Louie928

Check your injector duty cycle. You can set the RPM where the LH goes from injecting once per revolution to once every other revolution with the ST. That will give you some extra time to keep the injectors open. If you are getting high injector duty cycle using the main map, the WOT map won't really help since the injectors can only be open for so long. I don't like the WOT map because it has no load input. If you are at 475rwhp, then you are beyond the load measuring capability of the standard MAF so you are basically just throwing fuel at it without regard to the air it is using.

dprantl

Yep, this is what I have learned from my time with the ST2. At WOT the EZK load is at 100% all the time and the injector duty cycle hits 100% at around 5k RPM. 30lb injectors and my standard MAF are not up to the task. Now, if I could just find my spare MAF so I can have John SuperMAF it...

Dan
'91 928GT S/C 475hp/460lb.ft

bd0nalds0n

He sells a SMAF adapter that goes between your existing MAF and the harness. No downtime necessary.

Louie928

Using the SuperMAF not only gets you more range for the LH load, but increases the load range for the EZ-K. If I could suggest..... Don't spend a lot of time tuning on the setup you have since it isn't adequate. Get a SMAF, or SMAF adapter, and swap out your 30 lb injectors for 42 lb injectors. Use stock fuel pressure. That will let you tune for good mixture and timing all across the entire load/RPM range. I put a TS SC (424 size) on a '91GT and tuned that. At 9 psi boost, it made 502 rwhp and great flat torque of 490 lb ft.

bd0nalds0n

Hi Louie,

Is the 424 the size Andy used?

Do the GT cams help or hinder forced induction? I think maybe there's more overlap which might not be advantageous?

What I'm trying to get at, of course, is whether 500 rwhp is replicable on my setup, which at first glance it would appear to be.

Louie928

I think Andy used 422 size normally. The 424 doesn't have to be turned quite as fast for the same boost. Presumably it would be more efficient, but I have no data to check one way or the other.

It appears that the GTs with SC do a little better than S4s with similar setups. However, almost none of the TS SC installations are the same and other things would enter in to cause differences. I remember I did a comparison between the conical K&N air intake Andy supplied mounted close in front of the MAF, and the flat stock 928 filter I put in front of the radiator. Andy's air intake lost 15hp compared to the 928 (paper) filter in the flat box in front of the radiator. I also port matched the SC mount/intake to the cylinder ports and chamfered the openings for better air flow. Hopefully, that helped.

dprantl

Oh sweet! I thought it had to be sent to be rewired.

Dan
'91 928GT S/C 475hp/460lb.ft

Louie928

John will convert your good MAF to a SuperMAF for $100 + $25 shipping. That means your MAF will be gone for about 20 days or more due to the transit time + time for him to work on it. Also, the MAF you send him may not be good and may have to be rebuilt first. If that is the situation, it would be $350 more.

John will supply a MAF to SuperMAF converter box for $225. The hangup on the MAF converter boxes is the difficulty in getting the MAF plugs and of course the time to make the things.

John Speake

Louie usually has a SMAF in stock. I can send him one by the end of this week. It will take about 1 week to him. As he says, I much prefer to modify a stock MAF rather than supply the seperate box. But I will supply them, it just takes a few days longer.

John Speake

Seperate SMAF box...

Tony

Yup, I'm using this also. If you have your WOT map set to all zeros, obviously it wont do any good. But you can go back into the map and add fuel at only the lower..lower to mid rpm ranges to utilize the switch more effectively.