574.8RWHP with 555cc injectors?

[BRAD D]

Nice car, but can you get 574.8RWHP with 555cc injectors? No NOS,

 

Could he be running 200psi fuel pressure? J/K

 

http://www.zcar.com/month/2003/02/

[Mudge]

12.88 with almost 600 RWHP? Must be damn peaky!

[Lockjaw]

More like traction impaired.

 

Those are good sized turbo's he is running, and I would guess since he has an NOS spoolup kit, that his power doesn't come on until higher up. His MPH is impressive though.

[Scottie-GNZ]

Based on the timeslip, that car is not making anywhere close to what he claims. If you assume it weighs 3600# with driver, the 12.88 @ 122.37 (registers more HP) is about 440rwhp and 530 at the flywheel with a 17% drivetrain loss. I know he had lousy 60' times but if he had what he claims, he would have registered a much higher MPH, like 130. Maybe he did register that number on the dyno, but at the track he lost 100+hp based on his time. Slow 60' times will affect ET but not MPH and sometimes the MPH is higher with a slower 60'. Even if he granny-shifted he would have had a big MPH IF he had his foot to the floor.

 

I am running 50# injs, 525cc, and I am in the 90s% DC range. I suppose if you cranked up the FP with the 555cc injs you could support 570+rwhp.

[Mudge]

Takes 470 RWHP to take a heavy 4th gen Camaro into 10.8@130, naturally aspirated, and if anything has a torque advantage its a Turbo car.

 

574.8 rear hamster power maybe?

[240Z Turbo]

I commented to this guy on Zcar.com. Classic case of 600hp@wheels and 120mph timeslip. It just doesn't JIVE! I make about 474hp@wheels, 100hp less, but was able to run 129.65mph?????? Don't believe the hype!

[BRAD D]

Not that my stock RB turbos can push more than 400rwhp, but I only have 550cc injectors from RC eng. If i upgraded the turbos what hp#'s could I push with the 550's I was thinking 500rwhp?

[Scottie-GNZ]

Here is a formula to use as a rule of thumb:

 

(inj cc / 7) * # of cyls = HP @ 80% DC

 

It is just a rule of thumb and if you run a higher base FP or higher DC%, the HP number can be much higher. However, there is no general rule to apply as to how far you can go. Some engines prefer to run richer and some get mean when they get lean. The leaner the mixture, the less fuel you use but the more danger of detonation. One thing is for sure, the better the fuel management system, the more efficiently you are at maximizing the injs.

[Lockjaw]

Or you can use the simple formula of 1/2 pound of fuel per hour supports 1 horsepower. 550 cc injectors flow 50 pounds per hour, times 6 for six injectors is 300 pounds of fuel, so theoretically, he could get 600 hp out of the injectors.

 

Having said that, that would be at 100 percent duty cycle, and if you want to do that, more power to ya. 480 hp would be more realistic based upon 80 percent duty cycle.

 

He could raise his fuel pressure, my injectors flow 550 cc at 4 bar, but at 2.5 they flow 420cc, so he could have bumped the pressure, and if he used a JWT ECU, he likely did.

 

I also think a better weight for the car is 3700 pounds, with driver. I always thought the ZXTT was 3500 pounds sans driver.

 

Also, in Sports compact car, they built a very stout 300ZXTT and they seemed to think that the car was laying down on the topend because of turbulence at the intakes. So he could have made the power on the dyno, but not made it on the topend running 120.

 

But before someone gets in my case about a rag mag, I am not saying I believe the guy either, just being a devils advocate a little.

 

And I am all for challenging the guy and making him back up his claims, especially when the numbers don't match. If he has a dyno slip, more power to him.

[Guest Zcarsmakemyheadhurt]

The VG30DETT makes great power, but I have never seen a TT get it done in the quarter. These cars just don't transfer. Look at the pic's of that thing at the track spining tire flat as a pancake. One of the reasons I wouldnt buy one.

[Lockjaw]

I think the Cheetah ran 10's, but it had an auto. Maybe really low 11's, but I think 10's.

[Guest z1 performance]

I agree - HP seems way out of range. I put down 405 to the wheels, and ran 124 in the traps, in an S130T

[Scottie-GNZ]

Like Lockjaw, I want to clarify one thing before anyone thinks I am slamming that car or disputing the claim. I clearly stated the reason for my conclusions in BOLD TYPE.

[Lockjaw]

You should really read the article in SCC if you want to know about the turbulence issue. They put some funky panel up there where the pop chargers sit, and they had some funky do clutch that made it hard to launch (7pound flywheel) , so they were launching it at some insane RPM of 7k, and if memory serves, it did not run any better then that car listed. Could be the same.

 

 

So it is conceivable the car makes the power on the dyno, but it doesn't make it in the real world of the track.

[Guest zwhore]

hey, thats my car.

yes it does make that much power, no i cant drag race.

 

if any one want the detail on how i made the power or any qestions post um and i will answer them.

 

first , i sold the car to a guy in tenn. . i owned an performance shop in ohio and owned my own dyno , so i spent countless hours tuning it. i built it as a showcar not a drag racer.

the greddy turbos didnt reach full boost(18.3 psi)untill 4800 rpm. so drag racing wasnt a very good career for the car. even the NOS spoolup kit didnt work the way it was supposed to.

 

anyway, like i said if you have any question post um or better yet email me. and if you have a negitive comment dont bother. i can prove everything about it and hate arguing over the internet with accountants who dont understand the fundamentals of an interal combustion engine.

 

and the fuel psi is 38 at idle and 57 @wot. redline 7950. and it would spin the 285/30/18 kumho v7000's until 4th gear. spanked a 360 modena at only 10psi. took an R-1 till 180 from an 80 mph roll and won first at hot import nights. damn i realy miss it. but the 72 only cost about 1/5 of the money i dumped in to that.

 

the first time i ran it (at 10 psi) i ran a 20.08 @133. i launch with the NOS and it wheel hopped so i let off, then nailed it and the NOS backfired and stalled it. how imbarassing. the best run of 12.5 spun the tires(smoking them actually) untill 4th. i dont use slick even though i have them for it. i feel if its a street car race on street tires.

 

check out the pics i put it of it. i have more too.

http://photos.yahoo.com/bc/cornypoophole/lst?.dir=/car+stuff&.view=t

 

tony

[Guest zwhore]

o, and its funny how everyone assumes everyone eles can drag race.

ever hear of a car not hooking up.? and i always get nervous for some reason and screw up and miss a shift.

its not a red neck camaro or rustang. the z was never designed to drag race. it was ment to out handle just about anything. and it did.

the car at stage 5 did 13.01 @ 110 with a 2.5 60'.

i cant explain it enough, i just cant drag race. the best 60' i ever had was in my 99 gs-t, 2.0 flat. i was damn proud. even in my 86zxt with slick i had a 2.1 60' with a 14flat at 105, intake and turbo back 2.5" exhaust.

 

sorry , but i hate it when people rag on other peoples hard work, just because they dont believe. its called reseach, big ass cams great exhaust and port work.and a few other goodies.(jdm front mount )

[BRAD D]

The main reason I posted this was because of his injector size, I did not think it was possable to get 574.8RWHP from 555cc injectors.

[Guest zwhore]

if you take advantage of everything you can, maximize engine efficincey, you can take the 555's to 600rwhp. its been done.

i was still a little rich on top, but i was going to get the border 850 injector kit, but i had to sell it. i might buy it back if i get the chance. then i can take everyone for a ride.

[Guest jt240z]

Why do the torque and HP lines cross so early?

[TimZ]

Why do the torque and HP lines cross so early?

 

The horsepower and torque scales are different. The lines cross numerically at 5252, like they are supposed to.

 

The rules of thumb stated for injector sizing are based on a Brake Specific Fuel Consumption of 0.5 lb/hr/hp. The BSFC can vary from about 0.4 to about 0.6 depending on the engine.

 

Also, the 80% rule has nothing to do with how much power the injector can ultimately support - it is there to tell how much headroom you should leave yourself when sizing injectors so that you won't go static. The injector should still flow it's rated amount at 100% duty cycle, you just no longer have any control over it. Notice the flat horsepower curve from about 5500rpm on up - there is a very good chance that the injectors had gone static there.

 

The fuel pressure numbers don't quite make sense to me - I am basing my assumptions on 57psi at 7950rpm and previously stated 18.3 psi boost, which gives a base pressure of 38.7 psi. This jives reasonably well with the 38psi number given for idle, assuming he really meant 0 vacuum and not idle.

 

Anyway, since injectors are rated for flow at 43.5psi, running a base pressure of 38psi derates them by about 7%, meaning they would have been performing like 520cc injectors.

 

If the comments in this thread offend you, well - sorry, but you should realize that there are boatloads of bullshit hp claims floating about these days (probably always have been - the internet just makes it more evident), and if you offer up really big numbers to a reasonably educated audience and the details look funny, you are going to get challenged.