My first ever M20 budget turbo build

[soltani]

What's up dudes!

I am looking to have fun with my '92 vert with an m20 motor that has been rebuilt not too long ago. I have a general idea of the things I need and even started off the build by buying a Megasquirt PnP this morning. Very excited about this little project and I don't know what I am doing so that could spell trouble. I don't really care about making too much power, I just want to turbo it. Anywhere between 6-9 pounds of boost. I want the car to be reliable as much as it can be.

I know there are a bunch of cheapo turbo kits on ebay that might actually perform pretty well and I have nothing against that. I have decided to go with the CXracing kit. I am now trying to figure out my fuel system. Again, I am not looking to make too much power so I am not sure what will be overkill and what will be worth it. I don't want to cheap out completely but I also don't want to spend more than I need to.

Could someone please help me understand which fuel pump would be good to use (300lph inline pump?) and what size injectors would work best (24lb, 36lb, 60lb?). I am looking for something that is closer to the reliable side of things.

Please keep in mind I have zero experience with turbos and not too much experience in general. I might sound dumb but I am here to learn so please bear with me.

If there are other things you recommend I should look into, please feel free to let me know.

Thank you for your time and help.

[Kelso840]

If you plan on getting it dyno tuned when you're done building it (you should), reach out to the tuner and ask them if they have any preferences with injectors and fuel pumps. Hard to go wrong with Walbro 255 fuel pump though.

[Northern]

+1 to the above, if you have a tuner, ask them what they want.

Otherwise, there are 60lb Siemens Deka injectors that match the stock length and connector. They don't like the low pulsewidths that our engines run at, so some people have a rougher idle but this can be helped by bumping idle and running a bit richer at idle.

There are a bunch of off the shelf Bosch EV14s that will idle nicer, but a lot of them are shorter and require an injector hat/spacer and a connector adapter. Something like a Bosch 0280158123 (From a 997 911 Turbo) is ~58lb and has the old/correct EV1 connector. The tip is extended into the manifold more, but as far as I know, that doesn't cause issues. Price is basically comparable to the Deka 60s.

Note that the injector market is saturated with knockoffs, so buy from somewhere reputable and check over whatever you receive.

A Walbro/TI 255 would be great, but needs the bottom of the fuel pump hanger trimmed. Same warning with knockoffs.

[ForcedFirebird]

For 9lb of boost on a 60-ish mm turbo will put you about 280whp on pump fuel, and you won't need injectors much larger than 360cc. You can swap the head bolts for stud one-by-one and it will be dead reliable.

I tuned an m20 for a local that ended up going to college ~8hr drive from here. He was coming back almost every weekend and the only trouble he had was doing a drift event and popped the HG. Small t3 turbo from a Volvo, 324 TD manifold, ARP's, 12psi. The e30 it was in got wrecked by a couch falling off a truck heading S on I95, the motor went into a 2002 and ran in that car for some time - until it was sold. There's another e30 we built years ago here in FL, ended up in Cali, still rocking: LINK

[ADEN]

+1 to the above, if you have a tuner, ask them what they want.

Otherwise, there are 60lb Siemens Deka injectors that match the stock length and connector. They don't like the low pulsewidths that our engines run at, so some people have a rougher idle but this can be helped by bumping idle and running a bit richer at idle.

There are a bunch of off the shelf Bosch EV14s that will idle nicer, but a lot of them are shorter and require an injector hat/spacer and a connector adapter. Something like a Bosch 0280158123 (From a 997 911 Turbo) is ~58lb and has the old/correct EV1 connector. The tip is extended into the manifold more, but as far as I know, that doesn't cause issues. Price is basically comparable to the Deka 60s.

Note that the injector market is saturated with knockoffs, so buy from somewhere reputable and check over whatever you receive.

A Walbro/TI 255 would be great, but needs the bottom of the fuel pump hanger trimmed. Same warning with knockoffs.

What if i used stock b25 injectors (3.0 psi fuel regulator) and increased number of squirts to 6 with low boost like 6~9 psi?

Will i still be hitting injectors maximum duty cycle?

[soltani]

HI everyone!,

Thank you all for your replies, I appreciate the information. I have decided not to turbo the car and instead go with open trumpets for the time being due to cost even though its just going to be a few hundred dollar difference. With that being said, I have some new questions I would like to ask.

I am looking to replace my injectors with Bosch 27lb injectors but do not know what the correct part number is or where I can find them. Does anyone know this information?
I am also looking to buy a throttle cable with part number 35-41-1-162-482. This is from a 318i and required for the ITB build. I can't seem to find this anywhere in stock, any suggestions where I should be looking?

Thank you again for your help!