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help! I have date with 3 ricers tomorrow and the car is still not running right.

U

UB2 SLOW

Guest
Okay, I agreed to race three ricers at the track tomorrow. They were bad mouthing Vettes. The problem is my car is still no running right after the mods were put on.This is what I have done. LT4 hotcam, LT4 heads, stage II port and polish, underdrive pulley, yank 2800, 3.73 gears, 58 mm throttle body, Ed Wright programming. LT4 intake, Hooker Shorties, 8mm wires. The car is sluggish under 2000 rpms and it does not down shift when floored, it just accelerates.
 
Joined
May 29, 2002
Messages
8,652
Location
Missoura Ozarks
Corvette
2012 💯 4LT GS Roadster
Tell the Rice Boys 2 Wait !!!!!!!!!!!!!!!!!

Tell the boys u have to finish your mods, if they don't like that 2 Bad !

Hey, u don't want rice n your face :upthumbs
 
F

Fiddler's Gold

Guest
I agree.

You can only shove a rice bowl down their jaws & quiet their Asian-styling attacks if you can out perform them - fair and square. I would say, if you ain't got the Chevy purring then stay the heck away from the pressure cooker. :) Some of them soys carry a hefty bit of salt if you know what I mean ;)

Fiddler
 

compyelc4

Well-known member
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May 1, 2002
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607
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Dayton, Ohio
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'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
I would not lower myself to that level. I had one of those slime-green geek machines challenge me today at a light. I looked right into his eyes and laughed my _ss off. He got the message really well..........and I was cool as I cruised off.
 
D

DkBG

Guest
If you race these guys 50 times and beat them 49 , the only one they'll remember is that one ! Don't race till your ready !!! Cliff
 

rdgfx3

Well-known member
Joined
Jul 25, 2001
Messages
202
Location
Rowlett,TX.
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2008 Silver Coupe
LT4 hotcam, LT4 heads, stage II port and polish, underdrive pulley, yank 2800, 3.73 gears, 58 mm throttle body, Ed Wright programming. LT4 intake, Hooker Shorties, 8mm wire

I can't believe I am reading this.You should beat them with a stock engine with a bad miss on a cylinder.Especially with those 3.73's
What are they driving that skeeres ya?
The car is sluggish under 2000 rpms and it does not down shift when floored, it just accelerates.
Bet you it's the throttle valve cable that needs adjusting.Easy adjustment.

Adjust that and you'll be ready.EASY
 

c4c5specialist

Technical Advisor
Joined
May 29, 2001
Messages
3,682
Location
New Haven, Ct. USA
Corvette
Nope, but someday.
HI there,
A few things please.
Your Hot cam actually will produce less torque below 2300 rpm than a stock LT4, or LT1 for that matter. That, in conjunction with the head modifications, will produce a lower torque level below 2300.
Also, automatics, even with stall converters, and the gears, do NOT take well to high lift cams.
Your automatic, is controlled by electronics, including shift points, line pressure, and the like.
If I were a betting man, I would suggest looking at your throttle position sensor readings, in conjunction with manifold air pressure, and mass air flow readings.
You may be missing something that is so slight, you will NOT set a code, based on the revised programming.
Just a few thoughts, YoursinCorvette, c4c5:hb
 

rdgfx3

Well-known member
Joined
Jul 25, 2001
Messages
202
Location
Rowlett,TX.
Corvette
2008 Silver Coupe
Oy!
Forgot about the electronically controlled tranny system.My bad.
 
Joined
Jun 20, 2002
Messages
2,509
Location
Tallahassee, FL
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none right now :(
how is everything above 2 grand? does it feel like it is running right? The LT4 hotcam really kills low end power... with 6-speed it actually makes the car harder to drive in normal conditions... it takes more throttle to get going anywhere... this is the biggest reason I haven't done it to my vette... after all, the LT4 cam by itself is pretty in-expensive... I figure I use from idle to 2000 rpm 95% of the time, so that is where i will put my money towards.
 
U

UB2 SLOW

Guest
Everything above 2300 is pretty good. I still dont get that kick in the pants feel when I downshift like I did when it was stock. I just raised the fuel pressure again. This time I went from 41 to 46. It does seem to be a little more responsive. I am going to the Dyno tonight prior to the track and see if I can tune it a little better.

As far as the cable, 94-up dont have the TV cable. I keep forgetting that one myself.

I am now getting a IAC code P0506 "Idle Air Control System RPM Lower Than Expected" Any clues on this on?

I am still going to try the track tonight. The fastest one of the Ricers can turn a 12.8. I saw him at the track one night. These are the guys who said my car sounded like #$%@ and that Vettes are over rated and the V-8 pushrod was a relic. They also said that Honda's and Acura's where the future. You can see why I got to show up tonight. Even if the car is not 100%.
 
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Tallahassee, FL
Corvette
none right now :(
When you tune your fuel pressure, the actual pressure does not matter.... you need to tune by air/fuel ratio, otherwise, if the computer senses any kind of too rich fuel pressure, it will shorten the injector pulse... what you wind up with is an injector that feeds the same amount of gas to the engine, but with the higher pressure and shorter pulse, the fuel isn't atomized as much, and you wind up with less power.... also, engines make more power when run slightly on the lean side... one more thing, low fuel pressure is usualy noticable at high RPM, at low RPM there is almost always enough pressure for the engine to make peak low end power.

When tuning fuel pressure, disconnect the battery for a few minutes first... then start the car and test for air/fuel ratio... by disconnecting the battery, you go back to the regular injector pulse length, which will give you optimum fuel spray
 
U

UB2 SLOW

Guest
Thanks, I will try that tonight. I also might try to readjust the throttlebody. I will let you know.
 
Joined
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Messages
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Tallahassee, FL
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none right now :(
I just read your post with all the mods you did to your car... with the bigger injectors, pressure is definitely less important... you are already flowing way more than you were before... the idle speed code could also be from the car not being able to deal with all the extra fuel... this would throw everything out of whack, and put the idle out of range of what the system can handle... the first step i would take is put the fuel pressure back to normal and reset the computer by disconnecting the battery... after that, start your tuning....

Just keep in mind, your list of mods all favor high RPM's... when you got the computer re-programmed, did they change the shift points and increase red-line? An educated guess tells me you are a MINIMUM 500 RPM higher for peak HP, and i really think it is more around 1000+ RPM's higher... your LT1 should be making much more horsepower, but you have to get way up in the RPM's to use it.

Another note, your stall converter could be messing with your idle as well... I have seen a couple different approaches to fixing a low idle problem on a modified engine... If you need to rig it for a short while, take a pencil eraser, cut it off the pencil, and stick it between where the metal bracket hits the throttle body (cut to proper thickness)... you can use rubber cement to keep it there, which will allow you to take it off easily... obviously this is only a temp. mod, but if it works, may help you trouble-shoot the problem. (also keep in mind, if the eraser falls off while you are driving, your car will drop in idle very low until it figures things out, and could stall when going back to idle)
 
F

FordNoMore!

Guest
I would just tell them that the Temprature is just not right to Cook rice that nite.:beer
 
U

UB2 SLOW

Guest
I had Ed Wright Reprogram the Computer. The new settings are 6600 rev limit, 6200 shift, 900 idle in park, 750 in gear. I was hoping that the 2800 stall convertor and the 3.73's would counteract the effects of the LT4 hotcam not having allot of Torque under 2300. I think I will try adjusting the throttle body again. I also will try to reset the computer too. The car is running strong as is, but I want to bring my best game when I slap these guys around.
 

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