JF WS6

The stock 28# injectors are good to about 450rwhp, the SVO 30#'ers are good to beyond that for sure. People use them in 500+ RWHP stroker engines. 42# injectors are overkill for a 346 unless it is boosted.

RedHardSupra

iTrader: (1)

i don't know where you got this horsepoop, but if you want to blow up your 5000 dollar engine because you're too cheap to spend 250dollars for injectors, then you can be right all you want

JZ'sTA

iTrader: (23)

He probally gets it from facts. I haven't ran out of injector yet NA and have done 5 or 6 cars that have made between 400-435HP. The 30's work nicely for 470 HP. I did use 42's in my last 2 setup's both making over 470RWHP.
Now when you go FI you run out of injector fast.

JZ'sTA

iTrader: (23)

As far as the loss of power.
Do a leakdown. You could have broke a springs. Maybe a rocker bolt broke off and is causing a huge loss in power.
IMO you should have defentially gained power.
I assume you had the cam checked to make sure you got what you ordered?
Also as said before check you plugs. If it was a vaccuum leak Norris should have seen that as he was tuning, but that could still be the problem.
On stock heads that cam should make more the 410 RWHP.
I doubt the heads are bad if AFR reworked them. If they added new springs and you didn't do some nice heat cycles on them you might have a broken spring as I said before.
The leakdown will be a good place to start. Then if everything checks out with the leakdown, vaccuum leaks and the plugs its time to start tearing the valve covers back off. Good luck and keep us up to date.

JF WS6

How big do you think the T-REX is? 440-450RWHP with stock heads/shortblock.

The reworked heads might be a more likely culprit, although unlikely. The injector size is fine.

If this were me, I'd probably study the graph and see if there are any signs of valve float or valvetrain instability. That would definitely take the HP away. If you don't have stock rockers, I guess you could try putting those back on and see what happens. If everything with your valvetrain geometry seems good, and you know you are getting spark to all the cylinders where does the cam peak at? If it's up real high like 6600+ or so, you might want to try advancing it to move the peak down. You could also look into the MAF as was mentioned if you changed it. It could be a lot of different things. I'd take the valvecovers off and look at your plugs as a first step though as was mentioned.

It definitely isn't easy tracking stuff down like this, good luck! There is definitely something wrong though.

JF WS6

Ford SVO 30# injectors are not stock injectors. They cost like $300 bux, so I don't know what the hell you're talking about.

I made 440RWHP with my old setup with SVO 30# injectors and have plenty of injector left, so I don't know where you get YOUR horsepoop from. There is/was definitely something wrong with your old set up if your 30#ers are maxing out at 360 to the tires..... at least on a LS1. If you're talking about your Supra that's a whole different story with the turbo you CANNOT compare 2 completely different cars like that if that's what you are doing.

Also the LS1 runs at a higher fuel pressure so the 30# SVO's are more accurately somewhere around a mid 30's # injector on a LS1.

ninobrn99

iTrader: (8)

he's not talking about stock injectors. he was refering to the 30#'s and the 42#'s can be had from 220-275. Thats what he's refering to.

bigdsz

iTrader: (1)

It is peaking around 6,500 rpm, no float or anything. Rockers and lifters are stock. This cam is just slightly bigger than the TRex. What I can't understand is why it idles so well, I mean it sound like a pretty big cam, but on the other hand docile if that makes any sense. I put a dial indicator on the spring retainer to verify the lift, so for at least the 2 valves I checked I know the lift was right. Also as stated before it was degreed in. I wondering about the heads also but don't know what it could be. Guys I need some more input!!!

JF WS6

He mentioned something about being too cheap to buy new injectors. As I was stating, they cost like $299. I wouldn't call that being too "cheap" to buy new injectors.

ninobrn99

iTrader: (8)

swap back to the stock heads, dyno and see what your numbers are like and during that time, have the others flow'd

Patrick G

iTrader: (14)

Have you tried killing 1 cylinder at a time? (with a Tech 2 or by pulling a plug wire or injector wire). This might help determine if you have a dead cylinder (which is what I suspect). No way you'd be making peak power at 6500 rpm if you had the cam in wrong or if the springs/valvetrain weren't up to snuff. Look for a dead hole (and pray it's something simple like a bad wire).

ninobrn99

iTrader: (8)

i think he meant in general. most people dont upgrade injectors when they should. your right, 30#'s are expensive, but when you can get green tops for a cheaper price, why wouldnt you?? better to have more than enough than not enough, but this little argument isnt realtive to helping this guy out on what his problem is. Until we can get a log of his duty cycle's then only the tuner knows what its at.

SideStep

I am using the same injectors (SVO 30s)... 450rwhp (SAE) and my duty cycle is 74% at its worst point....

JF WS6

What does it idle at? I recently put a cam bigger than this even (242/250) in my car only weeks ago and although it isn't tuned yet, I don't see it idleing smoothly at all at anything much less than 1K RPM. You sure you got the right cam in there? Did it idle no problem once you fired it up? Mine won't idle for **** unless it's warm, and then it only sometimes finds an idle the way it is right now.

ninobrn99

iTrader: (8)

off topic :how much are tech 2's?

JF WS6

Point taken, but are you saying you think 30's aren't enough? Because they definitely should be for a H/C car.

RedHardSupra

iTrader: (1)

ok, our of curiosity, the people who get so much hp out of your stockers, or svo30s, do you happen by any chance to tune your own cars? how is it tuned? do you tune with IFR tables, or is it a calculated table?

i can post screenshots of how i reached 109% duty cycle on stock 26.4s with a z06 cam and stock headers if you'd like.

also, i'd post a link to some very cheap injectors, but since they're from a nonsponsor i'd get my *** booted. pm me if you're interested.

ninobrn99

iTrader: (8)

no im not saying that. if he said that his duty cycle is 74% at the most, then its not an injector issue, but t/s without that info is difficult, so we throw out a few common things that it could be...

ninobrn99

iTrader: (8)

i think i know which one your refering to

Louis

iTrader: (7)

I need to see the graph.

The injectors are fine.

ANy log files from runs?