sustained racing or if you're trying to get 500 hp+ levels.

You don't need to track or even get in the car to understand. It's just math. Road racing doesn't require a huge single turbo. The FD, GT-R, even Porsche have proven this, especially in their new twin turbo setup in the 997 Turbo.

Another system would be the use of variable geometry turbochargers, this system changes the angle of the guide vanes depending on the exhaust pressure giving the system excellent power throughout the rev range. Once used mainly in turbocharged diesel engines, Porsche was the first to use it in a mass-production gasoline-powered vehicle in 2006 with the 911 Turbo (997).

Going to a big single turbo is a way to save money and reduce complexity. It has its benefits, but being the end all of road racing isn't one of them. Maybe you misunderstood me but I certainly don't mean to say the STOCK turbos are more efficient at high rpm than a big single turbo, but an upgraded twin turbo setup theoretically has more potential. We won't know how practical it is until people start doing it though.

Originally Posted by MichaelATL

Hey,

I thought LSD helped on launch too? Does it not give some of the torque to both wheels?

An open diff gives 100% to one wheel. A LSD gives a torque split to each wheel. Am I correct?

Therefore, a LSD would help in many circumstances, especially a launch with a lot of power

You are correct. With an open differential as soon as one tire starts spinning ALL the power goes to that tire. In other words you are only using HALF of your available traction. Weak!

[freddiemac]

Originally Posted by Corey

You don't need to track or even get in the car to understand. It's just math. Road racing doesn't require a huge single turbo. The FD, GT-R, even Porsche have proven this, especially in their new twin turbo setup in the 997 Turbo.

I guess it all makes sense in your keyboard racing experience. But Wrong!!

The new 997 twin turbo is not a track car, try to run that car flat out on the track for an hour session and see what happens. Most 911 based turbo race cars all run much lager turbos than factory, and most of them run single turbos. Most road race FD's were campaigned with large single turbos, if you do your research.

Experience > Theory. Trust me, big turbines = good high end flow.

[BoostedBMW]

^ My friend use to own a 996TT with larger turbo's and currently owns a 996 RUF GT2 and through him and his friends I have seen tons of high HP porsche's, but I have never seen one single turbo conversion. I have even heard of twin GT40's, but never a single turbo on that car. I guess its safe to say that its not common if it is done, and yes, large single turbo's flow more up top, but just because that is the best application for some platforms such as the RX7, it doesn't make it the best choice for road racing in all cars. On a drag strip I could understand, but why would you want the turbo to take a day and a half to spool and hit hard all at once around a circuit?

[Corey]

Originally Posted by freddiemac

I guess it all makes sense in your keyboard racing experience. But Wrong!!

The new 997 twin turbo is not a track car, try to run that car flat out on the track for an hour session and see what happens. Most 911 based turbo race cars all run much lager turbos than factory, and most of them run single turbos. Most road race FD's were campaigned with large single turbos, if you do your research.

Experience > Theory. Trust me, big turbines = good high end flow.

Experience is better than theory, and I'm quoting the experience of JGTC cars over the last decade.

Originally Posted by BoostedBMW

^ My friend use to own a 996TT with larger turbo's and currently owns a 996 RUF GT2 and through him and his friends I have seen tons of high HP porsche's, but I have never seen one single turbo conversion. I have even heard of twin GT40's, but never a single turbo on that car. I guess its safe to say that its not common if it is done, and yes, large single turbo's flow more up top, but just because that is the best application for some platforms such as the RX7, it doesn't make it the best choice for road racing in all cars. On a drag strip I could understand, but why would you want the turbo to take a day and a half to spool and hit hard all at once around a circuit?

So you can spin off the track as soon as the turbo spools coming out of corners?