engine response "barrier"
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,613
Likes: 0
From: Orlando FL
engine response "barrier"
i'm looking for solutions to an odd problem. when i romp on the gas, it seems like up until 2400RPM or so, the engine isn't "giving it its all"...it really takes its time getting going...then once i cross that barrier, its like a whole new car...it slams me into my seat, RPM skyrockets...and it "feels" like a vette. a friend of mine says it needs headers, because the exhaust is too restrictive. its not a fuel starvation issue, cuz it does it all the time...injectors, plugs, wires, fuel filter have all just been changed with lots of other things too. i know all the power curves are up in that 2400 range...but does it really change THAT noticably? does any else have that problem? what was the solution? TIA
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,613
Likes: 0
From: Orlando FL
Re: engine response "barrier" (bogus)
mods are minimal...gutted cats...flowmaster exhaust...removed all the air pump stuff that feeds the cat...hypertech stage one chip, 180* t-stat. thats really it...
i'm not saying that its not a monster off the line...it is...but its a wicked scary monster with 3 heads that breathe fire once i cross over 2400RPM
i'm not saying that its not a monster off the line...it is...but its a wicked scary monster with 3 heads that breathe fire once i cross over 2400RPM
Burning Brakes
Joined: Feb 2003
Posts: 1,212
Likes: 0
From: OH
Re: engine response "barrier" (Orlando85UCFvette)
I dunno but sounds about right for an 85. We do have a higher stall then later years 2000rpm. Mine would open up around 2500 as well. But still plenty of low-end before that, would easily break traction way below that limit. Headers certianly don't hurt anything. I felt a nice improvement in low-end pull, but more in the mid-ranges for sure. Aftered adding the TPIS headers I could break traction at 60-70 on the freeway if I really gave it hell.
With gutted cats and Flowmasters your exhaust isn't restricted by any means. The stock manifolds are not that bad really, just like a shorty header. Not great for upper end power, but then niether is the intake setup.
[Modified by rsafier, 1:40 PM 5/7/2004]
With gutted cats and Flowmasters your exhaust isn't restricted by any means. The stock manifolds are not that bad really, just like a shorty header. Not great for upper end power, but then niether is the intake setup.
[Modified by rsafier, 1:40 PM 5/7/2004]
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Re: engine response "barrier" (Orlando85UCFvette)
My 90 is the same...expecially in 2nd or 3rd..
Yes I can break tyres, but the car seems too lazy :sleep: up to 2500-2600 rpm. After that barrier it runs much quiker (the progression on RPM is not so good as I was expected from a Corvette... but definitively is good)
I have a 2.73 rear. ... figuring with a 2.59....
-Beppe-
Yes I can break tyres, but the car seems too lazy :sleep: up to 2500-2600 rpm. After that barrier it runs much quiker (the progression on RPM is not so good as I was expected from a Corvette... but definitively is good)
I have a 2.73 rear. ... figuring with a 2.59....
-Beppe-
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: engine response "barrier" (Orlando85UCFvette)
Try some more mods:
-cut lid with K&N filter
-use the metod on my site to tweak the TPS settings
-bump base timing till just below ping or knock retard
-a 160deg stat would help
-a 2 1/2" mandrel-bend front Y would be better than the stock with gutted pre-cats
-install cut back spark plugs gapped to stock setting
-under drive crank & over drive alt pulleys.
I think you will notice the biggest improvement in throttle response from the timing tweak and underdrive pulley.
What is the stall RPM on your stock TC, 1,500rpm or 2,000rpm? Roll out at about 10-20mph and pop the accelerator and note to what RPM the tach jumps before the MPH realy starts to climb. If your stall is 1,500rpm a 2,000rpm TC will realy help street driving by betting you up in the power band at the hit of the throttle.
-cut lid with K&N filter
-use the metod on my site to tweak the TPS settings
-bump base timing till just below ping or knock retard
-a 160deg stat would help
-a 2 1/2" mandrel-bend front Y would be better than the stock with gutted pre-cats
-install cut back spark plugs gapped to stock setting
-under drive crank & over drive alt pulleys.
I think you will notice the biggest improvement in throttle response from the timing tweak and underdrive pulley.
What is the stall RPM on your stock TC, 1,500rpm or 2,000rpm? Roll out at about 10-20mph and pop the accelerator and note to what RPM the tach jumps before the MPH realy starts to climb. If your stall is 1,500rpm a 2,000rpm TC will realy help street driving by betting you up in the power band at the hit of the throttle.
