Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Last ST200 UIM anywhere and How to put SVT LIM on 95?

That's right, I knew I wasn't crazy!

The SVT ones are slightly curved, perhaps because the ports are so much bigger.

Hey Matt, can you snap a pic of the linkage? I want to see the difference between that and the 95.

-Lance

I remember someone said that the runners in the LIM tapers down.

Mine has a little more metal missing from the ports Gotta love a drum sander

Going on the wiht the ported 3L upper and tb also

Thanks Chris for the Dyno plots! Incidentally NOW I can find your plots in the archives â?? I swear the search function doesnâ??t always work reliably.

Did some calculations on injector sizing. I used the calculator and formulas found here:
RC Enginering injector math.

As a test I put in the stock 1995 2.5L Numbers

Horsepower, SAE net = 170
Brake Specific Fuel Consumption = 0.45 lbs/hour/BHP (many assumptions here)
Fuel pressure = 39 psi
Injector duty cycle = 0.8 (industry standard).
Calculated required Injector static flow rate = 16.83 lbs/hr (ignoring any differences between SAE net and BHP)

This is dead-on to what I would expect given that Ford chose to install 17 lbs/hr
Injectors.

Rearranging the equations a little and assuming an extreme of 0.95 duty cycle on stock 17 lbs/hr Injectors gives 205 BHP.
With ATX, assuming 25% parasitic drive loss, this gives a maximum of about 154 HP at the front wheels.
With MTX, assuming 15% parasitic drive loss, this gives a maximum of about 174 HP at the front wheels.

Chris Wongâ??s dyno plot (17# injectors) shows a max of 167.81 HP at front wheels (looks like a fun ride!). Chris estimated about 205 BHP. It doesnâ??t seem to me as if the engine was suffering significant fuel limitations though Chris did post that it was running lean. Would need correlated A/F ratio info to be sureâ?¦

What does this all mean? Isnâ??t a 0.95 injector duty cycle unrealistic? If I planned to drive my car competitively this would make an excellent argument for increasing the injector size. However, I am realistically only very rarely going to push my engine to maximum power output on a public street! For the short durations this is likely to occur, the above calculations give me a level of confidence that I will not be running hopelessly lean. My engine mod plans are for improvements in everyday driving conditions, primarily increased torque at all engine speeds. I plan to stick with my 17# injectors for now. Am I correct in this thinking?

P.S. Earlier I posted that I was hoping for 180 FWHP. Sheer Bravado!! I will be thrilled to see peformance at the level of Chris's 95 SE!

Thanks Matt for the ST200 throttle bore picture. So the throttle bore DOES taper down. Bad news for me. It looks like it will be more trouble to duplicate an ST200 LIM starting with a stock 95 casting than I thought. Straight bore is easy; a more complex shape is not worth the trouble. Wish Iâ??d had an ST200 LIM to study before I made all that noise earlier! Maybe Iâ??ll just clean my 95 LIM up with an ST200 UIM port match and optimize the plate screws (still a lot of work). What do you think Alex?

Just for general interest, the "Last ST200 UIM anywhere" in thread title actually came from Chris Wong at CTA Motorsports. Hey Chris, my check show up yet! It was cool to se you posting in this thread.

Regards, Jim

Check your emails, Jim. Your UIM shipped out today.