DRZ400S Fuel Injection Project

[moto-scoot]

The last few months I have working on fuel injection and ignition control for my DRZ. I have setup fuel injection on a few other cars before with OEM components and with MegaSquirt with good success. MegaSquirt is an open source, DIY injection controller. I have toyed at the idea of EFI on the DRZ for a few years. I am not sure if it is worth the effort since I have had the FCR39 tuned fairly nicely, and a non-oem efi could possibly have reliability problems and fuel pump, ecu and sensors weight around 5 lbs more than a simple carburetor.

Last night I had it fired up, and tuned in some of the low RPM/low load areas of the map and roughed in some of the other areas of the map.

Here are some details of the setup:

40mm throttle body from a Honda TRX680 quad, I have looked ant many different motorcycle/ATV throttle bodies in this one looks like it will suit the application the best.

400cc 12-hole denso hi-impedance injector

The throttle body has in integrated throttle position sensor, air temp. probe on the air filter side of the throttle blade, 2-bar m.a.p. sensor, and a stepper motor idle air control.

The Suzuki Hayabuss intake rubbers are a perfect match for the cylinder intake spigot and the throttle body. I used a stock DRZ400S air box boot to connect to the air filter side of the throttle body.

Suzuki Hayabusa external fuel pump with an integrated fuel pressure regulator and fuel filter, mounted were the coolant tank reservoir was.

MegaSquirt based controller, running the extra code in a sealed enclosed with a sealed connector and extra circuitry to pickup the stock VR sensor ignition pickup signal, the components will be potted to protect them from vibration once everything is tested.

The map is setup Alpha-N hybrid, so the injection length is determined by the RPMs, throttle blade opening, manifold pressure, along with minor fuel trim corrections from the air and coolant temp sensors and the barometric pressure

a bosch 14mm coolant sensor that fits in place of the fan temp switch in the radiator, the fan will be controlled by the efi computer (on at 210 F, off at 207 F).

The fuel tank has a 3/8" brass bulk head fitting the for fuel return. I am using a hi-flow pingle tap for the fuel feed to the pump.

The fuel injection wiring harness is made with sealed deutsch connectors and high temp GLX automotive grade wiring.

For tuning I have a techedge wideband controller with the wideband O2 sensor in the mid pipe.

I few problems I have run into:

The ignition pulse from the flywheel gives two trigger pulses per revolution, one before TDC and one at TDC. I will probably have to shave one of the two lobes off the flywheel when I get to setting up the ignition control. For now I have set the fuel injection controller to two cylinders, with odd fire to get a correct RPM reading. I am still using the stock CDI ignition box. MegaSquirt still has problems with the two triggers at cranking.

The stock 180 watt stator seems to run every thing ok, it is charging the battery when the rpms are over 2200.

Here is what everything draws:

Stock headlamp: 55w

LED Tail/brake light: 3w

Fuel pump: 57w

Speedo and idiot lights: may be 3w

Turn signals (rarely used) 20w

Injector (worst case, 100% open) 11w

EFI controller: 5w

Cooling fan: 20w

So the worst case power draw would be 150-160 watts

I'll post some photos of the setup when I get a chance.

So far with an hour of tuning, it idles better than any carbureted DRZ and the throttle response is very crisp from idle to WOT with no load. Once I get everything fairly dialed in, I’ll fine tune the fuel map on a dyno.

Does any one have the ignition curve for the stock CDI? I know that it idles around 7 degrees, and it looks like all the advance is in around 4500 rpms.

Jeff Corsaro

[TX-SANDMAN]

Sweet set up!

[Sixer]

Sweet set up!

+1

Keep us updated and we'd love to see some pictures. I can host them if you need.

?

[UncleBob]

if you are doing fuel-only, simply reference the primary coil wire. That will give you near-TDC reference. no reason to get all fancy with the twin cylinder odd fire setup.

if it were me, and you wanted to incorperate the ignition with MS, I'd shave off one of the tabs (they are not the same length BTW) and add at least 2 more signals....ie, make at least a 4-1 trigger wheel

You can see the stock timing, if you go to dynatek and look up the installation instructions for the ignition programmer on the LTZ400. I'm told LTZ and DRZ use the same ignition curve.

why the alphaN hybrid? Why not full speed density?

[drzsporter]

Impressive!?

[Wayward Son]

pretty cool.

[Wrfrk]

Waaaaaay over my head, and likely the heads of most of us, but that is awsome. Why wait for Suzuki if you can DIY!

[ExcDan]

If you remove one of the crank teeth, the ecu might not sync up - it has to know which cylinder is which to synchronise the injection with that cylinder

[socaldrz400s]

Thats about what I was starting but lost interest. If youve got a welder and the time, get a Garrett GT12 Turbo. Double stack the "S" base gasket. Use the Aux output on the MS for a PWM-Boost controller and try to set the boost at 7PSI (.5bar)

Hey, Someone has to do it and im selling my DRZ next week..

[UncleBob]

well, you don't HAVE to EFI a bike to get a reliable turbo system

When you add a scavenge pump to all the stuff he already has, I wonder at what RPM the charging system breaks even....

[Ground Loop]

Hell of a first-post, Jeff!

This sounds well-researched and most excellent.

After wrenching jets in and out of my carb for a month and staring at air/fuel plots -- I'm never buying another carb'd bike. I've been thinking lustful thoughts about a Megasquirt.

Your post confirmed that conversion to EFI is out of my league, but I'd be an enthusiastic first customer for anyone that wanted to sell a tested DIY kit.

Thanks for posting the details! Good stuff.

[NMdesertRacer]

Two thumbs up ! We need Pictures ASAP!

[12Johnny]

Impressive first post!!!!!! ? :p

[DougJ]

Impressive first post!!!!!! ? :p

+1

Very interesting, please keep us updated!

[jksgvb]

Does the fuel pump really take 57W? Continuously? That figure seems wayyy high.

[ZipFire]

I started a link on the KTM forum which mushroomed into a mega debate between EFI and carb for dirtbikes: https://www.thumpertalk.com/forum/showthread.php?t=463180

[moto-scoot]

Eventually I want to control the ignition, so I was not going to bother with a trigger from the stock ignition coil. I probably will end up grinding the long tooth off the flywheel and possibly turn the flywheel into a multi-tooth wheel with a welder, grinder and lathe.

Thanks for the tip on the ignition curve from dynatek. A riding buddy of mine let dynatek barrow his DRZ recently for them to test there ignition system on his bike.

I think I will build a fuel table for both Alpha-N and speed density and see what works out best. I do have a feeling a speed density based table will work better, especially when lugging the motor along on the trail.

if you are doing fuel-only, simply reference the primary coil wire. That will give you near-TDC reference. no reason to get all fancy with the twin cylinder odd fire setup.

if it were me, and you wanted to incorperate the ignition with MS, I'd shave off one of the tabs (they are not the same length BTW) and add at least 2 more signals....ie, make at least a 4-1 trigger wheel

You can see the stock timing, if you go to dynatek and look up the installation instructions for the ignition programmer on the LTZ400. I'm told LTZ and DRZ use the same ignition curve.

why the alphaN hybrid? Why not full speed density?

[moto-scoot]

That's what I measured, when I powered the pump with 14 volts. It uses less current at 11.5 volts, and defiantly has enough pressure to feed a single injector in my application. It seems like most of the EFI pumps draw 50-100 watts, except for a tiny 15 watt Synerjet pump used on an EFI Aprilia 50cc bike. I don't think that pump will have the volume to feed a 400cc engine.

Does the fuel pump really take 57W? Continuously? That figure seems wayyy high.

[vfr_nz]

Hi

Not sure whether the US gets a LT-R450 Quad. It has a single cylinder fuel injection system. Makes plenty of power and is really drivable. Rumour has it that this motor may appear in some form of dirt/sm bike in the future.

Wayne

In New Zealand

[moto-scoot]

The FCR carb on the DRZ is a PITA on the DRZ, I can't count how many times I have had the rear sub frame swung up to play with the carb. On my old 98' WR400, it was much easier to access the jets on the FCR carb.

You don't want to know how much $$$ I have into this project all ready. I probably have about $175 in the sealed connectors. If anyone else want's to tackle a DIY efi on a DRZ, I would be happy to share settings/fuel tables once I have them dialed in.

Hell of a first-post, Jeff!

This sounds well-researched and most excellent.

After wrenching jets in and out of my carb for a month and staring at air/fuel plots -- I'm never buying another carb'd bike. I've been thinking lustful thoughts about a Megasquirt.

Your post confirmed that conversion to EFI is out of my league, but I'd be an enthusiastic first customer for anyone that wanted to sell a tested DIY kit.

Thanks for posting the details! Good stuff.