PowerLabs

No need to record our calls Guy, you are right and I will say it again here. Here is what I found out:
My car dynoed just shy of 600RWHP when it was able to run full timing. I don't have my tune in front of me right now but the requirements for that were something like sub 196F coolant temperatures and sub 80F IATs; under those conditions, it can push 16 degrees total timing and it will make between 589 and 598RWHP depending on the day and the dyno it runs at.
I show up to the drag strip, put my car in a huge line of cars, and its starts getting hot. By the time I line up to take a pass, my coolant is hopefully still sub 196F, but my IATs have already gone past 105F. The world's best Intercooler can't do anything when the airflow through it is zero.
With 105F IATs, my commanded ignition timing is now 14.5 degrees (ballpark numbers here). At 14 degrees, I know it dynos around 550RWHP.
By the time I have crossed the traps in 4rth gear, my IATs are over 122F, and the commanded timing is now 11 degrees. The car is now probably making 500RWHP tops.
A dynojet is no different from a pull on the road; you put your 3100lbs car on top of a 3000lbs roller and go full throttle; Force is acceleration divided by mass and there is your torque readout... Torque times RPM / 5252 is power; no magic there: If a car puts down more power everywhere on the dyno, it WILL be faster so long as the conditions remain the same. A track s different because you are not in one single gear and the heatsoak has an enormous effect. I was able to verify that on a 60 to 150MPH pull my ignition timing remains the same minus 0.5 degrees; I would be AMAZED to see a heads/cam car pull on me from those speeds. On the track, I imagine the H/C car can sustain near full timing, so it will have an advantage so long as the F/I car is battling heat soak. If I could pull up to the staging line, shut it off, let it cool down, turn it on and then do a pull, it'd be a slightly different story. I also know driver skill plays a factor, because 129MPH was the BEST I've been able to do, and it took a few tries. I get a little better each time, but I am not a drag racer, I don't like it, and I'd much rather do roll-on pulls on the highway against sportbikes... But that's illegal AND many of my friends are drag racers, thus I take it to the track once in a while.
Doug mentioned this a few posts up also

You will recall from that phone call that I also mentioned logging my friend's 780RWHP methanol injected car. He started his run with IATs nearing what I saw on my car. He ENDED his 1/4 mile run with 40F IATs... On a 73F day... I think Methanol Injection is a pretty good way of levelling out the playing field and now I understand why guys running boost are so fond of it. Under those conditions my car running meth might start that 1/4 mile pass making 580RWHP, and end it making 620RWHP. I can flat foot shift with my Lingenfelter launch control, so that means ZERO boost loss on shifts (throttle never closes, blow off valve never opens). Now where did the disadvantages of FI go?
There is a methanol kit sitting in my passenger footwell right now. It goes in when the new engine gets put into the car. I expect that this IAT vs timing retard issue will be gone then

DOUG @ ECS

Feel free to give us a call if you would like to discuss this in length. 609-752-0321


PL, the meth injection definitely levels out the IAT's, it's a great help on many levels. If you had it prior to your engine failing, I personally feel you would still have that engine in the car today since you were near what we consider the upper HP level of safety on pump gas.
Also, again I agree that anyone going for the "top spots" of the ET race in any category doesn't lift on shifts.


Spin, PM Jay (4DRUSH) he ran 10.7's (only a tenth away from the quickest H/C car) when he only had our base kit with nothing else, that was with a 346 in a 97. That was our base tune, and he did not race at that time, so it was the same level of tune that we would install in any car. (not trying to get into your debate, just stating facts. Nor am I against what your saying by any means.)

SpinMonster

What happens on the street with cold air forcing its way into the likes of vararam type intake systems have been shown to help N/A cars to the tune of 3+ MPH and .3 secs off the ET while the lowered radiator assembly on centri s/c cars hurts aerodynamics.

You are also not having weight transfer as efficiently with an extra 60? lbs on the front of the car also changing the weight to power ratio. These things add up.

I guess you allowed for that with the 'conditions' not being the same.

You keep saying the trap speed varies but it doesnt by much from best to worst driver or conditions. In most cases, as a great driver dials in, the MPH is actually lower. Cars that spin a bit off the line actually trap higher, not lower.

Its irrelevant to the discussion because its an order of magnetude different. 600rwhp N/A cars trap near 140mph and you are comparing your 129 trap speed to cars that are 100hp lower. C6Dvl's 128 trap speed was at 485rwhp on ECS' dyno.

Andrew just made a 129 trap speed with a cam only swap on his LS3 at 500rwhp. That represents a bargain that for only 2000 bucks you can trap 129.

Anyway, there were quite a few cars mentioned with this comparison and you seem to want to only talk about your car with you driving it. I mentioned two A6 cars differing by 80HP both driven by top shelf drivers. Talk about that match up and drop the variable of your driving skills.

I think people have enough info from both sides of this to make an informed decision.

SpinMonster

Haha, you opened a bigger can of whoop there.

The C5's H/C record is even faster with less power. The 10.56 @ 130.5 was done by Cartek with a little 228 cam and it only made 456rwhp!

Everyone remembers the LG run that day that also did about the same ET and Trap speed.

Phil Thomas running in a heavier Coupe ran a 10.66 using a 230 cam on a home brew H/C install. (Phil97svt). It wasnt even a tuner car. It ran TEA 5.3 liter heads.

Anyway, one thing for sure, ECS does have one of the best H/C packages in town so everyone should know where to go for N/A or FI. If its FI, the restrictor plate kit is the best chance you have of being as fast with a base kit. I fully endorse that kit and I own it. Mad TQ down low people....TQ wins races.

DOUG @ ECS

thanks Spin!

NormWild

Spin, not like you to Internet Race What you fail to mention is the technical reason, IYO, is the reasoning for this. I am more interested in the explanation, such as Sam's inference toward heat soak impact on timing. Two cars, most things being equal, will have the car making 100 more whp winning a top end roll race everytime.

If this is not the case, than higher hp car is losing significant hp during the run, or is not really making the claimed hp to begin with. I am referring to top end runs, not at the track. To me the track is more about your overall set up and experience and less about dyno numbers. You also mentioned that spinning at the track will yield higher traps, not sure how that is possible.

carlrx7

i greatly skimmed over the poop in this thread, but had to point out, its not the lack of timing that causes the loss of power, its the density of air that fills the cylinder that reduces the power. timing is just part of the combustion process.

cheers

-carl

PowerLabs

That is not entirely true; you can see that by filling your tank with high octane race fuel and retuning. You will find that ignition timing on a boosted LS2 is knock limited; you can pick up power by adding timing and leaning it out on race gas, and you can also run more timing despite high IATs with high octane. Under those conditions the power loss caused just by the density decrease is a lot less than the kind of power you lose by pulling back 5 degrees of ignition timing because the engine will knock severely if you don't...

PowerLabs

Yeah, I'm not either but that is a completely different discussion.
My feedback is that on a high speed pull the car makes every single HP you see on the dyno. I have a datalog showing IATs at cruising equal to 46F at 61MPH (45F day). I stop the car for a moment, the IATs immediately climb to 48F, then I do a full throttle run to 160MPH. At the end of 1st gear I am going 48MPH and the IAT is 48F, at the end of 2nd gear I am going 73MPH and the IAT is 54F, at the end of 3rd gear I am going 100MPH and the IAT is 66F, I shift a 6500RPMs in 4rth at 148MPH with the IATs now at 84F. At 145MPH the IAT finally becomes high enough for the ECU to pull a single degree of timing. From 150MPH to 160MPH the IAT stops climbing and stays at 86F and the timing is 15 degrees all the way.
The heat soak you get sitting still is the real killer, because it takes a while for that heat to go away. If I started at 86F I'd already be losing a degree of timing and then the IATs might climb another 30+ degrees from there...

LS1LT1

Though it should also be noted that aside from being a 6.0L (versus Andrew's 6.2L), Dennis's car also has what most will consider 'inferior' LS2 (stock 243 castings) heads and is also an automatic which will trap slower than a manual every time, all else being equal.
Andrew's car was also lacking many of the same bolt ons that Dennis's car has as well so for few different reasons those two cars are not a true apples to apples comparison.





As long as the reservoir remains full and as long as the pump continues to work properly, meth injection is a win win.

jpee

Someone correct me if I'm wrong, but from reading this post it appears everyone is talking about just "ONE" race down the track...

Which engine would you prefer (Spin, or Chris ECS) if you were in a "Bracket Race" with 70-80 other Vettes, and had to "Dial" your ET and run within .02 -.05 to be competitive? Remember as the engine heats up the performance will change..

So if you are FI and win round #1 you have 30 min + before you have to run round #2, so all is well....

You win the 2nd round, and now those 80 cars are down to 20 and your cool down time is less... but with an electric water pump & fan its doable to get you engine temp back down.... however overall can you "Honestly" say a FI engine is as "CONSISTENT" as a NA engine..

Just look at NHRA SG and SC and Comp Eliminator (Supercharged engines are permitted in those classes, & I can count them on 1 hand... out of over thousands of SC & SG and Comp Eliminator cars.. almost NONE are FI!

WHY ?? They are not as consistent as a NA engine, But in Top Alcohol about 1/2 the cars are blown, but still the UNBLOWN Nitro cars are faster (in general)

Any thoughts on this? Yes I would like a big blower sticking out of my hood if I were going to the weekly "Cruise Night" at Burger King but if I wanted to WIN at the Sat. night Bracket race I'll take a NA engine any day of the week!!

SpinMonster

Internet racing? You may be joking but for those who arent sure.......I quoted factual track runs to support the position using 10 cars on a drag track. It isnt internet theory when you show factual runs with a mod to demonstrate your point. I suppose if I go to the track with two cars, base FI kit on car 1 and a H/C kit on car 2 and come here to talk about it, thats internet racing because, I'm typing the results on the internet?

As for the tech reasons you say I didnt say, I think you skipped a few posts so I gathered them in one place for you.....ALL ARE FROM THIS THREAD.

To support this quote, I quoted the following:


Reason 1: Lost Boost Pressure

Reason 2: Tuning related IAT induced timing losses

and



Reason 3: Higher HP car owners avoiding gearing:
Affecting ET:

As far as your roll-on race statement: roll on races that dont lose boost pressure or incur high IATS from using a sole gear or two for the race I already said:

and

PRE-Z06

avg power is what wins races and you don't need a huge cam, as I trapped 125 with my tiny 218* cam in positive DA. It still gets 30mpg with 4.10s and idles at 725rpm undetected. You can't fairly compare runs from different days, much less different tracks...Powerlabs have you ran any h/c cars from a roll? Also curious how your car would do in the mile...

SpinMonster

Yeah because Subfloor's cali run had an unfair advantage over another car also with an A6 run at Atco will 100more hp.

HC Mechanic

The main issue for me regarding going to FI on a Corvette is, it comes down to weight distribution, reliability, and being practical.

A Corvette is made to stop, turn, and accelerate. All important aspects for having a really nice daily driver, or weekend toy. If you want to have hp bragging rights then go FI

For me, the Corvette is my favorite street car. And unless you plan on racing to over 140mph on the street(), I don't really see any advantage in going with FI. Unless of course you live in a place of high elevation.

Hope I didn't offend anyone, or come off as pushing my biased opinion, but from what I've gathered FI is just not practical

LS1LT1

That is a valid point, a supercharger along with it's intercooler and associated plumbing/bracketry does in fact add some weight (and yes, power ) to the nose of the car, upwards of 75 pounds I believe. The power one usually gains far more than offsets the extra weight but unless some other weight is removed from the front half of the car (and/or added to the back of it) then the car's balance could become slightly upset.





Not that it really matters but are you talking about just superchargers here or do you mean power adders (supercharger, turbocharger, nitrous) in general?
I don't necessarily disagree with what you're trying to say (I too, in general, prefer naturally aspirated power) but many people often cite one of the benefits of using forced induction is that it actually helps maintain that street car feel. That going with FI or nitrous allows one to use a less radical cam, maybe even use more highway (fuel economy) oriented type gearing which could in theory make a car more street/daily driver friendly than a high strung, high compression, lumpy cammed NA set up might yet still run pretty damn fast as well.
Again just a theory of course.

PRE-Z06

I'm speaking of DA for one, but if you've run at multiple tracks...you'll notice that some mph better than others, all aren't created equally... as is the case with the 2 local dfw 1/4 tracks and even subfloor stated the other track he runs traps differently

PowerLabs

For whatever it is worth I daily drive my "not practical" 600RWHP supercharged C6 to work every single day, 30 miles each way, and take it on 2000+ mile road trips on a regular basis. I drove it all of last winter as well, snow and all. I put just under 30,000 miles on it in one year, with stock driveability and near stock fuel economy. I would say a big loping cam with surging and bucking is impractical, but maybe I'm just too young to have lived back in the days when those things were "cool"?
I teached my girlfriend how to drive stick on this car. THAT is how civilized it is.

As far as weight distribution. My supercharged car is lighter than it was stock, and has perhaps 0.3% more weight up front? Imho if you can feel that you should be racing formula 1. In fact, my car will run circles around any stock C6 or C6 Z06 since I have upgraded shocks, swaybars, a performanc alignment and run racing tires on all 4 corners; the handling is every bit as impressive as the acceleration, and that's considering the fact that the car weights just over 3100lbs and puts down as much power to the tires as a Ferrari Enzo makes at the crank

NormWild

Thanks for clearing that up, I obviously missed your explanation in your previous posts, and I was of course kidding on the internet racing thing.

SpinMonster

Having been in 4 cars that ran 10.6 1/4 mile runs, I have yet to be in one that bucked and surged.

Is there a specific cam you are referring to?

Its getting tiring reading about this set-up you keep talking about.

You really need to meet up with C6Dvl to be teached about how civil cars that trap 132 without a supercharger can be. His cam is the biggest of the cars I was in. You may want to send this guy you know with that bucking and surging cam to ECS for a new faster combo or at least a retune. Or is it you cant find real things to say about H/C cars so you stay with the mythical issue you think people will care about?

My car as well as every car I did a H/C swap on all exceeded stock fuel economy. My car averaged 29.8mpg based on miles driven divided by gallons purchased on a 1100 mile each-way trip to Phenix City Alabama doing 85mph on average. The DIC noted 32mpg on the hiway. This was with 4.10 gears.