M42 turbo dyno results

[wazzu70]

I don't think you need to go to a smaller turbo at all. The GT3071 is a good size for what you have. What I would try is experimenting with a splitpulse manifold and housing as you can get those now for the GT30s in a split T3. This would give much better response and allow you to run a larger turbo so you do not choke off flow up top where you need it in a race car. Also, you can turn up the wick on boost.

Do you have it set where you do because you noticed knocking or just because? Just wondering if you stopped where you did for a reason or just out of nerves :)

As you know I am working on my project, and I will be using a splitpulse manifold and a holset turbo. I also intend to push the limits on my stock bottom end as I dont have to worry about DNF'ing a race. Will be interesting to see what I can do and compare setups.

If you need a splitpulse manifold you can purchase one from Bonje in Sweden who had the 600+hp M42 motor. He has a jig for the manifolds and can sell you one for a resonable price. His English is also very good so you dont have to learn any Svensk.

I wouldn't run smaller than a GT30 on that engine though. Focus on getting more out of the one you have. Mild head porting and cams can really increase flow/power while decreasing the pressure in the manifold.

Just my thoughts, but you can wait for me to be the gineua pig if you want and have time to wait :)


The M42 does have squirters and sodium filled valves. I have a few pictures of the guts of my motor on e30t in the project garage if you want to see.

[SpoolnDaapex]

Alot more comes into the equation than whether the pistons are cast or forged obviously. But having said that I am planning to run up a standard engine to get a base tune to run the new engine in on.

Your probably right. Im no engineer and just graze in turbo stuff.

I have heard the m42 has piston oil squirters and sodium filled valves which is obviously great for boost.

[e30guydownunder]

You need anywhere up to 40% more volume at WOT to run E85. My injectors have a fair amount of headroom but at the time the price difference was bugger all. 20% is the general number thrown around for efficiency. But generally you will need between 20-35% more fuel over a similar gasoline map.

A local turbo M42 maxed out some 68lbs injectors at 230kW.

[einstein57]

According to everything i've read e85 uses about a 20% higher fuel consumption rate then standard gasoline.

[e30pq]

Regarding the injectors, does E85 require more injector volume?

[e30guydownunder]

And Subaru guys have been running 17-20psi on cast pistons for many years now.

Alot more comes into the equation than whether the pistons are cast or forged obviously. But having said that I am planning to run up a standard engine to get a base tune to run the new engine in on.

Only reason I went forged in the end was because I wanted new rings anyway, Forgies aren't that much really in the scheme of things.

Wow. I like what you're doing.

We are actually in the process of building a second M42 powered car. This time it will be an E36. We haven't fully figured out what turbo we are going to run but we are going to follow a similar formula of with 10:1 CR and smaller turbo.

Thanks, as you have probably noticed on a few forums, my project has been a long time coming. Finally been busy spending large amounts of money and about to get cracking on it all! Trying to do it on a relatively tight budget, but spending money on the things it is needed.

Have got a DTA S60 to run the show, 1000cc Injector Dynamics and a AIMSports Dash and Logger setup. The E85 has only just become available on the pump here so I pulled the trigger on the high CR pistons.

[e30pq]

I've got some JE pistons coming. 10:1, will be doing O-rings and changing up to M12 Head Bolts. Apart from that, homebrew turbo mani, 3" exhaust. Standard E36 Intake for the meantime. Will be running E85 fuel and have a GT2560R. 0.64 A/R. This will be well out of efficiency by 20psi.

I'm hoping to get over 150kW (200hp) out of it and based on a few projects done over here may head toward 180kW (240).

It should be nice and responsive with the high CR and small turbo. I may well end up going bigger and while there are several people over here running GT3076's, I will still tend to the smaller frame turbos and have a 2860 or 2871 in mind. Just going to suck it and see what happens with the 2560.

Wow. I like what you're doing.

We are actually in the process of building a second M42 powered car. This time it will be an E36. We haven't fully figured out what turbo we are going to run but we are going to follow a similar formula of with 10:1 CR and smaller turbo.

[SpoolnDaapex]

Considering that Formula one is going back to turboed four bangers, I suspect that we will see a new trend... Even VAC is working on a turbo kit for the venerable S14.

Also, what we've seen on the forums is people running stock volvo turbos at 10psi with homemade setups making barely close to 200whp. I think people are turned off by that when you can swap in a m/s50 and make the same power or more, without the hassle of forced induction.

But i think people are starting to realize the m42 can take much more than previously thought. After all we've seen cast m20 pistons hold 20psi for years.

And Subaru guys have been running 17-20psi on cast pistons for many years now.

[e30guydownunder]

I've got some JE pistons coming. 10:1, will be doing O-rings and changing up to M12 Head Bolts. Apart from that, homebrew turbo mani, 3" exhaust. Standard E36 Intake for the meantime. Will be running E85 fuel and have a GT2560R. 0.64 A/R. This will be well out of efficiency by 20psi.

I'm hoping to get over 150kW (200hp) out of it and based on a few projects done over here may head toward 180kW (240).

It should be nice and responsive with the high CR and small turbo. I may well end up going bigger and while there are several people over here running GT3076's, I will still tend to the smaller frame turbos and have a 2860 or 2871 in mind. Just going to suck it and see what happens with the 2560.

[e30pq]

I will certainly be able to provide a dyno graph comparing stock M42 and boosted :)

The numbers from my little turbo won't be that impressive though

What kind of work are you doing to your engiine?

[Massive Lee]

I have seen kitchen assembled turbo M10s making superb torque.

[e30guydownunder]

It would be great to compare the torque curves of a stockie vs this turbo. ;-) The turbo motor will probably double the value at mid rpm.

I will certainly be able to provide a dyno graph comparing stock M42 and boosted :)

The numbers from my little turbo won't be that impressive though

[Massive Lee]

Never understood why they never caught on. Turbo motors are more efficient. And you don't need to have a 500hp motor in a daily driver either. The main gain is not necessarely the power, but the torque gain, which is great for a small responsive turbo that kicks in early. Small=no lag.

[rThor432]

^^Thats a good trend to return to. I hope the automakers catch on.

[Massive Lee]

Considering that Formula one is going back to turboed four bangers, I suspect that we will see a new trend... Even VAC is working on a turbo kit for the venerable S14.