323i Coupe 1996 pointers?

[Llwyd]

Hello gentlemen (and some ladies I'm sure)

I've been lurking here for a little bit, doing my homework but thought it time to make my first post.

I've recently got myself a 323i coupe which packs the 2.5L engine (M52 or M50?) and I'm itching to start releasing some BHP. Just not sure where exactly to start.

Obviously the main mods are on the cards like new exhaust system, remap, induction kit + manifold and throttle body but I'm lost when it comes to the endless range of extra work I could go for. Things like camshaft and gas flowing. For the 'main mods' i'm struggling to find replacements that have been recommended by people who have a clue (particularly in/out manifolds and induction kit)

To start im obviously going to do the oil, filters, injectors brakes but I want to replace the ignition system and im having trouble sourcing suitable leads Also recommendations on a new battery would be much appreciated.

I've not stated a budget as this will be done straight out of income over a little while so I dont get carried away haha. So yea, any advice and pointers will be greatfuly recieved

 

[turbonutter69]

Hello gentlemen (and some ladies I'm sure)

I've been lurking here for a little bit, doing my homework but thought it time to make my first post.

I've recently got myself a 323i coupe which packs the 2.5L engine (M52 or M50?) and I'm itching to start releasing some BHP. Just not sure where exactly to start.

Obviously the main mods are on the cards like new exhaust system, remap, induction kit + manifold and throttle body but I'm lost when it comes to the endless range of extra work I could go for. Things like camshaft and gas flowing. For the 'main mods' i'm struggling to find replacements that have been recommended by people who have a clue (particularly in/out manifolds and induction kit)

To start im obviously going to do the oil, filters, injectors brakes but I want to replace the ignition system and im having trouble sourcing suitable leads Also recommendations on a new battery would be much appreciated.

I've not stated a budget as this will be done straight out of income over a little while so I dont get carried away haha. So yea, any advice and pointers will be greatfuly recieved

First of all Welcome to Torque Cars buddy. Second supercharge it. :bigsmile::bigsmile:

 

[obi_waynne]

A spiral flow in the head can make pretty good power gains on those. Try Autocustomegnineering who is on here and I'm sure he can sort you out with some good prices.

A lot depends on what you want to do with the car. Is it going to be a fast road daily drive or more of a weekend fun car with some trackday use?

As far as your list goes i'd do the remap last and get a custom map to take into account all of the other mods. Start with the breathing (induction kit and exhaust) then phase 2 can include the head and cams.

Have you thought about adding Nitrous? It gives a big back for your money.

 

[Llwyd]

A spiral flow in the head can make pretty good power gains on those. Try Autocustomegnineering who is on here and I'm sure he can sort you out with some good prices.

A lot depends on what you want to do with the car. Is it going to be a fast road daily drive or more of a weekend fun car with some trackday use?

As far as your list goes i'd do the remap last and get a custom map to take into account all of the other mods. Start with the breathing (induction kit and exhaust) then phase 2 can include the head and cams.

Have you thought about adding Nitrous? It gives a big back for your money.

Thanks for the fast response fellas.

Yea supercharger and nitrous have crossed my mind but think theyre a bit more effort than theyre worth on a fast road car (to answer your other question)

By 'spiral flow in the head' do you mean those induction tubes with a spiral / rifling running down the length of them? I know going too big with the induction system is a bad thing but how big is too big? Really the only difference I can see between them is price at the moment :sad2:

And with the manifolds, as its the M52 engine am I right in thinking I can only use the higher flow M50 manifolds if its the single VANOS engine? If so, would the M52 2.8 manifolds be any bigger?

Also does anyone know why im finding it impossible to find any aftermarket ignition leads for the car? all the E36 ones I find are listed as for the 316 and 318 only

 

[obi_waynne]

Spiral flow is more subtle, airways are crafted and sometimes a lobe is added to the inlet port to encourage the air/fuel mix to spiral into the cylinder. It results in a cleaner burn and more power.

Can't help with manifolds I've never looked at these myself on the M52. What you say does sound right though.

 

[Llwyd]

Spiral flow is more subtle, airways are crafted and sometimes a lobe is added to the inlet port to encourage the air/fuel mix to spiral into the cylinder. It results in a cleaner burn and more power.

Can't help with manifolds I've never looked at these myself on the M52. What you say does sound right though.

Ah right so its more to do with creating turbulence in the inflow? I know that its a good idea to leave the inside of inlet manifolds pitted and rough to increase turbulence and improve particularization of the air.

I'll look into that mate thanks

 

[obi_waynne]

Turbulance is probably the wrong word. You are aiming to flow the air smoothly but get it to swirl into the cylinder. Turbulance technically slows down the air flow whereas a spiral flow mainly changes the direction of flow.

 

[steerfromtherear]

Your car will be a m52b25 which is the 2.5 323i. You want the m50b25 inlet manifold but it is not a direct fit. There are a couple of people who sell them modified for bolt on kits or there are one or two guides on the net to mod it yourself.
Search for Alpina527 on www.bmwowner.com if you want to purchase the ready to go kit (he does Big bore throttle bodies too).

Its been proven time and time again by owners of e36 323 and 328s that M50 mani, BBTB, Decent induction kit (Gruppe m replica, Simota, Dave F), and a remap will work very well at freeing up the m52 motors. 323's get 200-210 hp out of this, 328s will see 220-230.

Stock BM exhausts flow good so stick with decat for powers and back box for looks unless you need to replace your exhaust.

 

[Llwyd]

Your car will be a m52b25 which is the 2.5 323i. You want the m50b25 inlet manifold but it is not a direct fit. There are a couple of people who sell them modified for bolt on kits or there are one or two guides on the net to mod it yourself.
Search for Alpina527 on www.bmwowner.com if you want to purchase the ready to go kit (he does Big bore throttle bodies too).

Its been proven time and time again by owners of e36 323 and 328s that M50 mani, BBTB, Decent induction kit (Gruppe m replica, Simota, Dave F), and a remap will work very well at freeing up the m52 motors. 323's get 200-210 hp out of this, 328s will see 220-230.

Stock BM exhausts flow good so stick with decat for powers and back box for looks unless you need to replace your exhaust.

Thanks mate, i've contacted him and looks like a good deal for the bbtb and modded manifold. Induction kit will come after ive changed the manifold then just got to find someone to do the remap

If anyone knows anywhere in or around SE wales / the west who would be up to doing the ECU would appreciate a contact

 

[obi_waynne]

Let us know how you get on with the parts and how much of a difference it makes.

 

[Rudders666]

Your car will be a m52b25 which is the 2.5 323i. You want the m50b25 inlet manifold but it is not a direct fit. There are a couple of people who sell them modified for bolt on kits or there are one or two guides on the net to mod it yourself.
Search for Alpina527 on www.bmwowner.com if you want to purchase the ready to go kit (he does Big bore throttle bodies too).

Its been proven time and time again by owners of e36 323 and 328s that M50 mani, BBTB, Decent induction kit (Gruppe m replica, Simota, Dave F), and a remap will work very well at freeing up the m52 motors. 323's get 200-210 hp out of this, 328s will see 220-230.

Stock BM exhausts flow good so stick with decat for powers and back box for looks unless you need to replace your exhaust.

Hi Guys. It's been a while since I was on here but i'm still tinkering with MY 323i Coupe as well. I've got the angel eyes, some new alloys etc. I've had a fairly recent service so all that's up to date, I just require a bit more oomph. I bought a manifold from the scrapyard. I removed it from a 325i as these are the larger manifolds so i'm reliably informed. You mentioned it's not a straight fit onto the 323i and i'm intrigued as to the difference as they look about the same under the bonnet. Any help and any kind of idea on gains i should be achieving would be much appreciated. Many thanks for your ideas and suggestions.

Pete

 

[MasterAuron]

Get some pics up youth! Just a quickie, with regards to the Nitrous, it's suprisingly easy to fit an can probably be done yourself in about an hour if you're handy with a spanner.

 

[Rudders666]

I've got some pics of mine on. But i'm guessin you meant the other guy. Are there any drawbacks to nitrous?

 

[obi_waynne]

The only drawback I see on Nitrous is having to get the bottle refilled. It really is pretty easy to bolt on and gives a decent power shot. I'd stick to 50bhp shots as a max on a stock engine your size.

Check the manifold against the gasket and make sure all the ports line up. I guess the ports on the 325 manifold is bigger which is good. You could always polish up the inside with a grinding stone & Dremill like I did on my 220Gti's manifold.

 

[Llwyd]

Hey guys. Ive done quite a bit of work on it recently, i'll get some shots up soon.

The main problem with replacing the inlet manifold is the piping. The older manifold has less holes on it than the ODBII one, so you need to knock up some new hosing with T / Y connectors in it. The gasket is slightly different (no biggy) and you need to splice two throttle body manifolds together for the body. Mounting brakets need a little bend and the fuel rail needs a few little bits popped off but thats it With an M50 manifold off a 328 M50 onto a 328 M52 you can expect to see about 12bhp, so slightly less on a 323i. When done with a bored out throttle body and a nice fat induction kit, more in the riegon of 25-30 Toss in a re-map and youre laughing

I'm looking at NOS systems at the moment. Once ive done all the above it will be a case of underdrive pulleys and radiator fan removal, weight reduction and nitrous

 

[obi_waynne]

I look forward to seeing your pics. It sounds like your almost finished.

 

[Sid447]

I'm not convinced,

about bigger throttle-bodies and larger diameter intakes for these engines. Though I will happily conceed if someone can show a validated before and after dyno graph for this mod.

A performance chip works okay with these. As does a good Cold Air Intake that is blocked off from the heat under the bonnet (hood).
Also a six-branch exhaust manifold (headers) of the type that are designed like two 3-into-1s which stay separate until merging under the car by the transmission (better torque).
Supersprint, Bonnini & Alpina used to do these though they are not cheap. They change the sound considerably and were good for a gain all through the rpm range and made 10-12hp @ peak rpm on an M20 B25 (2.5L) engine.

Good quality tuning parts for BMW cars are not cheap. There are many places that offer tuning work but it would be best to ask for validated proof of their work before buying.
If they are a professional concern they will be more than willing to show valid, properly corrected (as opposed to fudged figures) comparison dyno information etc.
Research the subject on google or something and check out The reputable companies like Racing Dynamics, Schnitzer, Alpina, Dinan, Bigazzi, Hartge, Birds etc.

 

[Llwyd]

I'm not convinced,

about bigger throttle-bodies and larger diameter intakes for these engines. Though I will happily conceed if someone can show a validated before and after dyno graph for this mod.

A performance chip works okay with these. As does a good Cold Air Intake that is blocked off from the heat under the bonnet (hood).
Also a six-branch exhaust manifold (headers) of the type that are designed like two 3-into-1s which stay separate until merging under the car by the transmission (better torque).
Supersprint, Bonnini & Alpina used to do these though they are not cheap. They change the sound considerably and were good for a gain all through the rpm range and made 10-12hp @ peak rpm on an M20 B25 (2.5L) engine.

Good quality tuning parts for BMW cars are not cheap. There are many places that offer tuning work but it would be best to ask for validated proof of their work before buying.
If they are a professional concern they will be more than willing to show valid, properly corrected (as opposed to fudged figures) comparison dyno information etc.
Research the subject on google or something and check out The reputable companies like Racing Dynamics, Schnitzer, Alpina, Dinan, Bigazzi, Hartge, Birds etc.

There are many many dyno results for them mate. I wont link though as they are on other forums.

Cant chip the 323i '96 onwards. Only remap As for the exhaust, the M52B25 has two 3-1 manifolds with two downpipes. Cat is 1 pipe but im swapping mine to a 2pipe 328 cat and two 318 silencers.

 

[turbonutter69]

There are many many dyno results for them mate. I wont link though as they are on other forums.

Cant chip the 323i '96 onwards. Only remap As for the exhaust, the M52B25 has two 3-1 manifolds with two downpipes. Cat is 1 pipe but im swapping mine to a 2pipe 328 cat and two 318 silencers.

You can get a custom chip for just about any car nowadays. All you have to do is find someone willing enough to program it for you.

 

[pgarner]

yeah people just wont chip them as the remaps is alot easier to do as they board doesnt need pulled apart and resoldered

 

[Sid447]

From '95 on BMW,

IIRC, went OBD-II.
Which means the PCM (auto) or ECM (manual) gets re-flashed through a cable from either a lap-top or special hand-held programmer.
There is no need to touch the Control Module. It's just re-programmed with different parameters to improve timing and fuelling plus many other things to suit the car in question.
It takes about 5 minutes (with the ignition keyed "on") while the new tune is down-loaded. Once the download finishes, the ignition is turned off for the PCM to re-boot itself; and that is all there is to it.
You then just start and go. Some parameters like fuel trims take a few days to settle but apart from that it's very straightforward.

Before that ('95) it was of course OBD-I which was the chip replacement type of ECU that had to be physically worked on to replace the main removable control chip. Which in the Bosch Motronic range that I knew were 28-pin jobs that weren't soldered in place but nevertheless had to be carefully removed and replaced (the pins were very easily bent out of shape if you weren't careful) with a modified chip and then the ECU was re-sealed and re-installed in the car. Then you were good to go.

 

[pgarner]

so i take it you cant chip the newer ones then ?
i know alot can still be chipped but just about all are done by remap through the obd2 port mostly its down to time and ease of doing. like youve said 5 mins to load a generic map or maybe 45mins to pull the ECU and fit the new chip

 

[MasterAuron]

Before that ('95) it was of course OBD-I which was the chip replacement type of ECU that had to be physically worked on to replace the main removable control chip. Which in the Bosch Motronic range that I knew were 28-pin jobs that weren't soldered in place but nevertheless had to be carefully removed and replaced (the pins were very easily bent out of shape if you weren't careful) with a modified chip and then the ECU was re-sealed and re-installed in the car. Then you were good to go.

Punto GT's run Bosch Motronic, hence replaceable EPROM. Must've took me all of 20 minutes to swap my chip over.

 

[Sid447]

Punto GT's run Bosch Motronic, hence replaceable EPROM. Must've took me all of 20 minutes to swap my chip over.

Yes,

agreed. The Motronic chip in my old Beemer took about the same amount of time once I'd got used to it. But the frustration was that the chip was "set in stone." Pre-programmed for a certain model. Unless you dyno'd the car extensively and paid for one to be tailor-made for the particular car.
Which is what was done for a friend's M3 once.

But with the appropriate OBD-II software package now in my case it takes all of two minutes for a re-flash of over 600 finitely variable parameters that can be changed (or experimented with) and can even logged as you drive with real-time monitoring (on a lap-top for example0 to see the effect of the changes made.
There's also an option of making real-time changes to the tune as you drive.
(This is for a GM OBD-II vehicle).
I'd imagine there must be something similar available for BMW and other makes.

 

[Rudders666]

I've just modded my 323i. I needed a flywheel as mine was squealing constantly. I elected to buy a friend of mine's 328i he wasn't doing anything with. I had his flywheel, high-speed-gearbox and engine fitted into my 323i! The gains are unbelieveable!! I am immensely happy with my new ride. No more waiting for the power to kick in in higher rev's. It's just foot down and gone! I love it! If you can find a 328i i suggest you buy it and mod it into your current 323i if the body work's better! Sex on wheels! lol!

Disclaimer: I'm sure this may be of no help at all, i'm just overly pleased with mine. lol!