Forced Induction 1/4 mile times
- Thread starter black mamba1
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black mamba1
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Excellent point. I dont believe in having power just to have power. More power= more heat that this engine and its components simply were not designed to handle long term. I know about adding all the additional cooling chambers, etc., but I am also an engineer, and I know that these engines and engine components are designed to run cycles under a certain heat load. More heat = more wear = less engine life and more chance of catastrophic failure.A great job on the Pilots that day,Tony. Saw they weren't D.R.'s but as you said makes the point.
Keith maybe should ask where are all those big guns now ? Of the ones still around who are actually happy that they went for over 900hp ?
So its a trade off. Any forced induction engine is going to add more heat and reduce engine life and increase metal fatigue, etc. But exactly how much engine life is lost is not an exact science. So, if running at 700 rwhp makes my engine poop at 70,000 miles instead of say, 90,000 miles...so be it. The fun factor makes up for the difference in my opinion.
And I know about the argument of "dont knock it until u try it" when it comes to going to 800, 900, or even 1,000 rwhp. But I also know my car is plenty fast and plenty fun now. I aslo know how fast I close on traffic and and how fast things happen with my current power, so going to "the dark side" is not something that seems practical to me, or usable...so, 700-775 rwhp is enough for me at this time.
But...you never know.
Tusc
Enthusiast
Does anyone have the general rwhp/tq numbers for a 5# Roe kit on a stock engine with headers and full exhaust?
Steve 00RT/10
Enthusiast
Steve 00RT/10
Enthusiast
We got a strong one I guess. I think 540-560 HP is about normal. I got a dyno sheet with the car from the original install (Dynojet machine -- sniffer up the tailpipe) in 2003. It was 554HP/586TQ. After I upgraded the VEC to log and installed a WB, I found those numbers were produced with WOT AFR running 9.6 to 10.2 or so. I removed lots of fuel and am now running about 11.6 - 11.8 AFR. Sean told me this is the high end HP for a 5 pounder. If gearing works conversely....then the 3.07 gears with 19" tires (2.92 effective rate) might add a tad. A 2008 Viper, with the controller mod and exhaust, dynoed a couple cars after me and turned around 570 HP? 545 TQ? (or close). I can get the exact numbers if needed.
The lesson learned is always use a WB near the engine for more accurate dyno tuning.
Steve
Boy I tell you what - sorry to hijack this thread, but i'm a ferrari owner, and this is the reason why i'm in the market for a viper!!
These cars are just amazing!! I'm an inch away from kicking the italian to the curb!!
Just wanted to let you guys know!!!
Totally amazing and impressive! Thanks all!
Bobby
These cars are just amazing!! I'm an inch away from kicking the italian to the curb!!
Just wanted to let you guys know!!!
Totally amazing and impressive! Thanks all!
Bobby
Steve 00RT/10
Enthusiast
I have no clue. How do you figure that out? A quick look shows SAE gross HP/Certified HP/Net HP....with Certified being the newest?
Can it be determined from the dyno run?
Steve
Typically the dyno operator can simply change it from std to sae. The sae is the corrected number. I think it corrects to a standard barometric pressure, sea level conditions, and around 70 degrees ambient temp. When I dyno my car at a dynojet the correction factor(to make it SAE) is anywhere from 14-22%. I live at 4500ft and thus lose power becuase of the air density.
You will sometimes see guys dyno their car during the winter months at sea level and have a negative correction factor. It supposed to put everyone on a level playing field.
I see that your dyno runs were in the morning. If you had an unusually cold morning with very dense air then you might have a negative correction factor, if you are at sea level. However, more than likely your number will go up because it was probably not "ideal conditions".
You will sometimes see guys dyno their car during the winter months at sea level and have a negative correction factor. It supposed to put everyone on a level playing field.
I see that your dyno runs were in the morning. If you had an unusually cold morning with very dense air then you might have a negative correction factor, if you are at sea level. However, more than likely your number will go up because it was probably not "ideal conditions".
Steve 00RT/10
Enthusiast
I'll see what I can find out from the dyno guy tomorrow. We were 616 feet above sea level. Outside temperature was around the mid 50s
Steve
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black mamba1
Enthusiast
Just before I bought my Viper I visited the Ferrari dealership in Greenwich, CT, and then the Lambo Dealership in Manhatten. After I saw the Viper, drove the Viper, and realized its potential, it was case closed.
And believe it or not, Vipers are more "exotic" than Ferrari's in that there are fewer Vipers around than Ferrari's.
The final point that sealed my decision was how easily the Viper can be modified, whereas it is difficult and very expensive, very very expensive to modify Ferrari's, any Ferrari for meaningful power.
Welcome to the forum!
You will end up with a negative correction factor I believe (not knowing the baro on the day tested). Here is the formula. Note a 0 correction factor occurs at 25 C and .99 Bar (990 mB).
SAE J1349 Update:
In August 2004 the SAE released J1349 Revised AUG2004 which specifies that the preferred method of determining the friction power used by the motor accessories is actual measurement, and that the assumption of 85% mechanical efficiency (as formerly used in SAE J1349 Revision JUN90) should only be used when actual friction data are not available.
The equation for computing brake horsepower, assuming 85% mechanical efficiency, was very slightly revised (and is presented here converted to use pressure in mb) as:
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The J1349 AUG2004 revision also makes it clear that this correction factor is not intended to provide accurate corrections over an extremely wide range, but rather that the intended range of air temperatures is 15 to 35 deg C, and the intended range of dry air pressures is 900 to 1050 mb.
I've ran high 9's on invo's running 12lbs of boost. Car is a 98 TT GTS from UGR. Mine has a TH400 tranny, so can't compare to a 6 speed. I went 9.90's at rockingham on mopar day only going 6.65 through the 1/8th. It had rained for 4 days straight prior to event so mid track was a mess. I can drive to the track on pump gas and run 6.30's all day. Once the temps go down I'm confident I'll run 9.60's on 12lbs of boost on Invo's. Obviously could turn it up, but I don't think the ET will change that much, just the MPH. On pass time on speed tv, I blew the tires off midtrack, got sideways, got it straight and went through at 150 in the 1/4 on 15lbs of boost on Invo's.
Steve 00RT/10
Enthusiast
Per the dyno shop .... SAE corrected:
592.6 HP (std was 593.1)
616.8 TQ (std was 635.8)
The 2008 Viper tested pretty much right after me was 565.3 HP and 533 TQ. His runs were juxtaposed for results. His other run was 559 HP and 536 TQ (SAE corrected)
Steve
