another great Mark D review

[Mystikal]

I can explain it quite easily. With the stock injectors, the OBC consumption was not accurate. I manually calculate my mileage on every fillup, the OBC was always off.

When I went to 17.5lb, it became dead-on consistent, every time.

[Curtis325is]

Larger injectors actually make the OBC 100% accurate, ironically.

I have 17.5lb S50 injectors, and my OBC is now dead-on from calculated mileage (data taken from odo and actual fuel pumped in).

and how do you explain that? considering the gauges are programmed for stock injectors and the car has no way of knowing you are now using bigger ones.

What will happen is your car with use the O2 sensor to try to figure out the correct mixture, mean while your OBC and MPG gauges are working based on how often and how long the injectors are firing...but it thinks they are 14.5lb injectors...so it will be telling you that you are getting way better mileage then you really are. This is one reason why people who do injector swaps wrongly think they get way better mileage with bigger injectors, and why bigger injectors alone are not a good upgrade without proper tuning.

[dougsic]

Nice. I would do the injector upgrade if a device like this was available. I would have to send back my Mark D chip and get the one for bigger injectors though ;) hopefully he does exchanges. Any idea how much that device will cost?

There is a long thread about the correction device on the 24v forum.

I don't think Steve has set a price just yet awaiting final product costs, though he may have by now.

I traded him a stock s50 chip to install in his m50 and at that time (several months ago) he was expecting to bring this product to market for under $100.00.

After using it for a couple of weeks, I was so happy with it I offered to pay him $100.00 and let him keep the stock chip.

But then I'm obsessive about my cars and the wrong Econometer reading was truly driving me nuts.

[Mystikal]

Um, both? Mine happen to be from an S50.

[e30lyf]

^^^ 17.5lb S50 or M50 injectors?

[Mystikal]

Larger injectors actually make the OBC 100% accurate, ironically.

I have 17.5lb S50 injectors, and my OBC is now dead-on from calculated mileage (data taken from odo and actual fuel pumped in).

[Curtis325is]

Nice. I would do the injector upgrade if a device like this was available. I would have to send back my Mark D chip and get the one for bigger injectors though ;) hopefully he does exchanges. Any idea how much that device will cost?

[dougsic]

Changing the injectors screws up your mpg gauge and your OBC miles until empty and makes them useless.

Hoveringuy is making a device that corrects the Econometer and the OBC so that it works perfectly.

The installation is very easy - I have a prototype from him and it is awesome. After installing an s50, I was annoyed that the Econometer read 50 MPG and I missed having the "range" feature work on the OBC.

No longer!

His device can easily be calibrated to work with any engine/injector/induction setup. It is the size of a matchbook.

Last post I saw he'd sent the circuit board overseas to have a batch made. Should be done by now.

I absolutely love mine and it works perfectly.

[Curtis325is]

I have stock injectors with a Mark D chip...but I can't stop flooring the car to test the gas mileage ;)

Mark D'Sylva sells chips for stock injectors, 17# and 19# injectors. The bigger injectors allow for future upgrades that may require more fuel. Changing the injectors screws up your mpg gauge and your OBC miles until empty and makes them useless. I don't think you need bigger injectors until you start getting over 200hp (ie stroker, head/intake work, forced induction).

[///M42 sport]

any of you guys have stock injectors? and also will mileage improve?

[ZM Blue Devil]

+1 as well, it woke up the engine! Love it best mod ever.

[kishg]

+10 i have the markd chip with #19 injectors and the result is very nice.

[delatlanta1281]

You can, but it's easier to remove the vc.
I love my Markd chip btw.

[Wishno87]

How hard was it to do the injectors? What's the benefit of them?

i think they just squirt more fuel, you can probably take them off without removing the intake manifold

[Pac0]

How hard was it to do the injectors? What's the benefit of them?