Little info on this race here. Civic was at 8psi. which is his low boost. t/a was supposed to honk 3 times. but the t/a punched on the second honk here is the

RACE!

I can also show you it running an 11 sec z06 too if you like. and a 650hp Supra getting wasted by it.

GSR vs R6

cammed Ls1 z28 vs civic

that same peaky 522 hp GSR on that site would destroy most fbodies in my races (street).. would not do as well in your races.(drag strip) its whatever you like.

 

^that didn't prove anything, but a higher hp car beating others.

IF you want to adress the powerband issue, you need a 522hp car with equal gearing and weight, on a 4 cyl and one a 8 cyl and then we'd see the difference.

the main weapon is low weight, not power the engine is still Pretty bad.

the Street/Strip thing, just shows that the average domestic guys has his gears closer and the avg import highway racer has highway gears.

give that trans am that 522hp engine and give that integra that ls1 with a 5psi on a t76 (still not peaky) and whichever has the lower weight wins.

by the same token, at undergroundracing.com you can see a trans am giving up 200 pounds to a lighter viper + 150hp and STILL taking that *** out in both street AND strip. That's a powerband.

 

Too bad the only car that was doing all the as$kicking was the supra on racegas. Also, its a far from what this thread is discussing. I thought we were talking about peaky turbo 4 cylinders not I6 Supra's? I really liked how those H&C LS1s couldn't hang with that one supra, but that 383 LT1 could pull on him

 

that wont prove anything. if everything is equal then obviously the cars are gonna run equal.

5psi on a T76 wont make very much power. so that arguement is null. if you wanted to get even more technical, this "put this engine in this car with these mods and blah blah blah" further negates it.

why cant you people face it? a 350whp teg will put LENGTHS on a 350rwhp or hell even 400rwhp ls1. thats fact. and as you go up in power from there the teg or civic will only get that much faster. whats to argue about that? the fact that your making a grocery getter fast? what about impalas? chevelles? malibus? novas? hell what about lightnings? srt10 rams? silverado ss'? those are all vehicles that serve a different purpose yet can be made VERY fast. who gives a sh*t what the cars original purpose was? if you got beat by in then you got beat. MAN UP and admit it. stop making BS excuses. :blah:

 

this may have been said already but has anyone noticed that on the "timeslips" page, the fastest car listed is an LS1 camaro...

 

no its not. its the QUICKEST not the FASTEST.

 

NO MR GENIUS, we're talknig about peaky Powerbands, compared to flat torque curves.

a 522 PEAK hp car, can get taken out by a 520 PEAK hp, the one with the better torque will have the better AVG hp what's 520hp at 9k rpm if you have nothing at 4krpm? And that will prove about superior powerbands

that's my point it doesn't need that much hp because of its avg hp, just like a 460hp f-bod can go 10s. but a 460hp say....300zx is hardly there even WITH the lower weight.

as far as the t76 not making power at 5 psi..on WHAT engine exactly..it all depends on what engine.

using this equation you understand better.

Of known dyno runs the lowest efficinecy with piston turbo engines is 0.52hp/CID psi and the maximum is 77hp/CID psi.

now let's say you have a 454 chevy and a supra 2jz engine both at 5 psi.

454 chevy

0.052 X 454 X (5 +14.7)= 465 hp (minimum)

.077 X 454 X (5 + 14.7)= 688 hp (maximum)

3.0 liter Supra

0.052 X 183 X (5 + 14.7)= 187hp (minimum)

0.077 X 183 X (5 + 14.7)= 277.5hp (maximum) (as we know by now the supra uses 2 turbos and more than 5 psi to reach it's STOCK power, no wonder)


this shows you that at 5 psi of boost the LEAST a turbo 454 should make is 465 IF it had horrible efficiency, and t76 wouldn't be THAT small for a 454. the maximum possible out of 5 psi would be 688hp, 5 psi SOUNDED like nothing right? wrong. turbos are displacement ****** too.

explain to me why a 1000hp supra runs 9.81s (exvitermini.com, home of the 7 second DR tire skyline) and a 460hp camaro will brake in to the high 10s WEIGhING MORE.

i've seen 350rwhp second gen rx-7s in the 11s (2600 pounds AND RWD unlike gay FWD of the teg) and 450rwhp LS1 rx-7s runnning 9s. why? 200 pounds of torque difference that's why.

throw 10k at an integra and it's main advantage is weight not the engine.


as far as "the street" i'm tired of seeing 4.10 geared ls1s lose to highway geared cars already spooled up.

 

Dyno #'s are an indication of how a car should run if read properly.

Just to many times people simply just want PEAK #'s and then bs on how bad their cars SHOULD be.

My old combo in my Z28 made 359/450 STD on a dynojet. Figure the weight was 3600 lbs and it ran a best of 11.751@115.96 MPH in ok weather. Do the math...as others mentioned, under the curve, it made mucho rwtq and it ran well.

My 03 Lightning made 378/445 STD ona dynojet. Weighs around with me I figure 4850 lbs and ran a best of 13.582@102.27 in ok weather. Again, do the math and consider the horrible aerodynamics when compared to most race cars now a days.

Any shop that bases everything off of dyno #'s I question. If you put a set of 3.73's in place of a 3.23 geared car, you lose rwhp, yet the dyno time is a few seconds less.

 

i guess Mr. GENIUS i guess you missed the part of me showing dyno charts of a prelude with a very flat hp and torque band.

if your car is GEARED properly it wont matter if you make peak at 4500 or 8500 rpms

i wont bother with the rest except for the times. times in relation to horsepower really dont mean much to me. what does matter to me in relation to hp is trap speeds which you so thoughtlessly forgot to mention. that supra with 1000 hp runnin gin the 9s is doing it at close to 170mph isnt it? i remember seeing a video of a 9 second supra and it was trapping around there. yet that fbody is prolly trapping closer to 140 isnt it? so convient that you leave the most important part out.

 

very flat compared to what, are you gonna show me one making gobs of torque like a 350? sorry

what if both cars are geared properly...AVG hp still won't be the same and it will still make a difference, that's like saying "what if it has better drag co-effcient".
those usually come in handy as a side comment when

a) car runs a dissapointing time
b) car is not as quick

yup that car is trapping 170-ish or more, i don't see that as some sort of achievement though, when you're seeing some else's tail lights that you shouldn't. Otherwise they wouldn't have timers just mph.

on the other hand you have a 3600 pound convertible trans am, with a supercharger running 8.50s at 163 mph with 100hp less and hundreds of pounds more let a lone drag. that 173mph trap of the supra is not so special anymore, it just makes that run seem that much worst. that was a 9.81 on a track only sponsored car.

 

On what planet does horsepower get calculated by psi??

excal its cfm that gets calculated

its (CID x RPM) / 3456 = CFM

rpms play a very important role in power output.

here's an example of a B16:
(97Ci x 8000) / 3456 = 225CFM

of course, if your engine is bored or stroked, you will have to compensate the CID.

the engine will flow 225CFM at 100% volumetric effeciency (VE). great, in a perfect world. actually VE is about 80-90%. so you'll need to adjust to the VE. 85% is a good number to work with. so addjust your CFM to 191CFM

next up is the pressure ratio. the pressure ratio is basically the pressure of the air going into the turbo in comparison to the pressure coming out. unless you are running sequential turbos, the inlet pressure will be the atmospheric pressure, which is an average of 14.7. so if you want 12psi, here's the formula:
(12 + 14.7) / 14.7 = 1.82:1

now you need the temperature rise. as the compressor compresses the air, it will raise the temperature. there is a formula to figure that rise! there is an ideal temperature rise to where the rise is equivelant to the amount of work it takes to compress the air. here's the formula!
T2 = T1 (P2 ÷ P1)0.283

confused yet? of course not! but lets break it down with some back spins and stuff.

T2 = Outlet Temperature in °R
T1 = Inlet Temperature in °R
°R = °F + 460
P1 = Inlet Pressure Absolute
P2 = Outlet Pressure Absolute

easier now huh?

assuming it's 80º outside and we're shooting for 12psi, your inlet temperature (T1) = 80º + 460 = 540ºR

the P1 inlet pressure will be atmospheric in our case and the P2 outlet pressure will be 12psi. atmospheric pressure is about 14.7 psi (as mentioned earlier), so the inlet pressure will be 14.7 psi, to figure the outlet pressure add the boost pressure to the inlet pressure.
P2 = 14.7 + 12 = 26.7 psi

we now have everything we need to figure out the ideal outlet temperature. now take this info into our original formula ( T2 = T1 (P2 ÷ P1)0.283 ) to figure out T2:
T2 = 540ºR(26.7 ÷ 14.7)0.283 = 676ºR

676ºR = 216ºF = ideal oulet temperature. that's a 136º temperature rise.

once again, in a perfect world, these formulas work grear. unfortunately, there's our old friend adiabetic effeciency (AE). a 136ºF temperature rise is at 100% AE. AE of the compressor is usually 65-75%. so you would use 70% for average. so to figure out the actual temperature rise from the ideal temperature rise, you can use this:
Ideal Outlet Temperature Rise ÷ AE = Actual Outlet Temperature Rise

so, 136º ÷ .7 = 194º

then you add the actual temperature rise to the intake temperature (80º) = 274º

now you can figure out your density ratio! as the air is heated, it expands and increases the volume and flow. to compare the inlet and outlet flow, you must know the density ratio. the formula for that is:
(Inlet °R ÷ Outlet °R) × (Outlet Pressure ÷ Inlet Pressure) = Density Ratio

ok, so our example formula would be:
(540ºR ÷ 676ºR) × (26.7 ÷ 14.7) = 1.46 Density Ratio

with all this crap, you can figure out what the actual inlet flow is in CFM. to do this, use this:

Outlet CFM × Density Ratio = Actual Inlet CFM

so!

225CFM × 1.46 = 328.5CFM

that's a 31% increase in CFM, which is a potential for 31% increase in power. ei, 160hp = 209.6hp. of course, that number is directly effected by intercooler, downpipe, exhaust, fuel flow, etc.

so now you know you need about 328.5CFM to reach your target of 12psi, you now can find compressor maps for different turbos to select the compressor that would best suit your needs. some maps are in CFM, and some maps are in lbs/min. to convert CFM to lbs/min, you would multiply CFM x .069.


Saying a 454 or 2jz will make a minimum of xxx hp or maximum of xxx hp with "xpsi" without paying attention to flow, temperature, VE, Rpms, ignition ttiming, fuel octane, etc etc is very incorrect.