Finally spoke to on3 performance

[fast 94 5.0]

Gets shipped out with in 2 days from purchase..MP turbo is out of business so they daid they got cermic ball bearing turbos for $410 upgrade with kit..is that a good tubro? Idk turbos(noob)

[Trojan Horse]

Yes, a ceramic bearing Turbo is a much better Turbo than what they originally offered.

[fast 94 5.0]

If im on 30lb injectors how much boost could I run..i know not alot..like 8?...i do plan on doin upgrade injectors just wanna get the turbo put in then upgrade.fuel..dont wanna spend crazy money at one shot

[Trojan Horse]

Well let's see the formula to estimate your power is:
One Atmosphere + Boost PSI /One Atmosphere x NA HP (305) = Estimated HP


14.7 + 6.0 = 20.7 /14.7 = 1.4081632 x 305 = 429 HP = 42 lb injector needed at 40 PSI of fuel pressure, using a BSFC of .60 for a Turbocharged engine and an 80% duty cycle.

14.7 + 8.0 = 22.7 /14.7 = 1.5442176 x 305 = 470 HP = 46 lb injector needed at 40 PSI fuel pressure, using a BSFC of .60 for a Turbocharged engine and an 80% duty cycle.

4.0 lbs boost requires a 38 lb injector & 2.0 lbs of boost requires a 34 lb injector.

Fuel Injector Size Calculator - Scroll to bottom of page.

[fast 94 5.0]

Soooo I need min 42lbs injectors lol..i guess I need to do n upgrade

---------- Post added at 12:53 AM ---------- Previous post was at 12:51 AM ----------

Im at 30 now n my friend who has a boosted stang says go straight to 62lb n booossttt lol

[Trojan Horse]

Originally Posted by fast 94 5.0

Soooo I need min 42lbs injectors lol..i guess I need to do n upgrade

---------- Post added at 12:53 AM ---------- Previous post was at 12:51 AM ----------

Im at 30 now n my friend who has a boosted stang says go straight to 62lb n booossttt lol

Yes, you should to keep from running lean and burning a piston or 8.
I would definitely think ahead and size them for future mods to keep from having to buy new ones later. You should be able to have it tuned or tune it yourself with a PMS/Wideband to make most sizes work.


I'm going with 60 lb injectors (Siemens DEKA) right off the bat with my SC install.
At 405 NA HP adding 8 lbs of boost should put me in the 600+ HP range, so I need to be sure I can feed those hungry ponies. I'm tuning mine with the PMS and a Wideband as I can't see paying a shop to do something I can do myself. The PMS is expensive, BUT in lieu of paying a shop I will still have something to show for my money spent and I can change the tune whenever it is necessary without going back to a shop.


P.S. Once you get close to 500 FWHP (Flywheel HP) you need to further modify your engine to withstand the HP. See the Superchargers & Turbos sticky thread for tips.

[90GTNovi2000]

I'm awaiting a reply from 93lx lol.. Him and TH have debated many times on this topic..

[Trojan Horse]

Originally Posted by 90GTNovi2000

I'm awaiting a reply from 93lx lol.. Him and TH have debated many times on this topic..

We have and I will still stick to what the experts tell me.
It takes a certain size injector at a certain pressure to supply the amount (lbs) of fuel you need to support any given HP.
There is no way you can get around that, period.
I'm waiting to see a Dyno sheet and A/F ratio readout.

[90GTNovi2000]

Lol.. Yeah I also go by the experts.. But 93lx sometimes states good points.. But why play with fire is the way I see it.. I would much rather avoid melting a piston!!

[fast 94 5.0]

My mechanic said my build is safe for low to mid 5s..so if im at low boost and like mid to higher 4s ill be happy for a while till I build up again

[dreamstang]

Originally Posted by 90GTNovi2000

I'm awaiting a reply from 93lx lol.. Him and TH have debated many times on this topic..

lol. i was thinking the same thing.

[Trojan Horse]

Originally Posted by fast 94 5.0

My mechanic said my build is safe for low to mid 5s..so if im at low boost and like mid to higher 4s ill be happy for a while till I build up again

A lot of people get by ok doing that, but I read some time back in the MM&FF mag, an SC company or engine tuner they were interviewing said that more 5.0 Ford engines have failed at below 500 HP than at or over 500 HP when boosted. That's when I started buying a stud girdle, windage tray & valley girdles for mine. I also intend to try and figure out some type of tensioning device across the front and maybe rear of the block and I'm threading the freeze plug holes and installing cast iron plugs for even more support and strength.


If money were no object I'd go ahead and order the Boss 351W block and forged internals and just build me a 427.