HFS-6 and direct port on a big turbo BMW 6 cylinder?

[5mall5nail5]

Hello all - I am going to be purchasing an HFS-6 soon. I have a BMW 2.8L 24v (bored .025 over) with a 76mm turbo and a fully custom exhaust and intake manifold. The car has a 28x23x4" front mount intercooler, 3" charge piping with adel wiggins fasteners, a CNC and flowed intake manifold, T4 PT76GTS turbo, and Injector Dynamics 1000cc fuel injectors running a DTA S80 Pro ECU (UK guys may recognize that).

I am interested in running direct port methanol/water injection ONLY if it is beneficial. I have a few concerns:

1) Will the system pulse properly given the additional volume a "distribution manifold"? I would think the volume of fluid would be increased and since there's no mechanical injection valve at each runner, wouldn't it dampen the pulses and ultimately change the systems effectiveness?

2) Would the engine draw the methanol/water from the "distribution manifold" after injection, under engine braking (vacuum) and ultimately hinder the system from shutting off immediately during decel?

3) What size injector nozzles would be ideal? I guess my long term power goal for this car is 850+ rwhp, running the turbo over 30 - 35 psi. But, I don't want nozzles so large that I can't adequately control the methanol system at say 20 - 25 psi on the street.

Thanks guys - any help is appreciated!

Here is a photo of the intake manifold and the car:





Thanks again

[Richard L]

My reply in green...

Originally Posted by 5mall5nail5

Hello all - I am going to be purchasing an HFS-6 soon. I have a BMW 2.8L 24v (bored .025 over) with a 76mm turbo and a fully custom exhaust and intake manifold. The car has a 28x23x4" front mount intercooler, 3" charge piping with adel wiggins fasteners, a CNC and flowed intake manifold, T4 PT76GTS turbo, and Injector Dynamics 1000cc fuel injectors running a DTA S80 Pro ECU (UK guys may recognize that).

Your build is outstanding especially the welded manifold.


I am interested in running direct port methanol/water injection ONLY if it is beneficial. I have a few concerns:

1) Will the system pulse properly given the additional volume a "distribution manifold"? I would think the volume of fluid would be increased and since there's no mechanical injection valve at each runner, wouldn't it dampen the pulses and ultimately change the systems effectiveness?

Ideally, if you can place the nozzle as far away as possible from the manifold, there is good chance of good distribution amongst the cylinder due to early mixing and droplet reduction along the inlet tract as they eveporate.

2) Would the engine draw the methanol/water from the "distribution manifold" after injection, under engine braking (vacuum) and ultimately hinder the system from shutting off immediately during decel?

There is always a chance of the water lingering along the cylinder wall when the throttle is snapped shut. On your picture I cannot see where the throttle plate/plates is/are. Asssuming most BMW uses individual throttle plate on each runner, there are little vacuum present in the manifold to cause any run-on problems. Anywaym even there vacuum present, HFS-36 shuts off pretty positively. The only fluid that is wet the manifold wall are those left in the hose or inside the fluid distribution manifold.

3) What size injector nozzles would be ideal? I guess my long term power goal for this car is 850+ rwhp, running the turbo over 30 - 35 psi. But, I don't want nozzles so large that I can't adequately control the methanol system at say 20 - 25 psi on the street.

M50:W50 mix works well between 15-20% ratio to fuel. Your maximum fuel flow is 6000cc/min. So your ideal target fluid flow is between 900-1200/min. You will need to plumb in 2x 1mm nozzles (~1100cc/min) for your application.

Richard




Thanks guys - any help is appreciated!

Here is a photo of the intake manifold and the car:





Thanks again

[5mall5nail5]

Thanks Richard!

This car in particular has a single throttle plate and pulls decent vacuum.

Would you recommend single point injection ahead of the throttle plate vs doing direct port?

[Pit Viper]

I've had slightly better performance doing direct port, but I couldn't give you a really good reason why. And it's a slight increase. However, with my current car (6-cylinder twin-turbo Audi), I think I'm going to need to add in a 7th nozzle prior to the IAT sensor, as the car adjusts timing based on that, as well as knock detection.

I can't tell you how jealous your engine bay makes me, by the way.

[20vturbo]

that's a crazy build