Hey guys,
a friend of mine is going to have the setup on his 99 cavalier automatic. I read the Sticky about the pre 2ks with the s/c. Hes got injectors and the kit, and i have hpt to set the constant etc. But, does the set up throw any codes without using the 2 bar map sensor? Anything i change when i tune it?
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
nate, you will still need the 2 bar map sensor so the car can see boost
The '99 computer can't read boost, so a 2 bar map won't do any good unless you fake a 2 bar with HPT. All you need to do is change the injector constant and you will be fine. Faking a 2 bar is only needed if you need additional tuning to fine tune the tables.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
Luke Heier wrote:The '99 computer can't read boost, so a 2 bar map won't do any good unless you fake a 2 bar with HPT. All you need to do is change the injector constant and you will be fine. Faking a 2 bar is only needed if you need additional tuning to fine tune the tables.
thanks, learn something new everyday, appreciate not being flamed
Hey, no prob. All those people on here who like to flame is what gives JBO a bad name.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
it's already been said that the 99 ecu cannot read boost, so there are a few ways to accomplish this, faking a 2 bar is one. The other is using an fmu or 1:1 ratio afpr which is usually what most ecu's read boost as anyways. I am personally using an fmu to accomplish this and it has worked excellent for me.
"Horsepower is the Ultimate Accessory"
but if you use the 1 bar map, don't you need to run a check valve in line to the map signal line so you don't throw a code? I think using a 2 bar map and faking a tune would be very benefitial... you could pull timing with pressure (map signal) they all work on 0-5v
HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED
jimmyc99z24 wrote:it's already been said that the 99 ecu cannot read boost, so there are a few ways to accomplish this, faking a 2 bar is one. The other is using an fmu or 1:1 ratio afpr which is usually what most ecu's read boost as anyways. I am personally using an fmu to accomplish this and it has worked excellent for me.
mm... so if I use HPT to change my friends injector constant.. do i still need a FMU? I quickly read shifted's post on how to do a fake 2 bar. But what kind of benefits do you get from that? Cause i don't have time to do lots of fine tunning.
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
If you change the injector constant and get it to where it should be, there will be no need for an FMU anymore. You only need to fake a 2 bar is you want a very fine tune across the board. Usually, you can get away with just changing the injector constant. Faking a 2 bar is NOT required. It all depends on how the car runs after changing the injector constant.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
Ok, where do I start, well, here, there is only one thing in this thread that I see is correct, and that would be that the 99 cannot be reflashed by GM. BUT anyway, GM reflash and "faking a 2 bar tune" are completely different things. The ONLY thing you are doing when you fake a 2 bar is giving yourself the ability to tune ignition (timing advance or retard) while in boost, you arent giving yourself the benefit of "very fine tuning or anything of the like", none of that made sense. Actually, when you fake a 2 bar, you are actually cutting the resolution of the map in half, so really, its the opposite of very fine tuning. Also, by telling the guy that all he needs to do is change the injector constant is first hand telling the kid a good way to blow his motor. What does an injector constant have to do with the amount of air going into the motor. Alpha-N tuning relies on the VE tables to control fuel, not an injector constant. Injector constant is some number that tells the computer how large of injectors the fuel system has so it can send out the correct pulsewidth. Larger injectors would either need lower fuel pressure of if he has HP tuners, a new injector constant. None of that solves the problem of much-needed-fuel while in boost, so, welcome to the VE tables if you have HP tuners, or obviously if not, a FMU to raise the fuel pressure according to the amount of boost.
soi it would be wise to go get a stock fmu or an aftermarket one
14.728 @ 92.14 (65 shot)
Well, if you have HP tuners, use the VE maps to tune. If you dont have it, then you will need an FMU, yes, preferably Begi adjustable unit.
