LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Real weird issue...

Thread Tools
 
Search this Thread
 
Old 05-12-2006, 02:02 PM
  #1  
TECH Resident
Thread Starter
 
Charging TA's Avatar
 
Join Date: Jun 2005
Location: Finland
Posts: 875
Likes: 0
Received 0 Likes on 0 Posts
Default Real weird issue...

Hey guys,

First of all let me state that as far as I know my LT1 in stock, however its kind of a puzzle because... My LT1 sounds and rumbles alot nicer/louder than two other mint condition same-year LT1 TAs. My exhaust is stock, I have a (new) cat... Sometimes I think I have a cam because my idle almost seems to have a lopiness to it. Ive never driven another LT1 before so I can say if it feels faster.

So heres the issue: My dad yesterday wanted to drive and I had nothing against it, we turned onto a road from a parking lot and he was in first. He did not get on it but he gave it a bit of throttle just enough to get out of skip-shift (been on my list of things to do, was planning on deleting it when I replace my clutch but Ill probally do it this weekend), all of a sudden I thought he got on it but he said something just made more power.

I thought nothing of it and today when I left a parts store, I made a U-turn out of the parking lot and was in first... I was slowly accelerating and then just gave it a bit more throttle to get it out of skip-shift and held the throttle steady right about to shift into second and the car launches.

I cant explain it other than it feels as if the computer just went "more power!".

Anyone have any explanations on what could be happening? Its like all of a sudden a burst of power comes yet the throttle is being held steady, RPMs dont climb, the car just launches forward as if you hit a small shot of N20.

Thanks in advance.
Old 05-12-2006, 02:05 PM
  #2  
TECH Addict
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

¿Qué?
Old 05-12-2006, 02:11 PM
  #3  
TECH Fanatic
iTrader: (6)
 
lt197formula's Avatar
 
Join Date: Feb 2005
Location: Buda, Texas
Posts: 1,070
Likes: 0
Received 1 Like on 1 Post

Default

You might have a small cam in there check with the previous owner about that. The only logical explaination I can think of is maybe its just right where you peak power and the rest is in your head.
Old 05-12-2006, 02:17 PM
  #4  
TECH Resident
Thread Starter
 
Charging TA's Avatar
 
Join Date: Jun 2005
Location: Finland
Posts: 875
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by lt1 97 formula
You might have a small cam in there check with the previous owner about that. The only logical explaination I can think of is maybe its just right where you peak power and the rest is in your head.
Thats exaclty what I was thinking, but the RPMs did not rise by much at all, so it was real weird to be hitting it there.

The previous owner only owned the car for a little while and as far as I know doesnt know too much about cars, the guy before him was the original owner and Id have to do some long distance calling (and it would be kinda akward) to find out...

Ive had the car for over a year but just never noticed this before. And it happened to both me and my dad so... I dont think its in my head. In all honestly now that you mention the cam, I think back to karting... it feels just like when you hit the powerband on them and you just fly. But Ive never experienced the same in a car, and this happened at low speeds.
Old 05-12-2006, 02:30 PM
  #5  
TECH Fanatic
iTrader: (6)
 
lt197formula's Avatar
 
Join Date: Feb 2005
Location: Buda, Texas
Posts: 1,070
Likes: 0
Received 1 Like on 1 Post

Default

might just be right where the cam's power kicks in.
Old 05-12-2006, 02:31 PM
  #6  
TECH Addict
iTrader: (8)
 
Honda Hunter's Avatar
 
Join Date: Sep 2005
Location: The beautiful Kingdom of Bahrain
Posts: 2,401
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by lt1 97 formula
might just be right where the cam's power kicks in.
Vtec?
Old 05-12-2006, 02:33 PM
  #7  
TECH Resident
Thread Starter
 
Charging TA's Avatar
 
Join Date: Jun 2005
Location: Finland
Posts: 875
Likes: 0
Received 0 Likes on 0 Posts
Default

I should add... I passed emissions pretty well, I dont have the numbers with me (their at the other house). But I think that may be because emissions here get higher limits depending on how old the car is (not sure if they do that in the states because in Florida they stopped testing a like half a decade ago). However, when I bought the car I noticed the cat welded in was not a stock cat and it just last week broke apart... I remember running rich can break a cat. Could a small cam be causing it to be running rich (if it in fact is)?

Id like to get the TA on a dyno sometime.
Old 05-12-2006, 02:37 PM
  #8  
TECH Fanatic
iTrader: (6)
 
lt197formula's Avatar
 
Join Date: Feb 2005
Location: Buda, Texas
Posts: 1,070
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by Honda Hunter
Vtec?
No not vtec I meant the begining of the cams power range.

Like on my car since I have a fairly large cam it is very noticable when the cam's powerband begins.
Old 05-12-2006, 02:47 PM
  #9  
TECH Resident
Thread Starter
 
Charging TA's Avatar
 
Join Date: Jun 2005
Location: Finland
Posts: 875
Likes: 0
Received 0 Likes on 0 Posts
Default

Alright thanks lt1 97 formula, makes sense. You think theres any point in me getting a cable and logging the car someday? (Ive been meaning to get a cable anyways since as far as I know theres no one who tunes our cars here...)
Old 05-12-2006, 03:02 PM
  #10  
TECH Fanatic
iTrader: (6)
 
lt197formula's Avatar
 
Join Date: Feb 2005
Location: Buda, Texas
Posts: 1,070
Likes: 0
Received 1 Like on 1 Post

Default

Yea that would make sense to me if there is no one that tunes cars near you.
Old 05-12-2006, 06:58 PM
  #11  
TECH Apprentice
iTrader: (9)
 
Kanes2413's Avatar
 
Join Date: Jun 2005
Location: Arlington Hts,IL
Posts: 336
Likes: 0
Received 0 Likes on 0 Posts

Default

I have the same feeling in mine its a stock 93 lt1 but by the sound of the exhaust i thought it could be a cam but now i keep hearing more people not knowing if there car has a cam so i just imagine its how it sounds but i swear my car has more power than other lt1's and sometimes ls1's ive driven no joke its a good feeling
Old 05-12-2006, 10:25 PM
  #12  
TECH Fanatic
iTrader: (8)
 
sdm1234's Avatar
 
Join Date: Oct 2005
Location: Holland Twp/Milford, New Jersey
Posts: 1,420
Likes: 0
Received 0 Likes on 0 Posts

Default

What I would do first is eliminate ther skip shift. That way, you don't have to worry about it kicking in or not. Once that's out and gone, THEN do what you did before, and see if it still wants to push. Is it noticable in 2nd, as well?
Old 05-13-2006, 08:24 AM
  #13  
TECH Resident
Thread Starter
 
Charging TA's Avatar
 
Join Date: Jun 2005
Location: Finland
Posts: 875
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by sdm1234
What I would do first is eliminate ther skip shift. That way, you don't have to worry about it kicking in or not. Once that's out and gone, THEN do what you did before, and see if it still wants to push. Is it noticable in 2nd, as well?
I just came online to double check the skip-shift elimination steps and am doing that right now. Ive only experienced it happening twice so far, both times in first, havent tried any other gears nor have I tried to reproduce it (its always happened when I am leaving a parking lot and getting onto a road). I will probally go out and try to reproduce it later on today.

The only way I can provide a better idea is... imagine your in first rolling (completely off the clutch), holding the throttle steady (however the car is still speeding up, but not at all rapidly - real low speed limit roads) and all of a sudden its as if you were to get on it (not WOT, but just a good "punch") but yet you havent moved the throttle, nor do the RPMs shoot up (as if the clutch was slipping). It just seems like more power is being unlocked at that point.

Thanks again guys, Ill let you know if I can reproduce it.




All times are GMT -5. The time now is 10:45 PM.