more from my 99 silverado

juicy · April 11, 2004

i have a 99 silverado 4x4 on 35's

6in fabtech lift

3in performace body lift

i have dual flowmasters

borla headers

air force one intake

hypertech programmer III

and i dont think im getting enough out ot my truck

i tried to race my girlfriend in her ford focus

and she ran neck and neck with me

i was sad.

i know im carrying a lot more weight than hers..

but i dont know what else to add to get more hp

rhilton · April 11, 2004

procharger hands down, or a vortech. around I'm thinking 4500-5000 rpms, you'll be dishing out around 135 extra hp, but if you're not into the high revving boost, look at kenne bell or whipple. A few guys around here have magnacharger and raddix and they also say good things for them.

If a charger is too much money, go with a westers tune, it'll blow your hpp3 out of the water. But you've done about all you can do with add ons, short of a complete computerized fuel injection system with the laptop

Wingnut · April 11, 2004

You probably don't need more horsepower to beat a focus.

You might want to get some shorter gears to compensate for your 35's. Maybe like a 4:56 ratio?

.02

juicy · April 12, 2004

i got 4.56's on that mofo

forgot to list that

i guess my only other option is a that programmer

or a supercharger right?

Wingnut · April 12, 2004

You could go the naturally aspirated route.

You already have a very free flowing exhaust with the headers, and flows...You need to really open up that intake to match. Have a port/polish job done on the heads, put a new cam in it, and go get a custom tune to make use of all that new air.

You can do all that for less than half the price of a new supercharger, and you can get some very significant gains without sacrificing drivetrain reliability.

juicy · April 12, 2004

what do you mean by opening up my intake?

custom tune...?

i thought my HPPIII did that..

ive been reading about that websters tune.. whats that all about?

juicy · April 14, 2004

anyone? wingnut?

rhilton · April 14, 2004

Westers info

Even more westers info

About opening up the intake more

the tune doesn't open up the intake, it provides an advanced spark in the ignition system, which is why you usually have to run 93 octane, because it has a higher pressure before it ignites, and the last thing you want is the gas to ignite before it's ready to.

The stock intake ports and exhaust ports are machined crudely performance wise. Port and polishing the heads make a smoother flow of air, increasing power. A new cam makes the valves lift higher and longer than stock, to allow more air and fuel to go through to the piston. Get the computer tuned to the modifications you made naturally asperated to achieve the benefit of extra power.

I've heard you can increase the compression ration to make more power, but that's far past my knowledge...

juicy · April 22, 2004

wow thanks.. how much am i looking at spending?

Wingnut · April 22, 2004

Depends on how much of the work you are going to do yourself, and what the labor rates are at your local speed shop.

If you pull the intake and heads yourself, and walk them in...It's significantly less. If they pull your intake, and heads, you are looking at quite a bit more.

Pulling them yourself...Probably under a grand. But keep in mind that you will have to get another tune to take advantage of the new air.

99Silver6.0 · April 23, 2004

Juicy,

I know this may sound out of the ordinary.. But have you done any logging with AutoTap at all? To see if you are getting any KR (Knock Retard)? The 99 truck PCM is plagued with a problem in relation to overly sensetive knock sensors. Someting implemented in the PCM of frist run 1999 NBS Silverados picking up false knock. What made me look into the cause was my extremely poor dyno numbers from a while back. Anyways, I found out the knock sensor deal through some users on LS1Tech.com. Parish8 in particular had the same problem with his 99. I was losing 9 degrees of timing due to the funky ass knock sensors. And that 9 degrees was at ANY RPM! So in talks with a few people, I did some logging and in fact I was seeing 9* of KR. There is a remedy for this and it is completely safe. I dont mean to ramble but there seems to be quite a few people with 99 trucks that ran into the same dilemma. I soldered 2 10K ohm resistors in line with each knock sensor and I got back my 9 degrees of timing. Felt like a whole different truck after that!!

Just thought I would throw that out there.

As far as forced induction... R A D I X ! ! ! Then after you do that, give your tranny some more holding power. Throw in billet Intermediate and O/D servos or a TransGo shift kit. Another possibility is a cam. A good cam for your big truck would be the Comp 206/212 .515/.522 112LSA. Great cam for low end and mid range. Has a nice lope to it also and will need a good tune.

juicy · May 2, 2004

Juicy,

I know this may sound out of the ordinary.. But have you done any logging with AutoTap at all? To see if you are getting any KR (Knock Retard)? The 99 truck PCM is plagued with a problem in relation to overly sensetive knock sensors. Someting implemented in the PCM of frist run 1999 NBS Silverados picking up false knock. What made me look into the cause was my extremely poor dyno numbers from a while back. Anyways, I found out the knock sensor deal through some users on LS1Tech.com. Parish8 in particular had the same problem with his 99. I was losing 9 degrees of timing due to the funky ass knock sensors. And that 9 degrees was at ANY RPM! So in talks with a few people, I did some logging and in fact I was seeing 9* of KR. There is a remedy for this and it is completely safe. I dont mean to ramble but there seems to be quite a few people with 99 trucks that ran into the same dilemma. I soldered 2 10K ohm resistors in line with each knock sensor and I got back my 9 degrees of timing. Felt like a whole different truck after that!!

Just thought I would throw that out there.

As far as forced induction... R A D I X ! ! ! Then after you do that, give your tranny some more holding power. Throw in billet Intermediate and O/D servos or a TransGo shift kit. Another possibility is a cam. A good cam for your big truck would be the Comp 206/212 .515/.522 112LSA. Great cam for low end and mid range. Has a nice lope to it also and will need a good tune.

autotap? whats autotap?

99Silver6.0 · May 2, 2004

autotap? whats autotap?

AutoTap is logging software. You run it on a laptop while you are driving and it will take a snapshot and record different aspects of what the truck is doing. It can record ignition timing, knock retard, O2 millivolts, vehicle speed, coolant temps, TPS voltage, long term fuel trims and a whole lot of other vitals. You then take your log files and look at the info they contain. That information is then used to see what your truck is doing so you can adjust things accordingly. There is another progoram called EFI Live that is similar.

Below is a log file of my truck before I put the resistors on the knock sensors. Look how much knock retard I was getting. Look at my ignition timing also, I was barely getting any timing.

juicy · May 3, 2004

autotap? whats autotap?

AutoTap is logging software. You run it on a laptop while you are driving and it will take a snapshot and record different aspects of what the truck is doing. It can record ignition timing, knock retard, O2 millivolts, vehicle speed, coolant temps, TPS voltage, long term fuel trims and a whole lot of other vitals. You then take your log files and look at the info they contain. That information is then used to see what your truck is doing so you can adjust things accordingly. There is another progoram called EFI Live that is similar.

Below is a log file of my truck before I put the resistors on the knock sensors. Look how much knock retard I was getting. Look at my ignition timing also, I was barely getting any timing.

ok so lets say i have this knock retard and my timing is a little off.. what can i do to fix it?. and are the gains noticable?..

i got some big tires... and my truck nealry weighs in a 5000 lbs..

pics are in sig..

will i notice a difference? or are the minor gains?