M20 Turbo Setup Questions

[beggs]

I was thinking of slapping on a turbo onto my 1987 325iS. I'm getting most of my parts from VAC motorsports. Right now my car is bone stock with the exception of lowering springs. My power goals are 350hp this winter and in the summer going up to 450 or maybe 500. Parts List:

VAC - M20 'Pro Series' Turbo Build Kit- comes with MLS head gasket plus head studs
Kamotors Canyon Crusher kit
Miller - M20, ProStreet Induction Kit
Bosch - Universal High Volume In Tank Fuel Pump ' 040
VAC Billet BMW Rocker Arm Set (M20)
BMW M20 Turbo Camshaft - Mild Grind

Some of the questions I had were.. Would you recommend getting a forged crank? or at least a new em one because the motor has 174k miles on it.
Does the head need to be ringed and the water channels welded? Not sure on this because the turbo it is coming with a MLS hg.
And since the Kamotors Kit will need me to remove the oil cooler, should i just pick up a universal one by Mishimoto? Plus, if you recommend anything else please comment! Anything Helps! Thanks.

[ak-]

Whoa, billet rockers? If you're going to be dropping this kind of coin on your build (seeing as you're able to), I recommend doing everything to the best of your ability and right from the beginning to achieve your goals.

First and foremost, I would invest in a better turbo and exhaust manifold. You're investing in $2000 rockers, but a $200 thin manifold made in China. Look into one that can be custom made for your needs. Why not go twin-scroll while you're at it?

Second, I would up the liter of the build considering the caliber. Going from a 2.5 to a 2.7 made a huge TQ difference for me and makes me wish I went 2.9/3.0 from the start.

Next, I would O-ring the block rather than MLS it (we O-ring the iron block rather than the aluminum head on these motors), as an MLS can still blow and are a little notorious for leaking (especially on M20's). You're going to have a strong bottom end so I would 100% O-ring it instead - you won't be bending a rod at that power when finely tuned.

A forged crank would be icing on the cake, but there is no need in my opinion.
Definitely weld the water channels shut in the head and get it rebuilt - Bimmerheads on the forum do great proven work.

Where you live, you probably wont need an oil cooler to be honest unless you plan on thrashing your car for minutes on end going uphill, but if you're set on one I would go with a proven brand like Fluidyne with AN fittings. I would actually use AN fittings on everything rather than clamps like there are on Kameron's install pictures - they will leak, no matter what, they will all eventually leak.

[beggs]

For a stroker kit, who is a good manufacturer? I'm looking at the Ireland Engineering 3.0 Stroker kit and they seem like a pretty credible manufacterer. If I got that, I would just need connecting rods...
And for as for oringing the head, I would just use the stock hg for that?
For the turbo I was thinking of asking Kameron to not include the 6262 and buy a GTX3067R.
Thanks for the quick reply!

[ak-]

I think IE would be an okay choice.
GTX3067R is a great choice for the bigger liter motor. The 6262 is cool, but isn't as fun on the street which I imagine will be most of your driving.
As soon as you get on boost, you're already doing well over the speed limit which doesn't sound like much fun.

You would use the stock HG for the O-ring'd block yes (not head :p)
Get it straight from BMW/dealership - don't use whatever it is vendors sell, it is not the same quality.

[beggs]

I think IE would be an okay choice.

Any other company you would recommend?

[beggs]

If I sourced my own stoker kit it would be cheaper correct? I was looking at some S52 crank and rods and these VAC motorsports pistons

https://store.vacmotorsports.com/mobile/cp-carrillo-bmw-m20-forged-piston-set-for-896mm-stroker-crank-p2921.aspx

Does this look like a good setup?

[Clemons]

i am planning a very similar build by using the i.e. 2.9 kit. i tried to look up the GTX3067R on an m20 and i couldn't find anything. I have a ie upgraded rockers and valve springs, 272 cam, valves were redone but the water channels were not welded. pt6262 seems to pick up a lot higher then i would like. in what power range do you think that setup will perform? what size hot side etc? I have never had to choose a turbo before and i appreciate everyones help. I do not want the car to feel peaky, drivability is very important to me even though it is not my dd.

[ocCube]

Hi..
i didnt want to open a new thread, so i'll ask here...


I'm planning on a m2025 turbo build and i'd like to use the MHI TD04HL-16T 7cm.
It comes from a 2002 Volvo V70 T5 2,3l with 250hp stock.

I know it sounds a bit small, but i did some calc and it should just top out at 300hp with 430cfm at 15 PSI with great response and spool.

So..do you think it'll work out?

regards from Germany!



map:

[cleanasse30]

Hi..
i didnt want to open a new thread, so i'll ask here...


I'm planning on a m2025 turbo build and i'd like to use the MHI TD04HL-16T 7cm.
It comes from a 2002 Volvo V70 T5 2,3l with 250hp stock.

I know it sounds a bit small, but i did some calc and it should just top out at 300hp with 430cfm at 15 PSI with great response and spool.

So..do you think it'll work out?

regards from Germany!



map: [ATTACH]105608[/ATTACH]

Will it work out? Sure. Will it perform how you want it to? depends

With a hot side as small as that one its going to spool very early and choke on the top end. That is how most affordable factory turbo cars, such as the volvo this turbo comes from, are setup up. WRX, Focus ST, etc use smaller turbos so they are fun to drive on the street where most of your time is spent between 2k and 4k rpm. But if you plan to use your car on a track where you spend most of your time in the upper part of the power band a larger turbo is usually better.

Personally I would get a larger turbo than a TD04.

[ocCube]

Okay, it is as i expected.
This is my first turbo projekt, so i planned to use this turbo first to get experience with MS and get the car running good. I planned to upgrade the turbo later ( TD06-20G).

Do you think the 16t can hold 7-10 psi to redline?
What do you exactly mean with choking?
I don't want to risk the engine because of high backpressure..

The main reason i bought the it, is because i can also use it as an upgrade for my DD Volvo V70 2,4t.

Thanks for your help man, i did all the calculations and stuff but i don't have any experience yet.

[cleanasse30]

Okay, it is as i expected.
This is my first turbo projekt, so i planned to use this turbo first to get experience with MS and get the car running good. I planned to upgrade the turbo later ( TD06-20G).

Do you think the 16t can hold 7-10 psi to redline?
What do you exactly mean with choking?
I don't want to risk the engine because of high backpressure..

The main reason i bought the it, is because i can also use it as an upgrade for my DD Volvo V70 2,4t.

Thanks for your help man, i did all the calculations and stuff but i don't have any experience yet.

It should be able to hold pressure just fine, that isn't the problem. Choking might not have been the best choice of words, but the turbo probably wont be able to flow enough air efficiently to continue increasing power in the top end of the RPM band. It will likely feel fast while accelerating up to 4-5k rpm, but once you hit that point it will feel like the car isn't accelerating as fast as it was lower in the powerband.

Think about it like this. A turbo is a device that pushes air into a tube (intercooler pipes) and subsequently into the cylinder in the engine. In order to fill that volume the turbo compressor wheel spins to push air into the intercooler pipes. A smaller turbo has to spin faster to create the same amount of pressure. What happens when things spin faster? Heat. The faster the compressor wheel spins, the more the air being compressed is agitated. On a particle level this causes friction between molecules and results in hotter air and hotter air intake temps, which means you can't run as much timing which leads to less power (generally).

Hope that helps.

[Dirty3024]

Honestly just my opinion. The KA motors kit is probably one of the nicest kits you will find. I can honestly say unless your a fabractor and you wanna do it right your gonna spend close to 3 to 5k. I pieced my kit together and I'm close to 5k. Starting to think I should have just gone with the KA kit from the start. I spent about 2 months gathering as much info as i could before I started buying everything.

Shit adds up quick brother still don't know how people turbo there cars for 2k