Hello all, I've been gathering all the parts for a 100 shot on my 04 2.2 eco cavy. So I decided to check my fuel pressure before buying the rest of my equipment and I'm reading 55-60 psi at idle also it only drops to around 50-52 psi when I force vacuum the fuel regulator.
To my understanding our cars stock are suppose to run around 45psi and I'm the third owner of this car so I think the fuel pump maybe out of an s-10 or just aftermarket but I'm not sure.
Also the car has always preformed much better then any other eco i've raced eg: saturn l200, another 04 cavy, and a 02 cavy.
I know i have to fuel pressure to run nitrous but i'm also considering it may have aftermarket cams in it too and am not sure how to tell without measuring the lobes and tearing out the head.
You guys think a dyno run would let on to any work that was done before me and if so what does a stock cavy generally put down at the wheels, 120hp or so is what i'm guessing.
My big question is should i just run what i got or still get a new s-10 pump and if the dyno leads to the possibility of cams is there anything i should know before the nitrous like needing a tune or anything else.
Also a little off topic but it is an auto and i wanted to know if it's worth the money for a shift kit, it's only $70 or so but does it really make that much of a difference especially with the nitrous and would i need it if I decided to get it tuned, can they program the new shift points and pressure?
Thanks a lot I need to get this car going to win a bet against a stock 00 mustang gt that only gets me on the half end of the track.
Any input is appreciated.

Wow. Lots of questions! I'll see if I can knock em out one at a time for you. lol

1- 100 shot on a stock L61? You'd be on the ragged edge of what those rods can take. One mistake in tuning or a fail in any part of your system and the rods (at the very least) are history.

2- Your fuel pressure numbers sound exactly right. I run the same numbers and my pump and regulator are stock. 45 psi is the lowest pressure I'd accept with these engines. At that point you should expect your fuel pump to go at any time.

3- Easiest way to tell if the cams are aftermarket is ask previous owners. lol. You could also take the valve cover off and you'd be able to tell from the compression of the valve cover to the head if the valve cover has ever been off. But, not really science there. Possibility to be wrong.What's your idle? Most aftermarket cams have problems idling below 1k-1200 rpm.

4- A trip to the dyno would help to at least determine a baseline. Most stock (dead stock from factory) Ecos are putting down 128-132 whp. Yeah GM! 140 crank HP?? Not even.

5- Forget any other fuel pumps other than a Racetronix in tank. There's a thread on this site (and other sites) that explains how to do a slight modification and use it. That pump will handle almost any mod you're going to do. If you need more fuel than that you'd be using a $1k fuel pump. Don't forget to really get more fuel you'll need new injectors.

6- You need to somehow retard the timing 1 to 1 1/2 degrees for every 25 hp worth of nitrous you add whether that's with HPT, stand alone, or a MSD retard box.

7- The shift kits are a nice addition for you auto guys, but since you need to change timing and would benefit from being able to change your fuel maps HPT would be your best option. You can change timing, fuel, shift firmness, etc, etc with it.

8- Winning that bet with that Stang will be tough with just a 75-90 shot of nitrous and a tune unless he's a bad driver. It is possible though.

damn you eddie, i finally had some answers instead of questions


i will add one thing though, the shift kit imho opinion is worth it, and it should'nt be 70 bucks, i got mine for 35 from aplusperformance
but ttr has there's for like 40 even i think.

hp of course as eddie pointed out would be a better option, but unless you know someone that can do it for you, it's a little on the pricey side.




on a side note, u really think an auto eco is puttin 128hp to the wheels? i'd be impressed if they did. i figured it'd b closer to what the op said like 120 give or take a few.


Edited 1 time(s). Last edited Monday, December 28, 2009 3:57 PM

I've seen dyno sheets to at least 5 different Ecos from stock off the floor to just an intake. Tis very true. GM has a habit of fluffing numbers with the Eco family by low balling. They didn't get caught until a bunch of SS/SC guys started modifying their cars and ran to the dyno to get baseline numbers. The numbers GM put out were supposed to be crank rated numbers but all Ecos were putting out numbers so close to the factory numbers people figured out they were fibbing. That or our drivetrains only have about a 5% loss and that'd be the most efficient trans in the world if that was true.

I would not worry about the rods, but ringlands, if your tuning is not right. The rods have been proven to hold to 300crank hp.



FU Tuning

Actually they were proven to just 280 chp by Gm. they all shattered @ the same time. That's the reason why the build book says to Stay at 250