Turbo on 320? Is it worth it

[320]

Hi all, I brought my 320 a couple of months ago as my insurance wrote my previous 320 off due to a little bump, I had the other one for about 12 months but the engine started playing up, oil leeks , engine hunting ect... The engine I have in this car seems fine no problems with more miles than the other 1, it has 116000 ish miles, would it be worth putting a turbo on the m20 engine with this sort of mileage or put another newer engine in first to do turbo thing, any advice or opinions good or bad are welcome thanks

[Grrrmachine]

Simple answer is no. For the time and money you'd have to put into it, and the relatively low boost you could run on an M20B20 without killing it, you could pay to put in an M52B28, or an M20B25 with lots of other mods.

Do it to be different, but don't do it for the power; there isn't any. However, it's not an impossible task, but the 320 isn't worth doing it to.

[320]

What sort of power or boost could a 320 push?

[jimmyspeed]

search "m20b20 turbo" there a fair bit on it - I'm currently building a turbo manifold for mine there are advantages and disadvantages (not huge power at the end) but i think mine will be a good torquey street car

http://www.e30zone.net/modules.php?name ... 0b20+turbo

[CHR1S1990]

what year is the car?

[320]

It's a 89 g reg

[CHR1S1990]

so 8.8:1 compression ratio - bang on for a turbo I'd say! same as the late m20b25. If you can spare an extra £300 id get an m20b25 in there and turbo that, if anything just so the turbo comes "in" quicker. If not, just get some ARP bolts on the b20 and you could easily do 300-350bhp. You have a budget?

[320]

I thought the m20b20 was 9.8.1, or is that the earlier model, is right that the lower the compression the better for the turbo mod? If so is it possible to lower the compression on it?

[CHR1S1990]

indeed, earlier (pre 86 IIRC) were 9.8:1. I wouldnt lower it much, if any, more than 8.8:1 as your off boost power and consumption would be crap. Depends on what you want the car for! Drag car, super low compression and mahoosive turbo. Road car Im guessing so there's always compromises. Stock compression, stock headgasket, ARP bolts and a nicely sized turbo would make a nice fun road go'er.

[320]

I had a Subaru forester turbo and that had a compression 8.5.1 so the 8.8.1 isn't that far off and engine was good for 400 bhp.