Fueling Question

[Norb85]

I was wondering what the stock injector size was for my car. I'm looking to make about 320hp at the wheels and am open to suggestions on what injectors to use. I'm also wondering if I will need to replace the fuel pump with a higher flowing one. I'm assuming I'll need to do both, but I want to be absolutely sure. Like I said, I'm open to any and all suggestions.




Now that my baby runs, I can really plan out what to do with it.

 

[laza101]

You will need both a fuel pump and injectors to make that kind of horsepower reliably, especially on pump gas. 550's may be ok, but you'll be pushing them to make ~320whp - people have hit 117+mph in the quarter with these (pushed to the max on bigger turbos and race gas). 650's will be plenty, maybe too much for that turbo, you MIGHT have troubles with too much timing advance. Note that if you opt for large injectors or more fuel pressure, do your fuel pump research (flow rates/pressures).

I have a vr-4 fuel pump, 16g with supra IC and larger piping, 2.5" exhaust and ported exhaust components. I have some 550's coming in tomorrow, my 510's are over 90% duty cycle at 17psi on pump gas...

 

[Cirus_93TSI]

ur stock injectors are 450cc, they are good for about 250 to the wheels if they are at 100% injector dyty cycle
u should be looking at injecors over 600cc to make 320 whp, u would probally need race gas to push 550s that far

 

[Norb85]

Thanks for the info. How much power are you putting out now laza101?

 

[laza101]

Believe it or not, I've had the car for 5 years and never dyno'ed it or took it to the track! Considering how it runs and the cars I've raced, I'm guessing I have around 300hp at the flywheel right now. Some cars that I AM faster than (some worse than others):

-Mustang GT with mild mods,all years
-mid-90's Camaro Z28 (280hp)
-3000GT VR-4 (older 300hp models)
-supercharged BMW 540i (5psi)

I haven't raced any crazy cars lately, except a 490hp Audi which made me feel like I was in reverse...I want see what it does against C5 Corvette after I install the injectors and tune it. I'm figuring I'll be running about 330+hp@flywheel on race gas.

 

[Norb85]

Nice. I have one more question that might be a little stupid, but don't bag on me for it please. I was wondering if it would be safe to put higher compression pistons in my car with a 16g turbo. I'm looking for information so please give me that and not a hard time.

 

[laza101]

In my opinion, it would be much more worthwhile to raise the boost instead of raising the compression in your car. The first gen cars are perfect for high boost because of their low compression. Raising compression will not let you run the same boost levels easily.
Boost = horsepower, compression = torque. At your power level, switching pistons is waste of money. Put the money into intercooler, piping and injectors and tune it right.

Question: Why are you thinking of raising the compression?

 

[Norb85]

I wasn't really thinking of doing it. I was just curious. Even so, I'm not just looking for horsepower. I'm looking for a good amount of torque too.

 

[Kevin Jewer]

Originally posted by Cirus_93TSI
ur stock injectors are 450cc, they are good for about 250 to the wheels if they are at 100% injector dyty cycle
u should be looking at injecors over 600cc to make 320 whp, u would probally need race gas to push 550s that far

I ran low 12s on stock 450s, and trapped 119 on 660s. Thats about 440 whp. 320 whp is less than 110 mph traps which I did all day on stock injectors (race gas). Am I reading a MachV page here? Also remember once you get up to 660s, youre going to need more than an AFC to lean them out enough on race gas. To the original poster, your best bet for under 400 whp is 550s and a 190. Both will go 11s on race gas. On pump, you are limited to 12s with that setup. If you never plan to run race gas, only pump, go 660s now if you want. Hope that helps.

 

[turboeclipse98]

if you want that kind of power you will definetly going to have to get another fuel pump or aux. pump cause you need fuel pressure to go with boost.