The Horvaths
Young man with a cowboy hat
For those of you considering the FI Tech system or Trick Flow heads, this may be useful.
Mopar Magic
Mopar Magic
Engine Power Video
- Thread starter The Horvaths
- Start date
Dodge97318j
Member
Wish I had that build. I am super interested in the FITech for sure
D
Deleted member 4847
Guest
That carb beat the hell out of the FITech. I wonder if it was a limitation of the self tuning or ????
The Horvaths
Young man with a cowboy hat
I think they didn't give the FI enough time to tune. It could also be a CFM issue.
D
Deleted member 4847
Guest
I would think CFM wouldnt be an issue for a unit rated to support 1200 horses. Maybe the guy from FITech will chime in.
65sporty
Old Man with a Hat
I agree with the tune time, but I have seen this a lot with dyno tests where the carb makes more max HP but you will have better driveability with the injection.
70bigblockdodge
Old Man with a Hat
Carb usually beats FI at WOT. For a race car it works, for a street car FI is better with hundreds of feed backs and adjustments per minute, no way a carb can compete with that covering all the bases. I'm sure you can tune this problem away with time and effort.
heyoldguy
Member
And a 91 octane 440 with 240cc Trick Flow heads and a 6-Pack.
RPM.........TQ/HP
3500......559/337
3700......551/388
3900......550/409
4100......553/431
4300......546/447
4500......548/469
4700......543/486
4900......548/511
5100......553/537
5300......544/549
5500......543/568
5700......533/579
5900......522/586
6000......518/592.........end dyno run.
RPM.........TQ/HP
3500......559/337
3700......551/388
3900......550/409
4100......553/431
4300......546/447
4500......548/469
4700......543/486
4900......548/511
5100......553/537
5300......544/549
5500......543/568
5700......533/579
5900......522/586
6000......518/592.........end dyno run.
70bigblockdodge
Old Man with a Hat
Is that a stock stroke 440?
D
Deleted member 4847
Guest
Likely more power there, horsepower was still climbing when the pull ended.
heyoldguy
Member
Yes, it is a stock 3.75" stroke 440.
70bigblockdodge
Old Man with a Hat
Thank you great to know.
Landyacht
Active Member
How much compression are you running with the 91 octane? I was considering switching out my Eddys for a set of Trick Flows but the 78 cc chambers would bump my compression past 11:1. I called Muscle Motors and they told me they would port my Eddys for $1700. It would seem to make better sense to just pay the extra 3 or 4 hundred bucks to just go out and buy a brand new set of Trick Flow heads.
heyoldguy
Member
Of course this engine was designed to use the Trick Flow heads, and we wanted it to be able to run on 87-88 octane in a pinch, so it is 9.9:1 compression.
Our 787 HP 451 stroker ran 91 octane @ 11.7:1 compression. Desired service and camshaft plays a big part of the compression you can run.
Curious. Did Muscle Motors predict what cfm flow they were going to provide for their $1,700?
Landyacht
Active Member
I was told by them that the work would include cnc porting the runners, bowl work, 5 angle valve job and installing new valve springs. The cost would include everything, not just the porting work alone. They did not specify how much flow increase would be obtained from the work. I had only talked to them for a short period over the phone so not a whole lot of information was exchanged. I calculated that my compression ratio would be at 11.4:1 with the Trick Flow heads. I'm currently running a 470 stroker with 10.39:1compression, Performer RPM heads and intake, a .509 lift purple cam with 248 degrees duration at .050 lift in a 4300lb C-body with a 3000stall convertor and 4.10 gear.
To shed some light on top end HP, of EFI vs a carb...
MAX CFM is the limiting factor. If the TB unit only has a 885 CFM rating (the fitech) then any engine that likes more air than that would obviously do better with a carb (950 i'm assuming they used?)that supports said larger CFM requirement.
In this instance, it appears to me that the peak HP was 631 ish with both. Peak torque however was about 12 more.
there's no argument that in many efi vs carb dyno test the carb will out perform efi at peak levels. Which is why for drag racers...i really don't stray them from a carb to the EFI system. But for 99% of street/strip guys, that see most of their driving time NOT at WOT... i'd rather it not have issues with hot start, cold start, fuel evaporation, and jet changes, and sacrifice a few WOT ponies. Thats the whole concept of these bolt on EFI systems.
If an engines peak HP is better w/a 950 carb than an 850... peak HP will be affected the same way vs an 885 fitech. But again...the tradeoff is better drivability across the other 95% of the time you're in the car.
MAX CFM is the limiting factor. If the TB unit only has a 885 CFM rating (the fitech) then any engine that likes more air than that would obviously do better with a carb (950 i'm assuming they used?)that supports said larger CFM requirement.
In this instance, it appears to me that the peak HP was 631 ish with both. Peak torque however was about 12 more.
there's no argument that in many efi vs carb dyno test the carb will out perform efi at peak levels. Which is why for drag racers...i really don't stray them from a carb to the EFI system. But for 99% of street/strip guys, that see most of their driving time NOT at WOT... i'd rather it not have issues with hot start, cold start, fuel evaporation, and jet changes, and sacrifice a few WOT ponies. Thats the whole concept of these bolt on EFI systems.
If an engines peak HP is better w/a 950 carb than an 850... peak HP will be affected the same way vs an 885 fitech. But again...the tradeoff is better drivability across the other 95% of the time you're in the car.
Similar threads
