Fuel injectors upgrading

jamesyb · Post by **jamesyb** » Wed Dec 09, 2009 2:11 pm

Here is my story, my son (14) races this 2005 Neon (Saratoga Speedway BC Canada), I have lowered it (changed struts and springs), installed sway bars, jet performance chip (2nd stage), cold air intake and now I want to change the injectors and go with a Walpro fuel pump. This is a stock 2.0 lit engine.

Here's the question...... which injectors would be best 450, 550, 650, 750, 1000. Can you give me an idea I don't even know what the original size is so upgrading is a bit of a guess.

FAC3L3SS · Post by **FAC3L3SS** » Wed Dec 09, 2009 2:13 pm

From what I've read, injectors we use go by pounds. I've seen people talk about 24lb and 30lb injectors. Also, it was proven on here by a member that the JET chips don't work.

What sort of racing does he do? How long has he been doing it? Where do they let him do it, being he's only 14?

n20sxt · Post by **n20sxt** » Wed Dec 09, 2009 2:20 pm

FAC3L3SS wrote:From what I've read, injectors we use go by pounds. I've seen people talk about 24lb and 30lb injectors. Also, it was proven on here by a member that the JET chips don't work.

What sort of racing does he do? How long has he been doing it? Where do they let him do it, being he's only 14?

all injectors can be measured in lbs or cc's, its a very simple conversion

To convert cc / min to lbs. / hr. - Divide by 10.5
To convert lbs. / hr to gal. / hr. - Divide by 6
To convert cc / min to gal. / hr. - Multiply by .015873

Post by **racer12306** » Wed Dec 09, 2009 2:20 pm

Some organizations have a licensing program and allow anyone with a competition license to compete.

With a stock 2.0 you are good to go with the stock injectors. There is no need to upgrade the fuel system at all. You have to do very very significant modifications before bigger injectors are needed.

And ^^^ is correct, the JET "Chip" isn't doing anything for you.

FAC3L3SS: injectors are also measure by cc's. It's just more common for people here to speak in terms of lbs/hr.

FAC3L3SS · Post by **FAC3L3SS** » Wed Dec 09, 2009 2:32 pm

Thank you fellas. I know on the SRTForums they use CC, but on here they use lbs mostly. . . I only knew them by lbs.

turbodudey · Post by **turbodudey** » Wed Dec 09, 2009 2:36 pm

^^^ Agreed

For a stock 2.0L the stock injectors should be fine even with all the bolt on performance mods.

Stock injectors are 200 cc/min or 19 lb/hr, and are good for up to about 150 hp.

If you want/need more fuel a 24 lb/hr (250 cc/min) injector or depending on your HP goals a 30 lb/hr (315 cc/min) injector would be good for up to 175 hp or so.

jamesyb · Post by **jamesyb** » Wed Dec 09, 2009 2:49 pm

FAC3L3SS wrote:From what I've read, injectors we use go by pounds. I've seen people talk about 24lb and 30lb injectors. Also, it was proven on here by a member that the JET chips don't work.

What sort of racing does he do? How long has he been doing it? Where do they let him do it, being he's only 14?

I know the worst investment was the jet performance module but spilt milk and all.

He races at Saratoga Speedway in Black Creek on Vancouver Island. He has been racing for 3 years. He was the mini oval champion in 2007. It is a 3/8 mile circle track and we are competing with mainly imports. Preludes and Celicas, lots of different kinds of cars and most it seems with a better pit crew than me. LOL His car # is 9 He finished way off the pace this year due to a number of reasons not all the cars fault. The best thing I did was change the struts and lowered it with the rear sway bar. Now I want to add camber to the right front 3 degrees will help. Anyone with performance parts that want to help a young racer are more than welcome to PM me and donate to a worthy cause. I am not only the pit crew but also the sponsor....LOL

Adionik · Post by **Adionik** » Wed Dec 09, 2009 3:39 pm

Sounds like a lot of fun. I'd say get him some lower control arm bushings, should help a lot at the track. For fuel right now you'll be fine.

Get him a turbo..hahah

OB · Post by OB » Wed Dec 09, 2009 6:58 pm

Agreed, don't bother with the injectors. Even if you did need them, you would also need a new PCM to tune with. The stock PCM will just adjust the pulse-width of the new injectors to get the AF ratio back to normal. Not to mention the overly rich mixture during open loop operation would be bad news for the engine and catalyst. Zero gains.

If you want a bit more power, consider an intake, header, and a quality muffler. Maybe grab some good spark plugs and wires, and maybe a lighter crank pulley and flywheel. Your best bet is a set of sticky tires and weight reduction.

What are the class rules?

jamesyb · Post by **jamesyb** » Wed Dec 09, 2009 7:27 pm

Well the rules are....you are supposed to run non modified cars. But as we all know rules are to be broken or at least bent. One thing to remember is there is no cat or exhaust from where the cat used to be except for a straight pipe running out the side. No turbo's no supercharges and no race products such as headers and slicks. It limits what can be done but they don't tech the cars too closely. We can get away with not to noticable improvments. I will do the energy bushings on the front end and probably the motor mounts. I have order the camber adjustments. Also the tires have to be 60 series and higher, no slicks or racing rubber. I thought the injectors might help if I doubled the cc's from 200 to 440 or 19lbs to about 40. I see what everyone is saying that it would be a waste. I do however run a mixture of aviation and premium gas.50/50. Not in the rule book...LOL So with this in mind all suggestion are both welcome and appreciated.

Fuzzyneon · Post by **Fuzzyneon** » Wed Dec 09, 2009 7:44 pm

i wouldnt mess with fuel delivery system
just
camber
what sway bars do you have now?
what tires?
im sure there's alot more but im not a track pro

Post by **racer12306** » Wed Dec 09, 2009 7:54 pm

All you will do with bigger injectors is wash down the cylinders with unburned fuel. The computer will try to pull fuel, but that would be a lot of pull.

All you are gaining with running avgas is the oxygenation. There is no benefit from the added octane, it may actually be negating the benefit of oxygenation.

Things that come to mind that are more like OEM would be:

* a 1995 SOHC cam - couple HP gain, has a mopar part number
* a 2001-2004 Neon R/T exhaust manifold (it's more like a header, flows better than a normal manifold) has a mopar part number
* summer only ultra high performance tires in 185/60/15, which may not be available.
* don't know if you could get away with solid motor mounts or inserts.
* if you can do aftermarket wheels you could find a set of super lightweight 15" wheels

I have a set of motor mount inserts that I am pretty sure are prothane race inserts, they may be street inserts. All you would need is two big washers to make them work.

If you want them they can be yours for the cost of shipping. No one here wants them and I'd rather they go to a good cause.

OB · Post by OB » Wed Dec 09, 2009 7:56 pm

Without a proper PCM tune, running special fuel isn't doing anything for you. You're probably not getting a proper burn and might even lose power. Going by what you said about bending the rules, I'll recommend weight reduction even more. A lot of it can be done without any obvious visual changes. Remove the spare tire/jack, remove the wiper washer reservoir and motor, delete your AC system etc.

Post by **racer12306** » Wed Dec 09, 2009 7:58 pm

Derek, avgas is oxygenated so you will get a more efficient burn in a car since the point is to provide oxygen at altitudes so the engine actually runs right and has good power.

Post by **occasional demons** » Wed Dec 09, 2009 8:09 pm

jamesyb wrote: I do however run a mixture of aviation and premium gas.50/50. Not in the rule book...LOL So with this in mind all suggestion are both welcome and appreciated.

With the 9.3:1 compression ratio, you are prolly loosing power with that octane rating. By the time it gets burning to it's maximum efficiency, the piston is too low in the bore. Higher octane = slower burning. Without the C.R. and timing advance to utilize the octane, it is fairly pointless. I would not go any more than 89 with a basically stock NGC engine. You could use the R/T piston assy's and still technically be stock. That would at least get you to 9.8:1. Then you could make better use of the fuel. E85 can also be mixed. I have added up to 2.5 gallons to my tank with both 89 and 93 octane. This adds more seat of the pants power than the UDP I just removed, ever had a wet dream about. I have an '02 R/T pcm to make use of the extra octane tho. Not too sure how much advance an '05 pcm would run with, if it had the C.R. and some good fuel.

You could also do the half shaft mod to the throttle body, and sand off the dovetail from the throttle plate. Those two items would be barely noticeable to an inspection.

Half shaft mod:
viewtopic.php?t=14771

jamesyb · Post by **jamesyb** » Wed Dec 09, 2009 8:14 pm

Just so you know I have stripped the car down to what is legal, in this class they want the dash in with a working radio so as to be able to communicate with the cars. This is probably wishful thinking on the tracks part. But it has been stripped to the dash and drivers seat only. Roll cage and side protection bars added. Running 205 60 15's The original sway bar up front and a ACR sway bar off a 2003 in the rear. I did install strut tower bars.

OB · Post by OB » Wed Dec 09, 2009 8:15 pm

^Bingo OD.

Rather than go too in depth with the throttle body mod, I just shaved the screws flush with the cam and ported the inlet and outlet mildly. Made a noticeable difference in response and actually sounds a bit different as well.

Post by **racer12306** » Wed Dec 09, 2009 8:17 pm

If you go back to 185/60/15 the car will be quicker.

You are killing the effective gearing on the car. Yes, you will have a 20mm narrower section width, but a good tire will make up for it.

What octane level is the avgas?

Post by **occasional demons** » Wed Dec 09, 2009 8:20 pm

Another tire size if you have some 14" wheels is 195/60R14.

These will be a little shorter, and give you a bit of a gear ratio boost. The aluminum oem 14" rims are 1/2 " wider than steelies. Any of the DCX eighties through ninties smaller FWD cars have 14's that will bolt on. I think the LH cars have a bigger bolt pattern, and you wouldn't find 14's on those anyways. Basically anything that had 14's will fit. I'm sure there are other makes, but I can't promise anything there.

jamesyb · Post by **jamesyb** » Wed Dec 09, 2009 8:22 pm

I have an '02 R/T pcm to make use of the extra octane tho. Not too sure how much advance an '05 pcm would run with, if it had the C.R. and some good fuel.

Any chance of selling that PCM?

Post by **occasional demons** » Wed Dec 09, 2009 8:26 pm

An '02 PCM will not work in any neon '03 - up.

'04 is the last year that R/T's were made, and IDK if an '04 will work in an '05.

OB · Post by OB » Wed Dec 09, 2009 8:28 pm

^Correct. The crank reluctor wheel is different.

Post by **occasional demons** » Wed Dec 09, 2009 8:33 pm

OB wrote:^Correct. The crank reluctor wheel is different.

As well is the block. The PCM even is wired differently (two connectors vs four).

And as for the PCM, no I have no interest in selling it. How often does one get lucky enough to get a SKIM PCM to run in a non SKIM car?

My only fear is that one day it will realize what is going on, and lock my ass down.