Fuel management/Tuning upgrade suggestions

[40BelowSummer]

So I have a supercharged SHO with the following:

- 36lb fuel injectors
- Mark VIII 80mm MAF
- SS LPM (running pretty rich)

The car last dynoed 419whp with the Vortech S-Trim.

I have a TwEECer RT on the way to replace the LPM. Ive got a spare set of fuel rails ready for the machine shop.

Think some 44lb injectors and a lightning 90mm MAF would be adequate replacements for the existing setup?

Just looking for some input before I purchase.

Thanks! :wave:

EDIT: Also, can I send my LPM to TwEECer for a base tune or is there a better way to go about that?

 

[Super Matty P]

If you've got 36# injectors and you're running horribly rich why are you wanting to get larger 44# injectors?


Do the MAF upgrade first...get a GREAT tune and see if you need more fuel after that.

p.s. Great numbers!!

 

[40BelowSummer]

It was programmed to run rich. Im thinking Im pretty close to maxing the injectors duty cycle. Using bigger fuel injectors allows you to spray the same amount of fuel as a smaller injector, but at a lower duty cycle.

 

[AutoSHO]

At 420 whp I'll put money on those injectors being wide open past around 5500 rpm... If not sooner. That's very small for that much power. Can you scan and post the dyno sheet?

Do you plan on making more than that much power? If not, you can stick with the lightning 80mm MAF, which keeps you from having to modify the piping at all. It is the same body as the Lincoln, with a different sensor package on top that has a much higher airflow capacity.

 

[40BelowSummer]

Do you plan on making more than that much power? If not, you can stick with the lightning 80mm MAF, which keeps you from having to modify the piping at all. It is the same body as the Lincoln, with a different sensor package on top that has a much higher airflow capacity.

The car has no intake charge cooling yet. Water injection very soon (at the least). Who knows maybe a 15psi pulley in the future after the tuning gets nailed and I become comfortable with the TwEECer. So I would say its going to see a bit more power.

Im just trying to decide between the 80mm and the 90mm. And also if the 44lb'ers will be sufficient.

Its going to the dyno after I get the TwEECer.

 

[yamahaSHO]

I agree with Chris, the 36# injectors are way too small for that kind of power. With the TwEECer, you'll be able to see how much work those injectors are actually doing. 44 or 48# injectors would suit you better.

Don't bother using the LPM program as a base tune. The best thing you can do is get smart about what needs to be done and modify the stock program. The 80mm MAF from the Lightning will probably be all you need, and like Chris said, no modification is required aside from a new harness connector which can be had a junk yard for free and soldered into place.

Considering you're running an S-trim and stage 2 cams, you're probably spinning that blower over it's efficiency range and getting some of the added power from the extra timing SS uses. I would be careful if you're on stock pistons.

 

[yamahaSHO]

The car has no intake charge cooling yet. Water injection very soon (at the least). Who knows maybe a 15psi pulley in the future after the tuning gets nailed and I become comfortable with the TwEECer. So I would say its going to see a bit more power.

What size pulley are you currently running? With the added lift and duration of those cams, your boost readings will be lower, but you'll be getting some major power at the given boost level.

Im just trying to decide between the 80mm and the 90mm. And also if the 44lb'ers will be sufficient.

Either MAF will work, but you may want to get larger than 44# injectors if you're looking for serious number (if you can't bump the fuel pressure). If you start ******* and 80mm MAF, then you can upgrade to the 90mm. I know the 80mm can be had for dirt cheap.

Its going to the dyno after I get the TwEECer.

Tune it first, then go to the dyno. You do not need a dyno to tune the car for safe, reliable power.

 

[40BelowSummer]

I agree with Chris, the 36# injectors are way too small for that kind of power. With the TwEECer, you'll be able to see how much work those injectors are actually doing. 44 or 48# injectors would suit you better.

Don't bother using the LPM program as a base tune. The best thing you can do is get smart about what needs to be done and modify the stock program. The 80mm MAF from the Lightning will probably be all you need, and like Chris said, no modification is required aside from a new harness connector which can be had a junk yard for free and soldered into place.

Considering you're running an S-trim and stage 2 cams, you're probably spinning that blower over it's efficiency range and getting some of the added power from the extra timing SS uses. I would be careful if you're on stock pistons.

Thanks for the insight, for now I guess Ill wait for the TwEECer and probably order an 80mm MAF. The pistons are 9:1.

Thanks

 

[40BelowSummer]

What size pulley are you currently running? With the added lift and duration of those cams, your boost readings will be lower, but you'll be getting some major power at the given boost level.

Its currently an 11psi (cant remember size) pulley.

Either MAF will work, but you may want to get larger than 44# injectors if you're looking for serious number (if you can't bump the fuel pressure). If you start ******* and 80mm MAF, then you can upgrade to the 90mm. I know the 80mm can be had for dirt cheap.

Good point. I noticed the 80mm is a bit more inexpensive.