set up is in the sig. let me know if you guys think that 42's are too large. i have 36 lber's now.

Thanks!

 

What brand of injectors, what pressure?

Im running 36lb SVO at about 55 psi and thats good for about 600 flywheel HP NA

 

If they are Ford Motorsports ya will have to run 52+lbs of fuel pressure to make the HP that engine will be capable of making. Might want to think bigger,especially if ya got a small pump that won't take the extra fuel pressure.
Sure hope the duration is the Advertised or you ARE going to turn the snot out of it--say 7000+

My 42's at 52lbs make 680+FWHP@7000 but need to go up a tad to about 56lbs. I also have an Aeromotive 11101 pump and it can go there.
Remember up the pressure/loose the volume.

 

i have a walbro intank fuel pump. i think its a 240 or 255? i can't remember

 

Might want to check with Racetronics and see if it will stand that much pressure and still deliver the needed volume. They also make duel intank pump set up's that fit in the stock location.

 

42's will be more than plenty. You can make 530rwhp NA on a set of 42's which is hard to do in the first place NA.

 

im running 42's and all seems fine

 

Alvin,
Ya can make 650FWHP@7000 with a BSFC of .5 with the 42lb injectors @ 47psi with a 89.2%DC.
I am wondering if the pump is good enough to have the extra volume required to get there at 7000.
Have no idea of what the GPH is on a Walbro 255. If in fact it is a 255 and not a stock replacement(some doubt in the original post). I like to see the DC at no more than 85%. Don't know if that is good or not,just the way I have always done it since the Mustang days in the late '80's.

 

My experence going from engine dyno to chasiss dyno has been that you'll incurr in reality around a 22-24% loss threw a T56. It seems high but not really if you think about it because most engine dynos are just huge open tube headers (the one in our test where 1 7/8), no water pump, no alt, no driveline, rearend, tires, nothing.

I did one car last year that did something like 680Chp w/ EFI and we where pretty hard press to see 520RWHP threw a 10 bolt, hooker 1 3/4 LT's, 3 inch y and 3 inch borla.

I doubt this car will make more than 460rwhp especially with any LT1/LT4 intake but I don't know what the compressoin is like, the cam specs, if the heads have been touched up, etc..

 

You are probably right on the HP.

 

22-24% loss for a T56? I've got actual figures for my setup - steel flywheel Street Twin, stock T56, 3" Chrome moly DS, 3.73 Strange 12-bolt and street wheels/tires - from both engine and chassies dyno pulls, and the losses ranged from 12.5% at 500fwHP to 12.1% at 765fwHP. 22-24% seems excessive, even if you do assume the engine was run on the engine dyno with no intake, accessories or exhaust. Not having the driveline, rearend, tires hooked up is irrelevant, because that's what the "driveline" losses account for.

I've also got numbers for the TH400 with a loose, non-locking convertor, 4.10 gears and 28" slicks and the losses still only ranged from 19.8% at 500fwHP to 21.3% at 765fwHP.

 

The only thing I can tell you is that engine dynos are different than a chassis dyno. One could be reading high while the other read low.

Did you have a waterpump, alternator, PS pump, ac compressor, same size headers you ran on the chasis dyno? These things help. The car I was talking about just went to a 1 7/8's header and picked up 60ftlbs of torque down low.

 

Ran engine dyno with no intake (car is tuned speed-density, no MAF). Inlet system used in chassis dyno consists of a WS6 airbox, K&N filter and a Fernco sewer connector. For the nitrous eng dyno tests, we used a rubber sleeve over the throttle body, with the dry nozzles in it. For the chassis dyno the nozzles are in the airbox.

Engine dyno and chassis dyno had stock gear driven water pump.

Engine dyno used actual AS&M headers, actual collector adapters, and ran through the dyno cell's dual stack, muffled system. Chassis dyno used AS&M headers, collector adapters and a 4" Mufflex catback.

No A/C compressor.

No PS pump or alternator on the engine dyno, ran full serpentine belt system with alternator and PS pump connected and operating on the chassis dyno.

 

maybe i should just keep my 36er's and get a good computer tune? who should i go through for that though and how much does it cost? who makes 1 7/8 headers? i have hookers now and have been very pleased. let me know what you guys think.

Thanks!

 

FWIW, with a Moser Ford 9" (4.11 ratio), G-force T56, synthetic fluids, street twin, drag lite wheels and drag radials, I saw losses in the ~13% range.

-Mindgame