We just got back from the Fbody Gathering in ATL. ChrisFormula ran his 1989 Formula 350 on the dyno at Dynolab. The results were kinda interesting and disappointing. Here is his setup:

1989 Formula 350 TKO 5 speed
Paxton SN93 (6 psi), Edelbrock runners, SDPC intake, Vortec 063 heads, LT4 HOT cam, Roller rockers, SLP 1 3/4 headers dual cats and SLP "Loudmouth" exhaust without the resonator.

He pulled 290.8 hp at 4400 and 398.8 tq at 3200, The air/fuel stayed right around 13.8:1 the entire thanks to Ed Wright's custom chip. The TPI wall hit HARD at 4200 and the power was falling hard when he hit the rev limiter at 6000 rpm. The graph wasn't shaky or bumpy. There were no peaks or valleys. It was climbing fast until the peak at around 4000 then fell hard....

I would like to see this combo with a Miniram 3. The long runners just simply will not let it pull up high.

I will post the graph ASAP when I get it from him.

 

Something is wrong with that setup. My N/A stock ported headed car put down 288rwhp with a hotcam and that is through an unlocked auto with a stock runnered TPI. I would say it needs a LOT more fuel for one thing. A boosted car should in the 11 to 1 range, not 13.8 Get it some fuel and strap it down again!

I would not drive it as it is as it will likely rattle itself to death quickly.

Charlie

 

I would have to agree. Those are some low numbers for a supercharged car. Get it some fuel and see what happens.

 

I was thinking the same thing about the fuel, but a call to Fastchip "confirmed" that this was the correct a/f ratio. He has an FMU ready to go it now. The only problem now is what step up ratio to use in the FMU (12:1, 6:1< etc>) Any ideas? The factory O2 sensor is almost utterly useless over 3500rpm in his car. It read totally different from the wide band at the dyno.

By the way, the Gathering was freaking awesome!!!! I am hooked now. I live 50 miles from ATL and have never been to the Gathering.....

 

Also, we put the 11psi impeller from my SN93 in his tonight. Now there is NO power above 3500rpm. His A/F gauge pegged dead lean before he could let out of it. I dont know how accurate that gauge is..... I would say that it is close enough for guess work.

 

what size injectors is he running? does he have an afpr? those things will help out the fuel problem a bunch.

 

I really would get the correct size injectors and tune it in the chip, rather than using an FMU.

The FMU will work temporarily though. A 6 to 1 step up ratio will work and they are adjustable, so you can get it close. If he is running a stock fuel pump he needs to put a Walbro in tank in and get rid of that problem too, especially if he runs a FMU as the additional fuel pressure will make the pump work even harder.

That thing will not live long that lean and adding more air is the last thing it needed! Get it fuel quickly before it grenades!

 

Yeah, he has the Walbro GS pump and FMS 42# injectors. Getting the tune is proving to be a problem. He doesnt want to burn his own and no one within a reasonable distance will do a dyno tune and burn chips. Its tough to find a dyno that has a wide-band O2...... Most shops are so backed up that they want you strapped down, do your 3 runs and get out of they way....

 

The MAF is pegged 255g/s at a little over 4000, and the FPR is set at about 52psi.

 

He certainly shouldn't need an FMU if the thing gets programmed correctly then. I would much rather see it rich than lean. What did Fastchips program it for, the 6psi or the 9psi boost or was it N/A at that time? Also remember that when you throw more air in you need not only more fuel, but less timing. Ed has done enough of those things to get them closer than that. If it is the program for that setup, I'd send it back to Fastchips and have him add some more fuel where it needs it. 11.5 to 1 to a MAX lean of 12 to 1 is where it will run best. A blower car uses the fuel to cool the intake charge and combustion chamber to prevent detenation, which is likely what is causing the lack of power (as well as eating the bearings and killing the rings).

 

The programming is for the 6 psi but the guys at Fastchip said that they had never burned a chip for a blower car without an FMU. They were very adamant about using a Vortech FMU, although they couldnt say what ratio to use. Fastchip told him that they couldnt be responsible for the WOT A/F ratio without an FMU. They went on to say that if he drove the car to OK that they could get it spot on for him.

I have had one fuel injected car in the Teens ( 10.18 @ 134) with NOS, but this is my first experience with boost. Thanks for all of the info!

 

Also, he has a MSD BTM box but the timing retard makes little difference in the power output because of the lean condition.

 

There is some BSing going on there then. I had Ed tune my wife's ATI procharged 383 LT1 with no FMU on his dyno(462rwhp). It is safer to not use an FMU than to use one, simply because they can be prone to failure and cause a lean condition. At the power level he is at there is absolutely no reason to use an FMU. I would assume 375-425rwhp is pretty close to where he is expecting to be and those injectors can do that no problem. They are giving him the run around and need to be called on it.

 

Fastchip told him to bring the car to them for a dyno tune or else use a FMU. The car wouldnt run on the factory chip when we put this engine together, so a mail order chip from Ed was the only route. Now that his Formula will run on this chip, the fact still remains that Fastchip is a good distance to drive from Georgia.


My girlfriends 1992 Formula 350 has a ADS custom chip with a Paxton SN93 and has no problems probably due to the MAP sensor as opposed to MAF.

I think that if he drove the car to Ed's shop that they would make it right. No doubt. This is the second upgrade the he has had from Fastchip. This is the only one that is radical enough for a "hands-on" dyno tune though.

 

Ed should be able to get his fuel ratio close if he had a copy of his A/F ratio printout from the dyno.