Aftermarket ECU setup questions (Haltech + 205gti)

DjB8V

Active member
Fellow Frogger
Joined
Nov 7, 2010
Messages
936
Location
8V'ville
I've bought a new Haltech Elite 550 for my 8 valve and I'm stumped on a few things.

Basics first. High compression 8v, individual throttle bodies (Jenvey Weber style items), I have a new unterminated loom also from Haltech. Intended use, hot road car.

1. O2 sensor. It's looking like I'll need to run a narrowband O2 sensor based on the ECU I have. It can be expanded to run a wideband one, but it'll come at a $$ cost. Has anyone ran a narrowband sensor in a similar setup? I understand that the afr band reading his quite narrow. Will this have any negative effects for road use.

2. The ECU has an inbuilt MAP sensor. Regardless of an inbuilt or external MAP sensor, what's the best method to get an accurate manifold pressure signal? I bought a manifold pressure distribution block, but until I'm 100% sure that drilling and tapping fittings into each runner of my inlet manifold is the way to go, I want to check with someone who knows better than me.

3. Using a 60-2 flywheel, will I need a cam sensor?

Thanks in advance legends!


Chris
 
1. O2 Sensor - using a narrow band is fine. Just select it as an option in the drop-down list. You still need this in order to avoid damage to the cat and get decent fuel economy on cruise. You can vary the percentage around 14.7:1, but typically you should be able to get it down to +/- 5%.

2. MAP - drill and tap M6x1 into the bottom of each runner, approx 50mm from the manifold face.

3. 60-2 - No, you only need the cam sensor if you want sequential injection or direct fire ignition. With just the flywheel sensor, you would select Multipoint fuel and either distributor OR wasted spark (depending on your setup).
 
1. You can use a narrow band O2 sensor to operate in closed-loop mode, however it will be of no use to you during tuning.
2a. Neither internal nor external show any performance benefits over the other. The mass of the volume of air between the manifold and the sensor is too low to have any inertial effect.
2b. You might not get the motor to run very well using MAP if you have large throttle bodies and short runners. You might be better off considering tuning for alpha-N.
3. Yes, if you want to run sequential ignition/injection. No, if you're happy to run batch injection and wasted spark ignition (or are retaining the distributor).
 
Last edited:
Cam sensor only needed for sequential. I have a Jenvey manifold with drilled and tapped fittings also distribution block, can take photos. Jenveys are for sale by the way. I've never bothered with an O2 sensor.
 
Champs. Thanks a bunch.

Graham, if you could post some pictures that would be great.

Thanks again!


Chris
 
I map the fuel via TPS and the ignition via MAP. It works very well.

You can use the narrowband for light load tuning by watching the injection time. As the mixture approaches 14.7:1, you will see the injection time start to fluctuate by itself as the ECU works to maintain 14.7:1 +/- 5%, if that's what you set as the range for closed loop.
 
Here is my vacuum manifold. Four hoses in, two hoses out. One hose goes to the ECU, the other to the fuel regulator. The third barb was for the brakes, before I changed to a pedal box.
 

Attachments

  • IMG_0167.jpg
    IMG_0167.jpg
    157.8 KB · Views: 205
  • IMG_0168.jpg
    IMG_0168.jpg
    106 KB · Views: 215
This is the vacuum manifold I have.
 

Attachments

  • 20210103_211928.jpg
    20210103_211928.jpg
    75.1 KB · Views: 181
Cam sensor only needed for sequential. I have a Jenvey manifold with drilled and tapped fittings also distribution block, can take photos. Jenveys are for sale by the way. I've never bothered with an O2 sensor.
What jenveys have you got for sale Graham?
 
Photo of my Jenveys. 4 to 1 EFI Hardware vacuum combiner. I took vacuum for the brakes off two inlet tracts. 45 mm. I would want $1000 for the set including Peugeot XU 16valve manifold and Pipercross foam filter set up. Took the photo in a hurry can send without the other items, from different angles and with the hoses properly removed plus in higher def to an email address.
 

Attachments

  • Jenveys.jpg
    Jenveys.jpg
    862 KB · Views: 249
If anybody needs the manifold but already has throttle bodies, I may be interested in the throttle bodies.
 
Cheap enough to buy it all? Probably spent close to that that on the injectors, 4 to 1 and Pipercross Filter
 
$1000 is cheap for Graham's setup. What engine could 45's be too big for?
 
Top