Too aggressive? Safe? What do you think?

 

i just got a S-AFCII it took me 4 hrs to put it on but damn was it worth it. I took it to a dyno on saturday and tuned it, i was upset with the first pull with no corrections and pulled 198whp. I started at 2,000rpm in 4th gear to see my fuel curve through the rpm range, man was it running rich... after 8 runs of tuning it i put down 240whp and 237 ft of trq. 310 dollars for the S-AFC is worth 40whp! here's my setting for hi thrtl. 1000-3400rpm no correction, 4000rpm -7% 4600 -7% 5200 -13% 6200 -13% 6400 -14% 7000 -16% 7600 -16% and the Th. Point is 35 and 75
enjoy! and holds boost like no other

 

Dyno'd on MAC Autosports' DynoJet in Denver, roughly 5,500ft above sea-level.

The results were as follows:

1st run:

- Pulled air filter.
- MBC at 18psi peak, tapering to about 16psi at redline.
- Uncorrected - 229 HP / 242 TQ
- SAE corrected - 279 HP / 294 TQ

3rd run:

- Pulled air filter.
- MBC at 20psi, tapering to about 17psi at redline.
- Uncorrected - 235 HP / 253 TQ
- SAE corrected - 286 HP / 308 TQ

No other mods. Prior to fitment of the MBC I would see ~18.5psi peak tapering to about 15psi at redline, so my BC settings for the first run are fairly representative of stock boost control IMHO.

The air filter has been on the car for 7k miles and was pretty much black. Hence I pulled it to simulate what I might see with a high flow foam cone.

Raising the boost that extra 2psi made a significant change in my AFRs, resulting in them dropping below 10:1 at ~7,300 RPMs instead of 6,800 RPMs. The car is generally rich (<11.5:1) from 5,500 RPMs on up.

For the record, most stock EVOs seem to show about 200WHP on this dyno. I seem to have something of a factory freak.

Regards,

-Pace

 

SAE corrected. I don't pay too much attention to this as the SAE correction factor does not apply well to forced induction cars. But it's useful to compare for anybody else that has SAE corrected charts.

-Pace

 

That's the truth as I just found this out last week. My stock SRT-4 put down an extra 253hp 275.9 tq uncorrected at DynoPro's in Denver Co. That's using a correction factor of 1.2 which increased the output an additional 43hp & 46ftlbs if you look at the corrected numbers

Corrected


Uncorrected


Air/Fuel Ratio



When comparing the uncorrected numbers to those at sea level, mine are only about 10-15hp lower. SAE...not always what it seems

 

how bout post up a real dyno chart?? notice the TCF. notice that ist set at 1.24 that means there is an additional 24% added for the transmision correction. that would me you had about 225hp with out the transmision correction......

 

we went down to knowledge performance over the weekend to finish up the evo we have been working on.

we had really good results.

303.7hp 314tq

all it has done is a RMR hard pipe kit, hks downpipe and exhaust, stock cat and converted to speed density. we managed to get the boost to hold fairly steady at 21ish psi. the intake temps were sky high on the dyno, easly 30deg higher than what we see on the street.

ill have the dyno graph up soon

 

Here's a quick review for those that may not know the differences,

Advertised Horsepower
Surprise! Those horsepower numbers presented in advertising and brochures aren't always accurate. Though manufacturers are supposed to base their horsepower ratings on SAE net standards, they are not completely beholden to it. They often fudge the numbers. Ford and Mazda both recently got in trouble with the Mustang Cobra and the MX-5 Miata, respectively, when they delivered a car that had less horsepower than what they advertised. Ford ended up doing considerable warranty work to bring the numbers up where they belonged, and Mazda re-rated their car and offered to buy back any offended customers' cars. General Motors regularly underrates their engines, most notably the GM LS1 5.7L engine as installed in the F-body (Camaro and Firebird) cars. Mechanically almost identical to the engines installed in the Y-body car (Corvette), the engine mysteriously "lost" 40 advertised horsepower in the F-body chassis. Although this technically is as fraudulent as selling a car with less than the advertised horsepower, no one seems to complain when they get a car with more horsepower than what appears on the spec sheet.

SAE Net Horspower
In 1972, American manufacturers phased in SAE net horsepower. This is the standard on which current American ratings are based. This rating is measured at the flywheel, on an engine dyno, but the engine is tested with all accessories installed, including a full exhaust system, all pumps, the alternator, the starter, and emissions controls. Both SAE net and SAE gross horsepower test procedures are documented in Society of Automotive Engineers standard J1349. Because SAE net is so common, this is the standard we will use to compare all others.

Testing, Testing
Factory ratings are all well and good, but many enthusiasts modify their cars and then want to see how much of an improvement they got from their labors. The problem is that most of the time people are not interested in ripping the engine out of their car to have it tested on an engine dyno; no, they're going to be testing on a chassis dyno. The most common chassis dyno, the inertial dynamometer (popularized by DynoJet), measures the horsepower as delivered at the power wheels -- whether front or rear.
But testing rear-wheel horsepower (rwhp -- obviously, front drivers would be measuring fwhp) makes it difficult to convert from what the dyno says to what the manufacturer says. The manufacturer, remember, measures horsepower at the flywheel. All that equipment between the engine and the wheels -- the transmission, driveshaft, differential, and axles -- introduce friction and inertial losses summarized as "powertrain loss" or "parasitic losses". The efficiency of the driveline can greatly affect the amount of the powertrain loss: Ford's AOD transmission, for example, is notoriously inefficient. As a very general rule, rear-wheel horsepower on a manual-transmission car is about 15% less than SAE net, and rear-wheel horsepower on an automatic-transmission car is about 20% less than SAE net.

Even looking at dyno numbers, though, it's important to exercise some caution. Dynos measure horsepower under the conditions of the day, then apply a mathematical conversion to bring the numbers in line with SAE J1349. The raw numbers can vary substantially. In one dyno test of a 1998 Firebird conducted several days apart, the same car ran a raw number of 284 horsepower one day, and 299 horsepower on a rather colder day. Corrected, both numbers were within half a horsepower of each other. The corrected numbers are useful for comparing this car to other cars, or the same car after different modifications spanning a long time, but in the real world a car's horsepower isn't corrected: on a dragstrip, the Firebird would have been about a tenth quicker on the day it was making 299 horsepower than on the day it was only making 284.

Things get real interesting when the numbers don't add up. Dyno testing proved that General Motors was lying about the low horsepower numbers in the F-body when compared to the same engine in the Y-body. Hot Rod magazine gathered a collection of performance cars and dyno tested them for the May 1998 issue. They found 292 rwhp for a Firebird Trans Am and 286 rwhp for a Corvette. The slight difference between the cars is likely due to varying build tolerances; certainly not enough to say one engine's design is notably different from the other's. Either way, the LS1 is looking at about 340 SAE net horsepower in 1998, nearly on the money for the Corvette's factory rating (345) but way aboveboard for the Firebird's (305). By comparison, the 1998 SVT Mustang Cobra was also rated at 305 horsepower but on the dyno it only delivered 257 rwhp -- just right for a 15% powertrain loss. And the chart on this Camaro page seems to support the underrating of the F-body cars by looking at the performance numbers it posts compared to other vehicles with higher rated horsepower (and higher price tags). If you'd like to read the whole atricel go to the Source: http://neptune.spacebears.com/opine/horsepwr.html

 

http://www.eurospeedperformance.com/evo.htm

 

WOW!!!

 

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Just dynoed mine last week, got on 91 ****ty cali gas on a new dynojet

238 whp and 260tq. on bone stock EVO with one miss match tire as well. they told me these are really good numbers.

 

That would also mean that I only made 176 WHP with a catless turboback and AEM intake.

Sorry, but the correction factor is correct for their dyno.

 

be that as it may, i know how dynapack software works.. (thats what we have at our shop) TCF will severly throw the numbers off and should ALWAYS be set to 1