[recnepswilliams]

I just bought a new daily driver so I can finally start racing my previous daily driver... so now I've got a 1984 BMW 318i, and i know lots of people had performance tips and tricks for my last car that had a small block chevy.

So I'm just wondering if anyone here knows any simple/cheap mods that i can do to get a little more power, the manual of the car says it weighs 2300 pounds, so i don't need much more, it's supposed to have 105hp right now. If i could some how get it up to 140-150 i'd probably be a lot happier lol

but hey, if nobody knows, it's not a big deal, like i said, its a daily driver, i just want to add a little fun to it if i can =P

[sam_bo3]

being a daily driver I assume you aren't looking to do any heavy modding. All internal combustion engines benefit from better breathing and exhaust. I would look at KN air filter, free flowing muffler. With a motor making 105hp stock the exhaust will probably be pretty small. I single 2 or 2.5in exhaust and headers would be the obvious bolt ons.

With such a light car to start with and the age. How is the suspension? A set of coil overs or some Koni inserts for the struts can make a noticable differnce. Poly bushings can really tighten up a worn and tired car.

[ap72]

the same things apply, headers, compression, head flow, cam, intake, and tuning. the easiest way would be slapping on a t25 turbo with larger injectors.

[TurboS10]

http://home.mchsi.com/~jroal/cars/bmw.htm

[recnepswilliams]

the only 2 problems ive got with the turbo idea are 1. the air flow sensor is the vane type, so the way i understand it is that it only measures so much flow and then it's open all the way and any more flow than that is going to be read by the computer as the predetermined max amount of airflow the vane can read, and 2. i think a turbo would take more than just a couple weeks to put on.


I found a set of headers for around $170, and i know of an exhaust shop that would do a full exhaust fairly cheap, but is there much of a chance i could gain anything noticeable through that?

[sam_bo3]

how many miles are the car? If the engine is worn it probably isn't making the factory 105. While 35hp increase with bolt ons is feasible with mustangs and camaros, They are starting off with +300hp. Getting a 30% increase in power is not. With a full exhaust you should feel an noticable difference.

If you are going to spend the money on a turbo system, factor in the cost of a Megasquirt stand alone ECU. If I remember right is bases the fuel needs off the O2 sensors not the MAF. It is fully adjustable with a laptop. Alot of the import guys you this when they want to exceed the parameters of the stock system.

[ap72]

Originally Posted by sam_bo3

If I remember right is bases the fuel needs off the O2 sensors not the MAF. It is fully adjustable with a laptop. Alot of the import guys you this when they want to exceed the parameters of the stock system.

That is partly incorrect. While you can tune with an oxygen sensor the Ms system does not operate off of the oxygen sensor. It can be used to slightly alter the pulse width but MS can also be ran just fine without an oxygen sensor. It operates off of either a MAF or MAP sensor, ignition signal, temp signals, and TPS- very similar to a 90's factory system except that it is MUCH easier to tune.

MS3 is on par with a current OEM system with added control and sensor input, some systems it surpasses with independent injector and ignition coil timing for each cylinder.

[TurboS10]

MS uses speed density so it needs MAP and IAT. Both are easily changed. I think it works most easily with GM sensors which could easily be changed. Like AP72 said, with MS the O2 is only used to makes slight changes in closed loop operation. I dont know if there is a self tuning capability with MS3, but I would not be surprised. In that situation you typically run the car in a tuning mode and allow it to calculate the tables based on input from a WB02 sensor. However, the code to make this happen properly is VERY complicated. IMO, you would be better off just hand tuning with WBO2 and datalog graphs.

I also tend to agree that the turbo is a big jump, but I thought I would post a link since it was mentioned and in that link I believe he used oem parts. I think you could get away with low boost, around 6psi, with the MAF. However, I am far from an expert on old bimmers. There are forums dedicated to them and alot of guys making good power with these old E30's.

[ap72]

Originally Posted by TurboS10

MS uses speed density so it needs MAP and IAT. Both are easily changed. I think it works most easily with GM sensors which could easily be changed. Like AP72 said, with MS the O2 is only used to makes slight changes in closed loop operation. I dont know if there is a self tuning capability with MS3, but I would not be surprised. In that situation you typically run the car in a tuning mode and allow it to calculate the tables based on input from a WB02 sensor. However, the code to make this happen properly is VERY complicated. IMO, you would be better off just hand tuning with WBO2 and datalog graphs.

I also tend to agree that the turbo is a big jump, but I thought I would post a link since it was mentioned and in that link I believe he used oem parts. I think you could get away with low boost, around 6psi, with the MAF. However, I am far from an expert on old bimmers. There are forums dedicated to them and alot of guys making good power with these old E30's.

With tuner studios you can have your MS1 autotune the fuel map with a wideband sensor, hell I used a narrow band sensor to do mine. Yes, I said it a NARROW BAND (shriek! gasp! oh the humanity, hide your wives and children, not the narrow band!). I've had no issues tuning between 12.5:1 and 15.5:1 AF ratios with a narrow band. I used a free 10 year old laptop to do it too.

Oh, and try tuning your MAP fuel map without a TPS sensor, I did, it was a royal pain in the ***. Took the trip to the junk yard and $10 and 10 minutes later I had a throttle body with TPS and it was sunshine and butterflies.


I've been looking into this tunerpro stuff this morning and am VERY confused, it looks like you nee a lot of hardware to make it work, more than the $125-$175 you'll pay for a used MS1.

[TurboS10]

Originally Posted by ap72

With tuner studios you can have your MS1 autotune the fuel map with a wideband sensor, hell I used a narrow band sensor to do mine. Yes, I said it a NARROW BAND (shriek! gasp! oh the humanity, hide your wives and children, not the narrow band!). I've had no issues tuning between 12.5:1 and 15.5:1 AF ratios with a narrow band. I used a free 10 year old laptop to do it too.

Oh, and try tuning your MAP fuel map without a TPS sensor, I did, it was a royal pain in the ***. Took the trip to the junk yard and $10 and 10 minutes later I had a throttle body with TPS and it was sunshine and butterflies.


I've been looking into this tunerpro stuff this morning and am VERY confused, it looks like you nee a lot of hardware to make it work, more than the $125-$175 you'll pay for a used MS1.

NB will work if you can plot the diving curve well enough to make sense of it, but as you well know the WB02 is a better choice. I just pulled datalogs and tuned at the kitchen table between runs with a calculator . I was running VEMS which started life as an MS1 spin-off and went another direction. They beat the MS3 by years to market with a high level controller. But, I would not recommend it to anyone sub-developer-level-intelligent. I was in that group and it was painful on good days.

I think the tunerpro stuff is a little "over advertised" on costs....we'll leave it at that.

[oldbogie]

Originally Posted by recnepswilliams

I just bought a new daily driver so I can finally start racing my previous daily driver... so now I've got a 1984 BMW 318i, and i know lots of people had performance tips and tricks for my last car that had a small block chevy.

So I'm just wondering if anyone here knows any simple/cheap mods that i can do to get a little more power, the manual of the car says it weighs 2300 pounds, so i don't need much more, it's supposed to have 105hp right now. If i could some how get it up to 140-150 i'd probably be a lot happier lol

but hey, if nobody knows, it's not a big deal, like i said, its a daily driver, i just want to add a little fun to it if i can =P

You already know the answer, that's pull the drive line out and put a small block Chevy or Ford in there. In the long haul this will improve the performance, reduce ownership cost, last way longer than anything BMW ever put in these cars, and put a poop eating grin on your face everytime you crank it up.

Contact Mike Knell at JagsThatRun he stuffs Americam V8's in everything he's probably done this and can take you through the drill with minimum effort and cost.

This should get your blood pumping:
http://www.youtube.com/watch?v=7qFrKGSygVM



Bogie

[recnepswilliams]

Well, i just spent 2 days replacing the o2 sensor (stripped the threads out taking the old one out, then re-tapped the hole with the manifold off and reinstalled it.) It's got a little more power to it now.

Now what TurboS10 said, about possibly putting a small amount of boost with the stock fuel injection... Lets say hypothetically speaking i know of a donor car with an intercooler and Garret TD04? i think was what it was. If i connect a multimeter to the maf sensor, and swing the door open all the way by hand and measure the voltage/resistance at max and fully closed, then drive the car and run it wide open until redline, if the resistance isn't all the way to the max, would that mean i can add some boost to it until i was just about up to the maximum measureable flow? Or would the computer not be able to provide more fuel than the most it could require stock?

Or I also read somewhere about the injectors and the time they are open, and that's what determines the amount of fuel, is there maybe a way i can put larger injectors in and adjust the maf sensor so that it takes more air to open it all the way? (it has an adjustable spring inside), then allow the larger injectors to provide enough fuel with the maf closed farther at idle now?

[TurboS10]

I would read through that link and see what he did. Those old computers are pretty simple, so I dont know what kind of tuning can be done for stuff like larger injectors.

Also, Garrett T04, is like saying Dodge pickup; there are about a hundred different flavors that have been made over the years. You need to know the specs to know if it will work. I can help with that if you get serious.