2.5L engine and CA emissions?

[matt_sienko]

Does anybody know how a 2.5L conversion will work with california emissions regulations?

Dinan makes a 2.5L engine that they say is 49 state legal. That means that it doesn't have a CARB exemption and is illeagal to use on the street here. However, I believe they use a stock US 2.3L engine and change only the internal parts so, even if you check serial numbers, there is no way to tell it is a 2.5L engine without taking the thing apart and measuring it. Others make 2.5L conversions, but I assume the situation is the same.

So, does anybody know if the engine is still within the limits for the stock emissions? Assume the car is OK otherwise and that the engine is near EVO III specs and good for about 240HP at the crank.

Also, does the fact that premium gas out here is only 91 octane hurt anything? Many of the '95 M3s ping on 91 octane.

I'm asking this because I am thinking of getting an E30 M3 and the engine conversion is one of the things I would like to do. I want to find out how difficult it is in my state.

Please share your experience/opinions on this.

Thanks,
Matt

[Bry]

I'm taking an educated guess here but I don't think you would have any problems with emissions AS LONG as you had the car in prefect tune.

E30 M3's can pass emissions tests with flying colors with out their cat converters, the car just has to be in perfect running order and properly tuned.

I don't know if I would go with a Dinan 2.5L, as they do make very high quality products, but it is really an expensive Dinan name that you are paying for. A 2.5L conversion can vary from place to place, and it is really depending on how much money you want to spend. You can end up spending 20k to build the motor up to a 2.5L, some rebuild the bottom end to a 2.5L but keep the stock head. It is all dependent on how much money you are looking at spending. This is to modify your current motor, I don't know if the Dinan motor that you are talking about is pre-built.

I don't believe your 91 octane would pose a problem (I'm not sure here, don't take me up on this) because I think most stock 2.3L motors run fine on it. If you build your motor up to a higher compression ratio (ie more power), then you might have some problems.

If you do get an E30 M3, I suggest you live with the 2.3L for a while, the S14 is a great motor, and it is very capeable. The 2.5L will give more torque, more power, but at a very expensive cost. One thing that a lot of people are doing now is getting a Split Second Stage 2 kit, which replaces the AFM (air flow meter) and can give about 20 hp. The horsepower is not the only part, but lots of torque is gained from this conversion. People say that the around town driveability is greatly enhanced, and they are extremely happy with it. The unit is very cool, it has a lab top port, and you can plug up a lab top, and adjust the fuel maps to get the motor running very well (A plus for your restrictions, as you can tune the motor). This is relatively inexpensive (I think $600 ?) compared to $10k for a 2.5L conversion.

Let me know what you are thinking about doing, are you going to go for a complete overhaul including headwork, valves, cams etc? or just the bottom end? I really think the stock 2.3 is very good in original form, and the Split Second kit really helps the motor out.

What will you be using the car for? Daily driving? Highway driving, city driving? Track?


Read this thread that we had not too long ago about the S14 motor. It has a lot of good information: http://www.bimmerforums.com/forum/showthread.php?s=&threadid=37903

[matt_sienko]

Thanks for the information. I fugured that if the stock engines were fairly clean, then there would be some room for power gains while still being legal. I just didn't know how things would actually play out.

I recently sold my daily driven 95 M3 due to financial constraints. (Ask me how I know abut the pinging.) Now I am thinking about an E30 M3 as a second car to be street driven and to use for track events as well as driver schools.

The 2.5L conversion is definitely down the road a ways. I was actually planning on getting a nice high mileage car and enjoying the 2.3L engine until either it breaks or I have saved up enough to take the plunge comfortably.

I am not sure I would go with the Dinan engine, they just had some good info on their web page. One of the reasons the 95 was so expensive was that I took it to Dinan for maintenence. They are very good and very expensive. Anyway, the reason I was asking was not because I am itching to do a conversion right away, but because I think I will do it someday and I want to make sure I can.

It is still too far out to think about the specifics of the conversion. I would think at least the bottom end plus cams. But maybe once I own the car, the 2.3L will be plenty for me. I have not heard about the split second kit, that looks interesting. The main reason I want an E30 is the handling. Having more power is just a bonus.

[Bry]

Originally posted by matt_sienko
Thanks for the information. I fugured that if the stock engines were fairly clean, then there would be some room for power gains while still being legal. I just didn't know how things would actually play out.

I recently sold my daily driven 95 M3 due to financial constraints. (Ask me how I know abut the pinging.) Now I am thinking about an E30 M3 as a second car to be street driven and to use for track events as well as driver schools.

The 2.5L conversion is definitely down the road a ways. I was actually planning on getting a nice high mileage car and enjoying the 2.3L engine until either it breaks or I have saved up enough to take the plunge comfortably.

I am not sure I would go with the Dinan engine, they just had some good info on their web page. One of the reasons the 95 was so expensive was that I took it to Dinan for maintenence. They are very good and very expensive. Anyway, the reason I was asking was not because I am itching to do a conversion right away, but because I think I will do it someday and I want to make sure I can.

It is still too far out to think about the specifics of the conversion. I would think at least the bottom end plus cams. But maybe once I own the car, the 2.3L will be plenty for me. I have not heard about the split second kit, that looks interesting. The main reason I want an E30 is the handling. Having more power is just a bonus.

I think we all want a 2.5L conversion some day! :laugh

The Split Second kit does help quite a bit on the E30 M3, I would definately suggest you to look into it, as it is pretty cheap, and it gives big gains. It is definately a great mod to do before the 2.5L plunge. The 2.5L stuff is pretty expensive, so be ready to have some money on hand if you are going to do it. Buying a higher mileage car is a good idea if you want to do the 2.5, or even buying a car with a spun bearing, since you could probably get it for cheap, and then have money for the conversion. The stock 2.3 is a great motor, and I'm sure you will be happy with it, there is always stuff you can do to make it better.

Yes, the E30 M3's handling is great. If the car that you buy still has the stock suspension, don't get too upset, there are a lot of things you can do to upgrade the suspension, and really enhance the handling.

Just holler at us if you need anything!

[Bav///Man]

2.5 is definitely a good way to go, but Bry is right as it is very expensive. Isn't the split second kit 1k? I'm not as sure about the second one, but I thought the first one was. For a 2.5 rebuild call Pete McHenry at Precision Performance in Winston-Salem, NC. One of the most respected in the business and he is listed in Roundel. 336-761-0643

[Bry]

Originally posted by Bav///Man
2.5 is definitely a good way to go, but Bry is right as it is very expensive. Isn't the split second kit 1k? I'm not as sure about the second one, but I thought the first one was. For a 2.5 rebuild call Pete McHenry at Precision Performance in Winston-Salem, NC. One of the most respected in the business and he is listed in Roundel. 336-761-0643

I think the SS kit is around 600. I'm not really sure on that though, if anyone finds the website, post it here so we can see.

[badmonkey]

Hmm, like this? :)

http://www.splitsec.com/spike/bmwm3s/MarinoEngMAF.jpg


Split Second E30 M3 MAF kit (http://www.splitsec.com/mafkits/bmwm3/m3mafkits.htm)

I've used their stuff before, highly recommend it.

[Kos-motate139]

Wouldn't the split-second kit allow you to tune the engine for better smoggability? You figure you could set everything for that, get your cert, then go back to your performance settings...?

On www.e30m3performance.com the feller there talks about getting a 2.5 l S14 smogged without any problem. It's probably the condition of the engine and cat more than settings per se.

[phae1017]

I'm a noob at this, what does the MAF kit do exactly, just increase airflow? How does it accomplish this on the s14?:95

[Bry]

Originally posted by phae1017
I'm a noob at this, what does the MAF kit do exactly, just increase airflow? How does it accomplish this on the s14?:95

I'm still trying to figure everything out. There are a lot of aftermarket parts for the S14's for different intakes. The Split second kit replaces the air flow meter ( :mad: ). The air flow meter is like a brick, it slows throttle response, and it really cuts down power. The SS (split second kit) replaces the AFM's (air flow meter) design by using a mass air flow sensor (MAF), which can meter the air, without having to use a gate like the AFM. This really increases throttle response, and gives the car quite a bit of power. It meters the air by a heated sensor that can tell the airflow by resistance? I'm not to sure on that, but it frees up the air flow a lot!

The SS kit also has a labtop port, where you can change your fuel maps. There are thousands of different points in the rev band which you can change the air / fuel mixture, to tune the car just perfectly. This really allows for easy smog passing.

There are other kits, like Alpha-N which are designed more for racing, or higher rpms. Stan, he is on the other boards, is designing a Carbon Fiber intake (it replaces the plenum) designed with some sort of MAF and a piggy back system for the ECU.

I really don't understand everything very well, but I have been trying to read up as much as I can.

[phae1017]

Thanks, "B-money," you font of knowledge!:D

[Bav///Man]

Originally posted by Kos-motate139
On www.e30m3performance.com the feller there talks about getting a 2.5 l S14 smogged without any problem. It's probably the condition of the engine and cat more than settings per se.

The best part is, he isn't even running cats.

badmonkey, I love the separate reservoir for the headlight washers!

[JamesM3M5]

Actually, Gustave does run cats when he needs to get it smogged. Check out the 3" exhaust (http://www.e30m3performance.com/installs/installs-2/exhaust/exh2.htm).

My Evo-2 motor failed VA emissions badly with no O2 sensor in the system. I am going to drill a hole in the Euro header and weld in the proper O2 sensor nut, install, then try again.

[Bry]

Originally posted by JamesM3M5
Actually, Gustave does run cats when he needs to get it smogged. Check out the 3" exhaust (http://www.e30m3performance.com/installs/installs-2/exhaust/exh2.htm).

My Evo-2 motor failed VA emissions badly with no O2 sensor in the system. I am going to drill a hole in the Euro header and weld in the proper O2 sensor nut, install, then try again.

James, how well does your car run without the 02 sensor? Are you still looking into doing the S52 swap?