Hi, I have a 98 sunfire and Im looking to do the gm supercharger swap. Beyond getting the larger fuel pump and injectors Id also like to get a stand alone fuel management system. Which system would be the best suited for this application. The sunfire is a 2.4 5 speed bonestock. Id like to keep it this way beyond modifying the fuel system.

well i can tell you right now you wont need to do all those fuel mods if all your planning is running the M45. i could see the injectors though, as your going to need to get larger low impedence ones anyways.

you'll never make the kinda power that requires those fuel mods (with the M45 that the GM kit for the 2.4 utilizes).

i was under the impression that the factory gm computer was not so great for accepting boost. I would like to install the supercharger on the the 98 and still have a fully functional daily driver. I would like to have it the best running it can be. Would a stand alone fuel management unit not be the way to go on a 98 ?
Im looking for ease of installation and reliability money isn't really an issue.

ok, i think i mis-understood you. you want to use a fuel managment unit (FMU) correct? if so, then yes definatly.. that will work fine. i thought you meant a stand alone computing unit lol

you need something that will raise fuel pressure relative to boost pressure, which an FMU will do for you. its not as efficent as using the stock computer to do it the right way, but you do not have that option easily availble to you on your 98. you cannot do the re-flash from the kit on your 98 computer, only on a 2000-2002 computer.

and as for the best running it can be, get yourself the option of either doing an HP Tuner tune yourself, or having somebody or a shop do it for you. personally, i would try and find somebody on here willing to give out there pre-00 HPT M45 tune and do your VCM for you.

Im planning on doing the supercharger kit this august when I have holidays for 3 weeks. Which would be more then enough time to install and tune it. Im new to the boards and the lingo. What do you mean by the "pre-00 HPT M45 tune and what does that stand for ? And Im assuming the VCM means the cars computer. Im a geek not so much a mechanic but I did have a 89 5.0 mustang way back in the day,required lots of fixing all the time. What size of injectors and fuel pump would you recommend for the stock w/supercharger application ?

you can run the stock fuel pump fine, im running the 2.6" and high 13's with no problems. Right off the bat your gonna be running high 14 sec range, once you start making the pulley size smaller thats when your gonna need more fuel and this and that. Buy HPT (hp tuners software) because that is a 100% plug into your OBD2 port and laptop tune, no wiring or anything.

ok, ill explain things a little better for you.

the gm supercharger kit for the 2.4 twin cam was designed for use with the 2000-2002 2.4's. it utilizes a fairly small supercharger, the M45. when you bolt the kit on the car, the stock 2.8" pulley provides the car with 4.5psi of boost. when you buy the kit you get a voucher deal you take down to the gm dealership when the install is completed with your car and they 're-tune' your computer so that it will then read the boost the supercharger has created and adjust the fuel pressure accordingly to let the car run properly.

unfortunately the older (96-98) computers, or 'VCM's cannot accept this re-tune, or as we call it, 're-flash'. its also not a simple matter of just swapping the VCM's around to work either, there is more involved with doing that, but you CAN do it.

HPT, or 'HP Tuners' is what we can use to tune our own cars for performance, its not a simple plug in and go thing like you see for the newer mustangs, f-body's and pick-ups and stuff get to use. its a lot more complicated than that, although you can just plug it into your OBD-2 port (located under the dash on your driver's side). but you need to have a computer to do the tuning, which you can do right in your driver's seat. -check out the tuning forum for more information on this.

Thanks for the info.

So Pretty Much for my stock 98 sunfire but with supercharger application I will need. I don't want more then 4.5-5lbs of boost anyways. But I don't wanna blow my engine either.

The Supercharger
2000 Starter
EGR Blockoff plate.
EGR Emulator?
Adjustable Fuel Pressure regulator
Cartech Fuel Control module
One step colder plugs
Wideband 02 Sensor

And I keep my stock injectors and fuel pump ??
Would I need to use HP tuners ? Or is the cartech fuel control module and wideband 02 sensor enough ?

A wideband is a good idea regardless of how you control the fuel. Upgraded fuel pump is not needed



FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

No, don't keep your stock injectors, they're not sufficient. Fuel pump, yes, it's fine.




14.330 @ 96.37mph

HP Tuners is expensive dude. almost as much as the supercharger damn to bad you couldn't get the re-flash

Jacob Smith wrote:HP Tuners is expensive dude. almost as much as the supercharger damn to bad you couldn't get the re-flash

He could always find someone close to him with HP tuners and have them tune his car!



FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

Jacob Smith wrote:HP Tuners is expensive dude. almost as much as the supercharger damn to bad you couldn't get the re-flash

~~shakes head~~ No
HPTuners can be used to removed the EGR code from the computer so you do not need to worry about the EGR sim, and finer control over fuel.
HPT $700
M45 $1400ish



PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

thanks for all the replies

Ill attempt to look for someone in my area with Hp tuners when the time comes. What size of injectors would you recommend ?

the kit comes with 310cc injectors, so i would recommend getting at least those if you plan on running the stock pulley on the s/c.

you can always get a little bit bigger if you would like though. i would bet it would be fine to run 380-440's.

Quote:

HPTuners can be used to removed the EGR code from the computer so you do not need to worry about the EGR sim, and finer control over fuel.
HPT $700
M45 $1400ish

well ok the "kit" is 1400 but you can find a m45 for like 700-1000 used or if you figure the price of the m45 in the kit is roughly 1000 and the other goodies are probably 400

The egr needs to blocked in the rear and the front of the head right?

Maken Waves wrote:The egr needs to blocked in the rear and the front of the head right?

gm makes a block off plate that you can bolt in place of the EGR on the head. it costs under $10. or you can get a 99.5-02 gasket that does not have the egr channel through it.

however, you CAN do either or even both if it fancy's you.

Quote:

The egr needs to blocked in the rear

Where in there rear and what is used to block it off?

The 00-02 exhaust manifold gasket blocks it off in the rear. That is how they block it off from the factory on the 00-02.



FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

yep you are on the right track.


I ran the GM s/c on my 96 z with a 2k motor (only internal mod was seceret cams). I was one of the first few people to do this pre 2000 gm s/c thing 4-5 years ago.

My fuel mods were Walbro 255 pump(pile of crap under half tank)
Cartech FMU, Stock FPR, and stock injectors(well lower mileage 98z24 injectors). I also ran a coolingmist water/meth injection set up with a M4 nozzle that came on at 2psi. That water/meth made a huge improvement to the car. I ran like that for 15k miles(no tuning what so ever) , and i cleared my EGR CEL each time i started the car.. Plugs looked fine, car ran like stock, 30mpg and pulled pretty hard for 5 psi, and i had a 62mm t/b, isuzuperformance header/2.5inch exhuast, 9lb spec flywheel/act clutch and all poly mounts and some other crap.



If i had to do this all over again with the s/c and had a car that HP tuners would work on(didnt work on 96) i would run the stock fuel pump, a inline fuel pump(dont have to deal with the fuel cut issues of ghetto rigging a intank pump), 320 cc injectors, adjustable FMU and Hp tuners and mess around with the water/meth injection and all the bolt on mods then look into a smaller s/c pulley.


good luck