N/A Engine kick in?

[lammi]

Hiya guys,

I am still getting the hang of my liberty but I was wondering when the N/A kicks in? does it kick in like the v-tec does?

I don't have a GT, it's just the 2.5i, thanks guys!

LaMMi

[teK--]

There is no variable valve timing (vtec). Max torque is at around 4400rpm which is the optimal upshift point.

[nytrojen]

I miss my Silvia and its 7500rpm redline

[smythie]

There is no variable valve timing (vtec). Max torque is at around 4400rpm which is the optimal upshift point.

That is the optimal speed for a CVT to operate when driving along with no more than medium acceleration.

What are you referring to when you say "optimal"?

Straight out acceleration or track driving? Optimal shift point is as close to max engine speed as possible as long as power doesn't tail off significantly
Mild acceleration? Where ever you wish really, there isn't an optimal speed - it's up to the seat of your pants
Enthusiastic back road driving? In the case of that engine I'd be suggesting up around 5000-5500 (to allow the next gear to start off close to peak torque) to give you maximum shove
Waffling around suburbs trying to save fuel? Somewhere around 2500rpm.

Shifting at the torque peak is going to drop you well back down the torque curve for the next gear. This is far from optimal if you are wanting to use the torque of the engine to accelerate

[sh1ft]

hey,

the good old 2.5i's dont move at all till they get close to around 3000. i find i'm always working the gears to keep it between 3000-6500 through the hills
mainly sticking to 3rd if fast flowing, shifting back to 2nd or even 1st for hair pins as it will have some pull (i did only say some! )
if kept close or above the 3k mark

[lammi]

ahahah thanks guys,

I drive a bit more agressive now. (as much as my 2.5i can handle)

it's just that at above 4-5k+ RPM, the engine sounds like it's about to blow haha, so i never really pushed it. I was driving like an old folk shifting at 2.5k rpm last week and got 9.8L/100KM and this week I have been playing with it, I can't get under 11K/100KM lol

LaMMi

[teK--]

There is no variable valve timing (vtec). Max torque is at around 4400rpm which is the optimal upshift point.

That is the optimal speed for a CVT to operate when driving along with no more than medium acceleration.

What are you referring to when you say "optimal"?

Straight out acceleration or track driving? Optimal shift point is as close to max engine speed as possible as long as power doesn't tail off significantly
Mild acceleration? Where ever you wish really, there isn't an optimal speed - it's up to the seat of your pants
Enthusiastic back road driving? In the case of that engine I'd be suggesting up around 5000-5500 (to allow the next gear to start off close to peak torque) to give you maximum shove
Waffling around suburbs trying to save fuel? Somewhere around 2500rpm.

Shifting at the torque peak is going to drop you well back down the torque curve for the next gear. This is far from optimal if you are wanting to use the torque of the engine to accelerate

I haven't seen the torque curve of the EJ25 however I always thought that generally on a SOHC engine, that once you hit the torque peak the torque starts to taper off? (How rapidly this happens in an EJ235 I am not sure). This is the reasoning behind my suggestion to shift at torque peak, so that when you are in the next gear you are accelerating up towards maximum torque again.

Correct me if I'm wrong, engines are not my forte

[teK--]

ahahah thanks guys,

I drive a bit more agressive now. (as much as my 2.5i can handle)

it's just that at above 4-5k+ RPM, the engine sounds like it's about to blow haha, so i never really pushed it. I was driving like an old folk shifting at 2.5k rpm last week and got 9.8L/100KM and this week I have been playing with it, I can't get under 11K/100KM lol

LaMMi

Yeah I'd have to agree that the engine can sound rather raspy at above 4000rpm especially if the exhaust is stock. It's probably choking a bit and fitment of just straight through mufflers I found freed up the top end a lot.

I am blown away by how low the fuel consumption can get in these cars. On the weekend I drove >250kms up to Shepparton so it was highway all the way, and even without using cruise control and wandering from between 100kph to 110 and above occasionally to overtake, I still managed to get 7.6L/100KKms on the trip.

[smythie]

There is no variable valve timing (vtec). Max torque is at around 4400rpm which is the optimal upshift point.

That is the optimal speed for a CVT to operate when driving along with no more than medium acceleration.

What are you referring to when you say "optimal"?

Straight out acceleration or track driving? Optimal shift point is as close to max engine speed as possible as long as power doesn't tail off significantly
Mild acceleration? Where ever you wish really, there isn't an optimal speed - it's up to the seat of your pants
Enthusiastic back road driving? In the case of that engine I'd be suggesting up around 5000-5500 (to allow the next gear to start off close to peak torque) to give you maximum shove
Waffling around suburbs trying to save fuel? Somewhere around 2500rpm.

Shifting at the torque peak is going to drop you well back down the torque curve for the next gear. This is far from optimal if you are wanting to use the torque of the engine to accelerate

I haven't seen the torque curve of the EJ25 however I always thought that generally on a SOHC engine, that once you hit the torque peak the torque starts to taper off? (How rapidly this happens in an EJ235 I am not sure). This is the reasoning behind my suggestion to shift at torque peak, so that when you are in the next gear you are accelerating up towards maximum torque again.

Correct me if I'm wrong, engines are not my forte

That engine has the following on paper figures:
- max torque of 226Nm at 4400rpm
- max power of 121kw at 5600rpm

At 5600rpm the engine is still producing 206Nm of torque. It's not tailing off all that much. From experience flo, umm driving Outback hire cars you can easily run past 6000rpm without power tailing off much.

[teK--]

Thanks Smythie I'll keep that in mind for next time I'm on the track .

Most of the courses I would almost top out 2nd gear before the next corner and having to back off again, but generally I found that above 5000rpm there was not much more power before hitting 6,000rpm redline, so I was treating that 1,000rpm really as headway to avoid having to change up a gear.

[smythie]

For track work it can often be beneficial to run a gear higher in corners than you might for the same speed on a straight - particularly if you are learning the track. Run it out to redline (or when you feel power tapering off) when you don't have to worry about cornering - the longer you are able to spend accelerating in a lower gear, the longer you will be able to take advantage of that lower gear ratio.

The higher gear can reduce the amount of gear changes on the following straight but more importantly help settle the car/bike and have the engine feeling a bit less manic which can help reduce the amount of things your mind has to think about when feeling for the edge of the cornering envelope of your car/bike.

[Digital]

i've got a little 'friendly' with my pedal a few times taking it up to 6,000rpm and yes it did not sound great for the car at all..... is my car gonna crap itself soon or any other ways to 'enjoy' without stuffing her up? mine is auto btw lol

[tangcla]

[sh1ft]

[/quote]That engine has the following on paper figures:
- max torque of 226Nm at 4400rpm
- max power of 121kw at 5600rpm

I cant get over the power out put, my jet ski makes abit over 70kw more than it! still the good old 2.5i is great for what it worth.

I've removed and sealed off the factory air resi (sits under the airbox aka white jug lookalike) on mine makes it sound abit better high in the revs

[teK--]

For track work it can often be beneficial to run a gear higher in corners than you might for the same speed on a straight - particularly if you are learning the track. Run it out to redline (or when you feel power tapering off) when you don't have to worry about cornering - the longer you are able to spend accelerating in a lower gear, the longer you will be able to take advantage of that lower gear ratio.

The higher gear can reduce the amount of gear changes on the following straight but more importantly help settle the car/bike and have the engine feeling a bit less manic which can help reduce the amount of things your mind has to think about when feeling for the edge of the cornering envelope of your car/bike.

Agreed, on one particular course I experimented between staying in 2nd gear but with the engine revving its head off at over 5000rpm, or shifting up to 3rd and revving around 4000. Particularly I found that staying in 3rd felt quicker due to not being distracted by being close to redline and the engine screaming at me, but most significantly I carried a lot more speed through the turn due to less engine braking.

Thanks for the tip