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stock injectors capacity

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DSM90AWD said:
From your own profile


You're running 13.6@100 which is ~250WHP. Why would you need more fuel if your stockers can supply 300WHP as you say :confused:

I will concede that 300WHP may be possible on 450s if you're running race gas as your engine can run a much leaner mixture (i.e. less fuel). Though Phil Beers (the quickest 14B guy on stock engine/inj..etc) was 34HP shy of that number on Race Gas.



Joe bucci is the fastest 14b on a stock motor and stock injectors and runs a 11.2 on them.
I dont put alot of faith in all these online calculators.
 
Steve93Talon said:
As for the injector calculations, everyone's wrong. You're forgetting to add 1psi of fuel pressure per psi of boost, for example a base FP of 43 at 20psi gives ya 63psi, and 450s will flow alot more at 63psi than they will at 43 ;)

This is not true. The 1psi of FP rise per pound of boost merely maintains the same pressure differential between the rail and tip of the fuel injector(ie intake manifold). Which means as long as the fuel pump can provide enough fuel pressure, the flow will not change with boost.
 
DSM90AWD said:
Awww.. come on. Don't you want to be known as "That Guy that proved everyone wrong that 450s can support 300WHP" ;)

I wanted to be this guy and I offered a bet to anyone willing to accept it. I would install the 450;s in my car setup to make more and take it to the dyno and do 300whp IF when I did it the people who told me it was "impossible" and a "ludicrous claim" and all other BS to JUST PAY FOR THE DYNO TIME IF I PROVED THEM WRONG. If I lost I just wasted my time and money and WORSE YET WILL BLOW UP according to the doubters. Anyone willing to take this simple bet can either respond here or PM me. The money can be paypaled to a neutral 3rd party and held in escrow and a neutral 4th party from SE PA can come and watch and confirm the results.


Later
 
Steve93Talon said:
As for the injector calculations, everyone's wrong. You're forgetting to add 1psi of fuel pressure per psi of boost, for example a base FP of 43 at 20psi gives ya 63psi, and 450s will flow alot more at 63psi than they will at 43 ;)

Actually the rising rate FPR is meant to keep absolute fuel pressure differential equal at the injector outlet. At an intake pressure of 20psi, the injector has to offset 20psi of pressure so the FPR increases the rail pressure by 20psi. So with a base fuel pressure of 43 and 20psi of boost, the rail pressure will be at 63psi but the effective pressure at the injector tip would be nearer to 43psi.

Think of the analogy of spitting into a 50mph wind.

As for running 12.7, that's quick, but Phil ran 12.0000 on race gas and I still don't see a 300WHP # on pump :dsm:
 
unior said:
what were you using to log DC - pocketlogger always seems way off to me
because 550s will support 450+whp at less than 90% DC without insane fuel pressure

I use a TMO Datalogger to log IPW and RPM and convert to DC% using the formula
((IPW*RPM/60)/2)/1000 which I got from Jeff Lucious' site.

I also posted HERE not long ago that my initial run with my 50-trim on 550s @43 base FP netted me 100%+ DCs > 5500 RP Ms on 20psi boost and 93octane.
20psi netted me 12.85@106mph in my 3300# car so figure I was at about 307WHP as calculated HERE so I cannot possibly see (in my car anyway) supporting an additional 150WHP on pump with 550s.

BTW.. I apologize to the initial poster for this thread's tangent, but think he would agree that the discussion that was brought about is valuable and factual in nature :thumb:
 
you know this entire topic was discussed in plenty of detail just a couple weeks ago

just that some moderator deleted like 3 pages of that informative thread
 
Tons upon tons of Honda guys are taking stock 450cc DSM injectors and making 300+whp on them..

Wouldnt that be accountable that 300whp is doable on DSM 450cc injectors??
 
STHPERFORMANCE said:
Tons upon tons of Honda guys are taking stock 450cc DSM injectors and making 300+whp on them..

Since you've seen these Dyno graphs and are a Vendor, would you recommend 450s to a DSMer whom is looking for 300WHP on PUMP :confused:

BTW.. the HP Rating of the injectors you sell (Precision) is based on the same RC Engineering formula but using a non-turbo's B.S.F.C. (.50)
 
DSM90AWD said:
Since you've seen these Dyno graphs and are a Vendor, would you recommend 450s to a DSMer whom is looking for 300WHP on PUMP :confused:

I am sure you could get 300whp out of a 16g on stock injectors?

Or are you stating 300whp using stock injectors and stock 14b??
 
A rewired 13v-14v 2g fuel pump on pump gas, stock 9.5:1 AFR's will supply enough fuel to support 35lb/min airflow at 15psi. If you had the means to turn your AFR to a more moderate 11:1 it would supporr upto 40lb/min Max at 15psi. Thats Way more then enough for your stock injectors to handle

walbro 255hp @ 15psi, 43bfp, 11.1, pump gas = 72lb/min
walbro 255lp @ 15psi, 43bfp, 11.1, pump gas = 69lb/min
walbro 190 @ 15psi, 43bfp, 11.1, pump gas = 51lb/min

You can't caculate horespower. You never know what Mechanical effency your engine is producing. You can Mathamaticly caculate supported airflow, so you know what is possable . But there are to just to many verables involved to pin point exactly what "you" will get. I'm not saying the math isnt right, and you cant caculater Max avaliable HP based on those verables. Im saying you can not know for sure what your own engine will produce. Unless your just that damn good :cool:

The 450cc 2g injectors @ SBFP, Stock AFR will Support 28.6lb/min airflow on pump gas. If you run SBFP & 11.1:1 (fastest flame speed, and common conservitive #) you'll net 33lb/min. As you can see. So you can see 2g rewired pump is fine untill 16g terittory.

One thing to reamber is when your using an aftermarket fuel pump in excess of 45GPH flow rate on your stock FPR, you'll be starting to overflow your FPR. And you'll need to compensate for that if you have an safc by leaning things out a little more then normal to compensate for that extra pressure in the Fuel system. It's impossable to say how much. It depending intirely on what fuel pump you have, boost your running, AFR's settings and gas your using. Hope that helped some
 
I've seen 237whp out of a turbo G20 on stock nissan 370cc injectors @ 60psi base fp on a very safe tune. I'm sure 300 whp is possible out of 450's, but why risk it?
 
scottsee said:
The 450cc 2g injectors @ BFP, Stock AFR will Support 28.6lb/min airflow on pump gas. If you run BFP @ 11.1:1 (fastest flame speed, and common conservitive #) you'll net 33lb/min. As you can see. So you can see 2g rewired pump is fine untill 16g terittory.
Great info. Do you know if HP ratings of injectors are based on a specific AFR?

Also, at the 11:1 AFT (BFP), 33lb/min equates to ~330HP. So subtract 18% drivetrain loss and we're at 270WHP.

FYI.. I upgraded from 450s to 550s to 660s based on need (high DC%) not formulas. If Joe Blow can run 300WHP with 450s in an XXX car with 60psi BFP, water injection and a standalone capping ignition advance. I will still tell people with 300WHP DSM dreams to pony up for 550s+.

taylorspl said:
but why risk it?
Exactly :dsm:
 
I quoted myself because I want people to realize that this has been said time and again. 300whp on 450's is def feasable. The difference is how well the car is set up to do it. Pump gas and race gas come in to play only due to the cars efficiency. I have personally tuned a DSM that made 500whp on pump gas at ~23psi. MOST people cant make this power on pump gas no matter what injectors they have. IF your setup needs race gas to make 300whp it will need it wether or not you are using 450's or 880's.

Also as far as the timing issues it is SAFER to run 300whp on 450cc injectors than on bigger because you get runaway timing from trying to lean out larger injectors. If you are using the stock sized injector it will always be on the correct map and have no issues with crazy timing advance. Anyone who doesnt think it is possible should feel comfortable with a 60-120 dollar wager to see who is right.

Later

Batty200 said:
I wanted to be this guy and I offered a bet to anyone willing to accept it. I would install the 450;s in my car setup to make more and take it to the dyno and do 300whp IF when I did it the people who told me it was "impossible" and a "ludicrous claim" and all other BS to JUST PAY FOR THE DYNO TIME IF I PROVED THEM WRONG. If I lost I just wasted my time and money and WORSE YET WILL BLOW UP according to the doubters. Anyone willing to take this simple bet can either respond here or PM me. The money can be paypaled to a neutral 3rd party and held in escrow and a neutral 4th party from SE PA can come and watch and confirm the results.


Later
 
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