[Zeph]

Originally Posted by Mooreski

Lol, if someone can fit a small block in a Miata, there would be room for a third turbo in a 335!!

True, triple exhaust would look bizzare!

You could triple it to a single muffler and dual it outta the muffler to keep the stock look... not saying this is the most efficient or anything, just saying it wouldn't "look" weird.

[hotrod2448]

Originally Posted by Zeph

Very slightly larger twins would be great for an efficient 400-450 rwhp car for the track with still little to no lag (assuming the wastegate issue introduced in 29.2 is resolved). You could even have a higher boost mode for 500'ish rwhp or so if needed for certain applications (like a drag/highway race). I guess the daily driver would stay with twins too, honestly if you aren't gonna race just pop on an SSTT and go cosmetic from there.

I think the single turbo option is gonna be the best straight-line racing option, with a larger single turbo to make 600+ rwhp (really the sky is the limit here, how fat is your wallet?). With a single I think you can really free up some space in the engine bay and have better cooling and efficiency. Downside obviously is gonna be some low end lag, not really a problem if you keep the RPM's higher. This can actually help launch the car in 1st gear which is the only gear you will ever see low RPM's in a straight-line race.

I can only assume most tuners would come out with upgraded twins first, since less changes to the car would have to be made. Once you go single, now you are basically re-designing the entire intake/exhaust systems.

So many people say a larger single will have more lag but, does anyone really know for sure? Put aside BMW's marketing hype of "two small turbos for no lag" and think about this for a minute. Maybe AMS can chime in with their thoughts/ experience.

You have two small turbos that can flow (I'm pulling numbers out of my ass here) 45 lb/min of air. Each turbo is being fed by half the engines displacement.

Then let's say you have one big turbo that can flow 90 lb/min and is being fed by all 6 cylinders. I'm sure there is some geometry that needs to figured in here given the larger diameter of the single turbo and what not but, provided the mass being accelerated is close to same why would it spool up significantly slower than the two small twins?

I'm thinking you also have to gain a little efficiency (maybe enough to offset the increased wheel diameter) with the single since the frequency of exhaust pulses acting on the turbo are essentially doubled and you don't have another turbo trying to pump against it when it is waiting for one of those pulses.

I think where people get this idea of a single being laggy is from comparing dissimilar turbos. Sure if you take two small turbos that flow 45 lb/min and compare them to a large single that flows 125 lb/min there is going to be difference.

but I could be wrong...

[Eric@AMS]

Thanks again Guys

Two small turbos will get you a decent amount of low end torque but as you are experiencing now they just cant hang on. Putting a larger (maybe gt30R) on the fairly large 6cyl on the N54 would spool VERY quick and hold MUCH better in the rpm band. We will be looking at both options...single and twin.

Keep in mind on a small displacement EVO with a 2.0 liter motor you can achieve 20lbs of boost by 3600 RPM with our turbo kit.

That same turbo on a 2.3 engine will hit that boost level at about 3200 rpm.

now take that same turbo and put it on a motor with over 50% more displacement and exhaust gas...WOW that's a fast spooling turbo.

We could very easily make a single kit spool like a twin and give you more peak power performance

Eric

[oddjob2021]

Originally Posted by Eric@AMS

Thanks again Guys

Two small turbos will get you a decent amount of low end torque but as you are experiencing now they just cant hang on. Putting a larger (maybe gt30R) on the fairly large 6cyl on the N54 would spool VERY quick and hold MUCH better in the rpm band. We will be looking at both options...single and twin.

Keep in mind on a small displacement EVO with a 2.0 liter motor you can achieve 20lbs of boost by 3600 RPM with our turbo kit.

That same turbo on a 2.3 engine will hit that boost level at about 3200 rpm.

now take that same turbo and put it on a motor with over 50% more displacement and exhaust gas...WOW that's a fast spooling turbo.

We could very easily make a single kit spool like a twin and give you more peak power performance

Eric

make it a dual scroll single too !

[Eric@AMS]

possibly, we have done some tests on twin scroll and were not that impressed. We think that the amount of peak power lost from a divided and somewhere restricted housing might not really be worth the small amount of improved spool time to be had.

one thing the members of E90 post will soon find out is we test EVERYTHING! we will not make or sell a product until we know its a good one. This even goes for products that we carry or resell. We strive to be a no nonsense shop that a customer can shop at without ever having to worry if they are getting a good part or not.

Eric

[e90AW335i]

Originally Posted by Eric@AMS

possibly, we have done some tests on twin scroll and were not that impressed. We think that the amount of peak power lost from a divided and somewhere restricted housing might not really be worth the small amount of improved spool time to be had.

one thing the members of E90 post will soon find out is we test EVERYTHING! we will not make or sell a product until we know its a good one. This even goes for products that we carry or resell. We strive to be a no nonsense shop that a customer can shop at without ever having to worry if they are getting a good part or not.

Eric

Very good to hear....

[GQ 335i]

I like how this is going look; we'll be seeing alot more 400+whp N54's around by the way AMS operates. Thank for the support AMS.

[BES335xi]

I dont know if you read page 5. but ...

dont leave us XI guys out.

[scheherazade]

If you go single, just go for a 35r.

There is a version of the 35r with an extra 0.5 inches and is less laggy (I forget he exact name).

I wouldn't mind a twin 30r though...

We need someone to blow up their engine and tell us how it happened. Then we can talk about what turbo we put where.

My first work will be suspension.
My car is going 1 year, or 10k miles. Whichever comes first. Then it's time to do power mods.
If by then you guys have a proven system that's been kicking ass for a few months, and someone has demonstrated the limits of the engine (or at least there are ~reliable power mods well in excess of my plans), then you have a customer.

-scheherazade

[flukey]

Originally Posted by BES335xi

I dont know if you read page 5. but ...

dont leave us XI guys out.

*cough* remember the XIs *cough*

[Eric@AMS]

AWD is in our blood...we could never forget you guys.

Eric

[NM_BMW]

Originally Posted by Eric@AMS

AWD is in our blood...we could never forget you guys.

Eric

Something that everyone tends to neglect.

[Eric@AMS]

actually if there is anyone local with a 335xi we need a car to check clearances on in the near future. please PM me when you can if this sounds possible.

Eric

[Eric@AMS]

Does anyone know what LSD's are offered for the 335i? Is Quaife the only real sollution.

Thanks guys. We have lots of connections with Cusco, Exedy, Carbonetics and OS Giken that might be able to help with this problem.

Eric

[NM_BMW]

Originally Posted by Eric@AMS

Does anyone know what LSD's are offered for the 335i? Is Quaife the only real sollution.

Thanks guys. We have lots of connections with Cusco, Exedy, Carbonetics and OS Giken that might be able to help with this problem.

Eric

I can't help on the LSD since I have an XI, but I just thought of another idea since you guys have those connections.

Make us an aftermarket clutch for us 6MT owners. Not sure if this has been mentioned.

[ironic]

Originally Posted by Eric@AMS

Does anyone know what LSD's are offered for the 335i? Is Quaife the only real sollution.

Thanks guys. We have lots of connections with Cusco, Exedy, Carbonetics and OS Giken that might be able to help with this problem.

Eric

As far as I know Quaife is the only real option. There's also the M (from the m3) differentials and it might be cost effective / worth while to put out a kit that simply allows us to plop that unit on

[Gen_E92]

Originally Posted by Eric@AMS

Does anyone know what LSD's are offered for the 335i? Is Quaife the only real sollution.

Thanks guys. We have lots of connections with Cusco, Exedy, Carbonetics and OS Giken that might be able to help with this problem.

Eric

Quaife is the cheapest and best solution...there're couple others just not worth mentioning.

Also if the diff is welded then you need a complete pumpkin i believe.

[TMR]

Originally Posted by Eric@AMS

Thanks again Guys

Two small turbos will get you a decent amount of low end torque but as you are experiencing now they just cant hang on. Putting a larger (maybe gt30R) on the fairly large 6cyl on the N54 would spool VERY quick and hold MUCH better in the rpm band. We will be looking at both options...single and twin.

Keep in mind on a small displacement EVO with a 2.0 liter motor you can achieve 20lbs of boost by 3600 RPM with our turbo kit.

That same turbo on a 2.3 engine will hit that boost level at about 3200 rpm.

now take that same turbo and put it on a motor with over 50% more displacement and exhaust gas...WOW that's a fast spooling turbo.

We could very easily make a single kit spool like a twin and give you more peak power performance

Eric

Cant wait to see a GT30 or 35 kit for this car. That will be a blast!

[Eric@AMS]

Thank you guys on the differential tips.

My 335i got dropped off last night...time to start tearing her apart

Eric

[JohnnyRingo]

Subscribed!
I can't wait to see what comes out of this thread.

[sublimey]

Quaife is the most affordable one. There's one offered by Active Autowerk too.

[cstmx_ryder]

subscribed