a turbo honduh, 20 bucks, and TSi

not at his altitude. ev

Food for thought
up here in ontario(canada, not california, the only reason we canadians know there is an ontario california is because it says thats where maglights are made) hehe
anyhoo
theres a guy with a nice type r
full interior
pushing i THINK 350 to the wheels on a turbo kit of undisclosed size
and he runs 12.5's or better on little mickeys(the very small ones)
so hondahs can be fast without gutting

which is good
as I have no respect for kids who drive around in hatchbacks with no interior

and whats worse
theres a guy up here who has a DEL SOL thats gutted
so you can see all of the ugly hardware that controls the rear window

Take a look over on probetalk.com and see if you can find pics of a guy named "Howlett" car. Hes got a fully stripped probe GT as in A seat a steering wheel a shifter and a big bottle of N20. That thing flies, and I think the power:weight ratio is 1hp gained for every 15lbs removed, so yea that thing flies, granted it's not the prettiest thing on the road but it can go. I'll look for pics I know I have some somewhere on this comp.

that's a tick ahead of a stock Z06.

Click to expand...

02 zo6 runs like 12.5's

not at his altitude. ev

Click to expand...

so at that altitude it runs what a 13.6 or a 14 flat.. BAHA it does not make a 1.5 seconds off .... its still going to be a low 13 second car no matter where it is. Also what your saying is that if its a TICK faster than a z06 at that elivation that means at closer to sea level it will run a 12.4? Hmm i dont think so.

But while we are on this subject.. What would a Superchagered (vortec blower kit) do to a Integra gsr... that is somewhat built but on stock injectors.. and running 11psi? Thats what the kid says he is on.. iv seen the superchager so i know he is not completely lieing.. but i thought it was odd he was on stock injectors pushing 11psi. But what could it do?

Wowza, do some research bucko... the truth is out there. 5000 ft ASL will hamper a... now say this with me... a "NATURALLY ASPIRATED MOTOR" by almost, if not more than a full second. Less air density, less power. Turbocharged cars aren't affected nearly as bad except for the MAF systems accounting for less density and perhaps hampering performance. If that car runs a 13.4 at altitude, it's probly a high 12 second car at sea level. The Z06 will get exponentially faster closer to sea level because ya gotta remember, all it can do is suck in the air around it, it can't force it in. So when it's sucking on a lot denser air, it makes a lot more power. Cold day vs warm day, think man. Go to some of the higher altitude track websites and look at the correction numbers... they are estimates but they're ok to at least get a roundabout determination of elevation's affect on ET and MPH. Ever seen a mid 14 second LS1 f body? Go to denver. Stop arguing, you're wrong. Todd.

Ok, now... read this:

The $15 Dyno
Or How To Get A Cheap, Accurate, Repeatable HP Estimate
By Bill Watson


--------------------------------------------------------------------------------

by Bill Watson

It's natural that with a group like Turbobricks, the talk commonly turns to power output. Even though the intent is good, the talk is just that: talk. Sometimes we all wish we could get free dyno time to see just what kind of power our cars are really making.

I would suggest that the most accurate CHEAP method out there is a trip to your local quarter mile dragstrip, which typically costs around $15 for a whole night of racing. We can argue out the accuracy and repeatability of engine dynos with rear wheel dynos with the dragway in another article.

The paragraphs below focus on the fact that you'll use speed instead of time as your yardstick, and the point is... YOU DON'T HAVE TO ABUSE THE CAR TO GET YOUR NUMBERS. That's the biggest excuse I hear for why someone doesn't go to the strip. You DON'T have to buy slicks, or do a neutral drop, or burn your clutch, or buy 4.10 gears, or even warm up the tires in the water box. IT'S EASY, NOW QUIT MAKING EXCUSES AND JUST GO DO IT. (Whew!)

Like it or not, the trap speed at the end of the quarter is an excellent indicator of your HP to weight. If you know weight (almost every track has a scale), then you can calculate HP. It's that simple.

Note that I have not used the term "ET" (Elapsed Time) yet. I have said TRAP SPEED, the speed of the vehicle by the end of the quarter mile. However, almost everyone involved with drag racing will discuss the ET, the elapsed time to cover that quarter mile. Yes, the two are related of course, but for all intents and purposes, here's what I hope you learn from this article;

1) Trap Speed will tell you about your HP to weight.
2) ET will tell you more about traction and your launch.

Of course ET is important to true drag racers, because the winner is the one that gets there first. However, we're not necessarily true drag racers in our attempt to get a power estimate. Honestly, ask 10 guys at the track "What kind of trap speed are you running?" and 8 out of 10 will answer with their ET - to one or two decimal places even. When you say, "No, no, I meant trap speed", they will fumble with a broad estimate with NO decimal places and might even have to pull a time slip out of their pocket to check. Try this question when you're at the track; it's almost funny.

THE DYNAMICS OF TRAP SPEED VS. ET

After running lots of quarter miles, it becomes clear that how well you do in the first 100 feet of the track is KEY to a good time. The last half of the track is KEY to a good speed.

Let's use an example of a stick-shift mini-pickup that on a perfect run, gets a timeslip of 19.50 seconds at 70.00 mph in the quarter.

Imagine that the light turns green, the truck moves two feet and the engine dies for three seconds. After restarting the engine, the driver proceeds to then complete a perfect pass. His time slip would show 22.50 seconds at 69.97 mph. The ET was 3.00 seconds high but the speed was almost unaffected.. why?? It's because his racetrack was 1318 feet long instead of 1320, and in those last two feet this truck usually gains an additional 0.03 mph. However, the clocks recorded the long time. My point? Much of a great ET is made by a great launch.

Now take this truck again, and the driver leaves right on the green light. However, he misses the 3-4 shift when he's at 1250 feet. He coasts for the last 70 feet while trying to find fourth gear. Now instead of accelerating another few mph in this final 70 feet of the track, he decelerates over this distance. His timeslip; 19.51 at 67.83 mph. Note how the et is almost perfect (only off by 0.01 second) but the trap speed is way off (over 2 mph slow)! On a good run, traveling that last 70 feet at an average of 69 mph, would have taken .692 seconds. At a 68 mph avg., that 70 feet takes .682 seconds. That's why his ET only varied by .01 seconds, yet the trap speed was 'way off'. My point here: the end of the track is critical to trap speed; shift rpm, missing a gear... these are the big players.

Hopefully these examples are clear. Neither of these runs are 'perfect' runs, it's just that one has an error at the start, one at the finish and the results are obvious. The start of the track is a big player in the ET, but a small player in the mph. The end of the track is a big player in the mph, but a small player the ET.

So for the casual T-Bricks member who wants to get a HP value, you don't have to buy slicks, or wish you had a limited slip differential. You don't really need to heat the tires in the waterbox, or launch with huge power braking. As long as people get their shift rpm right and don't miss a gear, even a rookie will get the appropriate trap speed for their vehicle.. but honing the perfect ET. requires being rude to a clutch, buying steeper gears or slicks.... hey, we're trying to make this recreational.

OPTIMIZING SPEED

If your goal is to get a good trap speed, what are your options? More power, of course - and less weight is obvious (but it will come out in the power calculations as no increase in power). Shift rpm chosen (auto or manual) and the time it takes you to shift (with a manual) are probably the most important tools you've got. Try different shift points to maximize your trap speed. Reduce rolling resistance by pumping up all tires to their rated pressure. Some people think that running lower pressure might help the traction in the rear, though. Of course more traction will help et, but with most street tires, running street tires within 5 psi of rated pressure will provide you with maximum traction in the first place.

REACTION TIME

The ET clocks don't start until you've actually moved around 8 inches (this is called the rollout)... so don't worry about trying to leave right on the green light. You could wait 5 seconds after the light turned green, and still get a 19.50 timeslip in our truck example above. Your timeslip does show a separate calculated time, the "Reaction Time", which in this case would be 5 seconds. That is the time from the light turning green until you rolled out of the starting zone. It's not a big thing for our discussion here.

THE LAUNCH

For the most part, a decrease in ET is accompanied by an increase in trap speed, but don't go overboard on the launch in your zest to rule the world. Just try to get smartly underway without spinning the tires much at all. Traction levels usually drop a solid 0.10 g when the tires start spinning.

THE HP FORMULA

Here's the formula to use to calculate HP:

Net HP = Weight in pounds* (Speed in MPH/228.4)^3

As an example, Car & Driver tested the 744 Turbo in their June 1990 issue. The car weighed 3,081 lb. without the driver.. the 'race weight' was 3,231 lb. The car ran a 15.7 second quarter at 86 mph. Let's plug it in to the formula:

HP = 3231 * (86/228.4)^3
HP = 172 Net

Volvo rated this at 162 Net. We come out a little high. Or does Volvo underrate a little? I'll say this - I've used this formula for years and that's how the 228.4 was honed - actual experience from cars that had actual power curves - and when I use it on Volvos it tends to always come out a few percent higher than the factory rating. This could simply be that Volvo underrates just a little.

Still, for such a simple formula and such a simple test, it's surprising how accurate this can be. And the best thing is - there's no arguing the numbers on a timeslip. There are always differences between a DynoJet and an Eddy Current Dyno, or G-Tech numbers, but every setup is done by someone different and subject to error. The quarter mile is arguably the best comparison a diversely located group like Turbobricks will ever have. The only real difference to argue about is the altitude of the track! You can compare ET and mph all day and have a good discussion.

HANDY RULE OF THUMB

Once you have a baseline, you should probably use a rule of thumb that each additional 6 HP will give you another mph. That's for a 3200 lb car that runs 88 mph. If you want the real formula for different weights or speeds, here it is:

HP for another mph above "X" speed: = Wt * (((X+1)^3-X^3) / (228.4^3))

For instance a 89 mph quarter vs. an 88 mph quarter for a 3200 lb car:

HP delta = 3200 * ((89^3-88^3) / 228.4^3))

HP delta = 6.3 HP

Once you're going 110 in the quarter, it would take an additional 10 HP to go 111 mph in the 3200 lb car.

60 FOOT TIME

This is the standard measurement tool to evaluate your launch. It's the time that it took you to travel the first 60 feet of the track. Naturally, patterns emerge again after looking at lots of runs and of course these correlate best to time, not mph. Typically, most everyone's 60' time will be between 14% and 16% of their quarter mile time. If it's under 13% or over 17%, this was not your best pass.

1/8 MILE VS. 1/4 MILE

After monitoring tons of good passes, patterns emerge. Typically, the mph at the quarter is around 1.26 times of the mph at the eighth, and the time at the quarter is around 1.55 times the time at the eighth. You can use these values if you only have a 1/8 mile track and get a real good idea of the theoretical 1/4 mile.

IS MY ET TO SPEED RATIO REASONABLE?

One fact of the quarter mile is; no matter how slow or fast your car is, the mph multiplied by the ET will pretty much be the same number every time. Before the NHRA changed the way that speed is measured in 1989, the product of speed and time was around 1400. Let's calculate some easy examples of this. A 14.00 et usually resulted in a trap speed very near 100 mph. A 10.00 et meant around 140 mph. A 200 mph pass usually takes around 7.00 seconds. These are still good rules of thumb to remember, but now the product is more like 1380 for us - The example from Car and Driver above comes out at 1350. (The reason for this shift is explained below). Remember, most everyone focuses on ET so much that they'll even optimize a car for slower mph if it gets them a better ET. (Rear end gearing is one way to do this). Those guys tend to have a product closer to 1300.

RESPECT MORE SPEED - A LOT. EVEN 3 MPH.

If you look at the formula again, you'll note how trap speed shows up as the cube root of power to weight. That's critical to understanding how fast one car is over another. Let's say your car does a 90 mph quarter and the guy who raced you in the other lane ran 71 mph. After the race, he wanders over to you to say the 'race was close'. Your reply: "I could have towed you and still beat you". (This might not be the best way to make friends, but yes, it is TRUE if the cars weigh the same.)

Do the math. (90/71) cubed is 2.04. Yes, the 90 mph car has 2.04 times the power to weight of the slower car. It has 2.04 times the acceleration of the slower car. It's just that the track is a fixed length, and in accelerating to higher speeds, you use up the track quicker. You accelerated to 90 in about 20% less time than he had to accelerate to 71, right?

Bottom line; Down where most of us run, a 3 mph difference between two cars is NOT a race. It was a clear win. There's a full 10% difference between these cars.

SOME MAGAZINES SHOW THE CONSTANT AS 230.5 OR 234.0. WHERE DID YOU GET 228.4?

Some people try to correct to different things. Like Gross HP instead of Net. But most commonly, these other constants that you'll see in magazines were originally published before 1989 when the NHRA changed their lights, and the 'new' journalist doesn't realize the formula should change accordingly. Here's what I mean; previous to 1989, there were three timing lights at the end of the track; one AT the end of the quarter mile, and one 66 feet before, and one 66 feet after. The middle light was used to calculate the et of the run, and the time to travel the 132 feet at the end of the track was used to calculate the trap speed. This gave the average speed at the end of the track, but you can see what this lead to. Most of the racers stayed on the gas for an additional 66 feet past the quarter to get a consistent speed to evaluate their setup. The track's 'shut down area' of course is a fixed length, but the pro racers were starting to hit 300 mph plus by the end. In an attempt to get these guys off the gas 66 feet earlier and 'make' the cars appear slower, the NHRA stopped using the last light around August of 1989. Today, the trap speed is calculated between the light at the quarter mile and the one 66 feet before. So any timeslip after 1989 is really giving the average speed 33 feet from the finish, which is pretty close to one percent slower than before. The old constant of 230.5 became 228.4 to compensate.

CORRECTING FOR ALTITUDE

If we were dealing with non-turbo cars, this would be easy and we'd publish a formula. But with pressurized cars, the correction factor for altitude depends on the boost you run.

For instance, Sea Level air pressure is 14.7 psi. If you go to a track in Boise, Idaho (2850 feet above sea level) the air pressure is now around 13.25 psi. That's 90.1% of sea level pressure. If the temperature doesn't change and you have an normally aspirated car, your power output will now be 90.1% of what it used to be, so I'd tell you to correct by multiplying your calculated HP by an extra 10.9% (1/.901, or 1.109).

However, (and this is the beauty of turbo cars!!) Let's say you were running 10 psi of boost in the first place. So at sea level, your car was really getting 24.7 psi (14.7 + 10). Now you leave the wastegate at 10 psi and race at Boise. Your manifold pressure is now 23.25 psi (13.25 + 10). Note that YOUR power isn't down as much.. it's down to 94.1% of what it is at sea level. So you should correct with an extra 6.2% (1/.941, or 1.062).

If you wish to calculate your own correction factor, here is a handy table of elevation (feet above sea level) vs. standard day atmospheric pressure (psi):

0 14.70
500 14.43
1000 14.18
1500 13.92
2000 13.67
2500 13.42
3000 13.17
3500 12.92
4000 12.69
4500 12.45
5000 12.23
5500 12.00
6000 11.78
6500 11.56
7000 11.34
7500 11.13
8000 10.91
8500 10.71
9000 10.51
9500 10.30
10000 10.11

Yes, the detail oriented will notice that I'm ignoring lots of small effects of higher pressure ratios in the compressor, lower density air across the intercooler and even the fact that there's less wind drag at higher altitudes, and they're right. However, the overall concepts above still hold true.

There's lots of discussion of 300, 400, even 450 HP on the Tubrobricks list. It would be great to see these power levels turn out to be true. Just keep in mind that an honest 300 Net HP in a 3200 lb Volvo (includes driver) will go just under 104 mph in the quarter. 400 HP would push it 114 mph, and 450 HP should propel the car to a trap speed of nearly 119 mph at Sea Level!


In terms of the ZO6, that makes for 19% less power at 5500' ASL (typical denver, there's a reason it's called the mile high city), so instead of 405 hp, they're making closer to 328 bhp. Argue on... Todd.

Re: Re: a turbo honduh, 20 bucks, and TSi

BigBADGSX said:

Sooo.....do you happen to know what motor he was running??? cause a built b16 and a turbo kit should be able to hang with you unless you have some good modds? IM IN NO WAY DOUBTING YOUR KILL shit IT WAS A just another honda with like 10k invested to run 13's LOL anyway just wondering what motor dude was running and what your modds where?

Click to expand...

I dont know the code for the engine but it was a sohc 1.6. My mods at the time included:
ported big 16 G, full exhaust, hard pipes, intake...

ElectronVTEC said:

Yea, some of us actually made Honda's fast and not tacky . Granted I sold mine for a 1G, but I still have a couple good stories.

First up: Classic case of someone's friends digging a large hole for them...

Kid in a 1G FWD Turbo Laser had some friends who didn't know when to shut up. He had a 19c (somehow, this turbo is real popular around here ), exhaust, free mods, MBC, basic stuff. His buddies decided to start shit with our friend who has a high 11 second Honda hatch. Apparently the DSM guy was going to win "because he has heart and soul" (let me tell you, we laughed for days at that comment). 1G DSM lost by about 10 cars, no joke. Kid was cool, but his friends were dejected and retarded.

Another gentleman in a '97 AWD "built by Extreme" GSX... at the track for our local "import shootout." Lines up against the same hatch, pulls 2 cars on the launch, proceeds to lose by about 4 cars at the end. 13.6 for the GSX to a 12.7 for the Honda. To this day, he insists that he ran 12.5 at the track that day, despite video of every run of his at 13.5 or greater . In fact, he told ME that, and when I told him I was the black/silver 1G running 12.9's he a.) wouldn't believe me that I had a 14B until I showed it to him and b.) never said another word about "how fast" he really ran. Polesmoker, 100%.

I had a Civic that ran 13.5's at 104.8 IIRC (lost the slip, i can try to find it) on just 6.5 psi. Point is, tuned well and driven right, turbo Honda's can be formidable. Too bad most of them are stickered up slow bumblebees that think they own the road. But, such is life.... Todd.

Click to expand...

LOL. I know exactly who your talking about. They are both idiots and shouldn't be listened to at all. That "Extreme" GSX tried to tell me he could run with vipers cause his shit is "balls to the wall".. What a tool..

IF you are a Mile up and run a 13 flat, you will run a 12 Flat at sea Level. Give or take but the rule of thumb is about a 20% power lose per 5800Feet neeting you a .8 second lose and slower traps. Turbo cars are better but still sufer as the intake air is hotter.