Adding HP, advice needed

[etxxz]

4.10 is a highway nightmare...60mph at almost 3000rpm. 75 just over 3.5k, 85 at 4k etc etc etc....still decent mileage but your engine will hate you...i have one but i dont care about my engine, i'm literally waiting for it to start dying so that i can upgrade either cheap stroker or swap.

on the other hand. for a stock m20. 4.10 is probably the single best upgrade you can do, power and money wise. first gear is almost useless for daily driving. i shift out of it ~ 8-ish mph

[StereoInstaller1]

He has a 'vert.

It already has a 4.10

[atomic]

if you crawl under the spare tire trunk area (rear) of your car and look at the back side of the differential there will be a tag on it on the passenger side next to the speedo plug in(electrical connection). It is about 1/2" wide by about 3" long and will have ingraved on it some numbers. If it begins with a " S " it is a lsd and then the numbers will something like 4.10 , 3.73 etc..... that is how you can tell what gearing you have.. You might have to take a rag with you with some solvent on it to wipe it clean enough to read as well...

[GaryE30]

I believe that the 2.5L convertibles got the 3.73 LSD if any at all. The only way it would be a 4.10 would be if it were a 318ic, which its not.

[naika]

Thanks all for the help. I have actually spent quite some money on wheels, new top, new interior (black leather sport seats), drilled/sloted brakes, IS airdam, 1.6 drop in the front, 1.2 in the back. The car is looking pretty good and is completely black (paint, black wheels with chrome lips, top and seats)
It is not a show car but I like it.
I had somebody on here do a VIN decoding and I have an LSD on the car, it runs quite high on RPM to be honest so it must be a 3.73lsd at least but it has some nice power, especially above 4,000 RPM.
I guess I will wait to buy another daily driver and use this one as a weekend/leisure car to mod the engine as it seems like I will have to spend so much more on gas, etc... if I mod it.

I am still learning about all this so all those explanations help a lot.
THanks again

[etxxz]

convertible or not. i'm pretty sure i rear that only automatic 325i's and M3 had the 4.10. manual was 3.73 unless swapped. idk about 318s.

[monty]

well lets see some photos of the beast

[TwoJ's]

convertible or not. i'm pretty sure i rear that only automatic 325i's and M3 had the 4.10. manual was 3.73 unless swapped. idk about 318s.

correct. 4.10 was also a dealer option.