Jump to content
SAU Community

Recommended Posts

is it just in certain rev range or does it happen in differnt gears?

reason I'm asking is, my car pulls hard like a school boy with a stack of porno in first second and third gear, all the way up to/close to redline. The fourth gear and fifth seems a little lacking in torque. I pu the foot down and the car sound like its suffocating when reving higher. I'm wondering if thats a flat spot or if it is just because of the standard dump/front and cat restricting the air flow when the boost is increased.

Edited by lingeringsoul
oh well, no big deal anyway, once I order the split dump/front pipe and put on the high flow cat, I'll give it another test and then get it tuned properly. Thanks for all the info guys

yeah i'd put it down your exhaust restriction!

you should have just asked me what a flat spot was! I was talking about mine all the way to newcastle the other week! lol

reason I'm asking is, my car pulls hard like a school boy with a stack of porno in first second and third gear, all the way up to/close to redline. The fourth gear and fifth seems a little lacking in torque. I pu the foot down and the car sound like its suffocating when reving higher. I'm wondering if thats a flat spot or if it is just because of the standard dump/front and cat restricting the air flow when the boost is increased.

That's not a "flat spot" per se.

A flat spot would be if your school boy in 2nd gear stopped for a little while between say 3000-3200rpm before going hard again. That would be a flat spot.

What you're doing is underloading the engine. To see even the middle top of 5th in my car you're doing around 250kmh+ so if you whip out 5th and it isn't down the hill and you're doing 80 you're not going to have the response when you're in boost in 3rd.

yeah i'd put it down your exhaust restriction!

That's really not it. See above. If it WAS exhaust restriction it would be RPM dependant and it would be a gradual curve/taper in restriction. This is because the restriction would be directly relative to the volumetric output of the engine at that RPM/load. So you wouldn't experience this as a flat spot, unless for some reason your exhaust was changing in diameter as you accelerated.

By your description in your first post it seems normal - if you're worried get on a mountain/racing bike and see what happens when you pedal at a low gear, then at the same speed click it into the highest gear. When you pedal at this point you'll notice you're expending more effort to move the bike - that's the same thing.

Either way a good exhaust will free your engine anyway :woot:

That's not a "flat spot" per se.

A flat spot would be if your school boy in 2nd gear stopped for a little while between say 3000-3200rpm before going hard again. That would be a flat spot.

What you're doing is underloading the engine. To see even the middle top of 5th in my car you're doing around 250kmh+ so if you whip out 5th and it isn't down the hill and you're doing 80 you're not going to have the response when you're in boost in 3rd.

That's really not it. See above. If it WAS exhaust restriction it would be RPM dependant and it would be a gradual curve/taper in restriction. This is because the restriction would be directly relative to the volumetric output of the engine at that RPM/load. So you wouldn't experience this as a flat spot, unless for some reason your exhaust was changing in diameter as you accelerated.

By your description in your first post it seems normal - if you're worried get on a mountain/racing bike and see what happens when you pedal at a low gear, then at the same speed click it into the highest gear. When you pedal at this point you'll notice you're expending more effort to move the bike - that's the same thing.

Either way a good exhaust will free your engine anyway :P

oops, i thought he did say it was rev range specific! Nevertheless you explained some things I didn't know before!

btw.. I know who i'll be pming when i need help with my car!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Did you pay with a credit card? I'd be putting a charge back through then finding a new sparky to sort it out. 
    • If you mean the alarm immobiliser; theyre internal to the alarm itself which makes that difficult; I couldnt even see where he put it; its not in the same place as last time; but with all black wiring it might be very challenging to trace  I had someone turn the key for me as I know it only primes for a couple of seconds As my post above; I am getting no voltage to the pump at all; but I am testing continuity of the power line (SB) from the pump plug to the relay fine. As well as the negative from the pump plug to a 12V constant.    Yeah; he blammed the no start on a bad battery; said I needed to get a new battery and it'll start. Turns out the battery drained because the tail lights had been on for half the day during the install (the rubber cushion on the brake switch gave out while he was testing it as I have a picture of the car from that morning with the tail lights off..i've replaced that). The battery was turning over the engine just fine for a long time; but got low since lights were draining it so it was too low to test a start after he finished. I bought a new one on his advice...$250 wasted. My original battery charged up just fine and is healthy.    It was running perfectly fine when I messed up the old alarm (programmed out the remotes). He couldnt start it after removing the old alarm; my assumption is that when he unhooked it; he didnt bridge the circuit back when trying to start it. Its always been perfectly fine. The ECU swap and pump were 2 years ago. It's never missed a beat in that time. 
    • This is a big issue for me without the diff. I just have zero drive from the passenger side when drivers side has no traction. Bec's parents place has a crazy steep driveway with odd camber and I have never been able to get up. My bro-in-law's 130i with an (unknown brand) LSD gets up fine as does their dad's Hiace. My car stays at the bottom. We have other odd camber roads around here as we're elevated a bit and if it's raining I can get totally stuck around some hairpins. 
    • Yeah, I am super excited for this.
    • Was the car running before he touched the car?
×
×
  • Create New...