My GTZ really lacks compression braking....

[DB4G63]

Hi All

Have owned a AE101 GTZ for about 8 months now, love the power and nimble feel to the car, and she looks gorgeous. Its also a bit rare thse days (well compared with WRX Altezza etc...)

My only gripe is living in hilly Dunedin when driving down a hill, changing gears to slow down does well.... bugger all. Even knocking her into second just makes her growl and well not really slow down much. Changing down in traffic is about as pointless, I feel myself overusing the brakes like (dare I say it ).... a dirty auto...

I have had some poosy cars in the past, all Mitsi Galants/Eterna and a Lancer but they all were magic for travelling down hills, simply throw into third and brake occasionally (10-15 seconds )

My mate reckoned it was those revy 4AGE's. I drove a red top 16v and it had wicked compression braking....

Anyone know why this is the case?

[fuel]

Lack of compression perhaps?

A GTZ has lower compression than a Galant or Lancer.

[beeker]

Speak to any professional driver, use the brakes to slow, not the engine.

[Lloyd]

I wouldn't want to just use brakes on the road. Cook them easy around Dunedin

[matt dunn]

Engine braking is dependant on the compression of your engine.

Supercharged engine's are low compression so therefore low amount of engine braking.

Matt

[RomanV]

Speak to any professional driver, use the brakes to slow, not the engine.

That's retarded, on the track with a massively overbraked car perhaps, not in an ordinary car going down a particularly taxing hill.

BTW if you're clever you can use your engine as a dynamic brake bias adjuster.

[beeker]

Speak to any professional driver, use the brakes to slow, not the engine.

That's retarded, on the track with a massively overbraked car perhaps, not in an ordinary car going down a particularly taxing hill.

BTW if you're clever you can use your engine as a dynamic brake bias adjuster.

I suggest you research your topics prior to making such statements. I've been on so many courses over the years and every professional instructors states such. Using gears for holding speed is ok, but you use the brakes for braking. Too many people try and use the driveline for slowing the car, and its simply not designed for that.

[Loudtoy]

Speak to any professional driver, use the brakes to slow, not the engine.

That's retarded, on the track with a massively overbraked car perhaps, not in an ordinary car going down a particularly taxing hill.

BTW if you're clever you can use your engine as a dynamic brake bias adjuster.

I suggest you research your topics prior to making such statements. I've been on so many courses over the years and every professional instructors states such. Using gears for holding speed is ok, but you use the brakes for braking. Too many people try and use the driveline for slowing the car, and its simply not designed for that.

Now that makes more sense than your first bit, on 1st reading it i assumed that you were meaning not even for holding speed down hill etc.
Hey how about reatarders on trucks etc can you use them to aid with braking??

[pidge]

I've got a AE101 GTZ - and what I'd notice is that I'd need to "pump" the brake (press down firmly, release, then press down again) to really get the brakes to bite.

Once the brakes fluid had had a proper flush and the brake pads replaced (finally, after 80,000km!), that problem went away...

[RomanV]

I suggest you research your topics prior to making such statements. I've been on so many courses over the years and every professional instructors states such.

I've been surfing at beaches like Piha and Bethels for several years, and you can tell who does, and doesnt engine brake; by who's brakes are on fire by the time they get to the bottom of the hill.
Do you suggest that they dont drive down hills, as it obviously "isnt designed for that"?
Unless you think that brakes catching on fire is part of the design criteria?

Using gears for holding speed is ok, but you use the brakes for braking. Too many people try and use the driveline for slowing the car, and its simply not designed for that.

How do you know that engine braking isnt designed as part of the criteria for a car?
If I had a car that blew up because of engine braking, I'd set it on fire, and the company it was made by too.
Your implication is that you're somehow going to damage the drivetrain etc, because it 'isnt designed for that'. What a load of horse shit.
You're making it sound as if engine braking is the equivilent of running up to Atlas, and giving him a good kick in the nuts while he's trying to support the weight of the world on his shoulders.
The drivetrain links rotational forces, between the tires and the engine.
If it's incapable of transmitting force in the opposite direction, then cars would blow up when put into reverse, long before blowing up from engine braking! I've seen enough reverse donuts in my time, to know that the transmissions of cars are far more than strong enough to take forces in the opposite direction.

If you're trying to say that engine braking is bad for the engine, then I'm also calling BS on that. Prove that it does, not just "It's not designed for that".
P.S. Some modern auto/tiptronic cars engine brake automatically.

Engine braking on a race track, or on a race car is a completely seperate issue to driving on the street. Race track driving techniques =! road driving techniques.

[Jazza]

Try driving to Matarangi (1 hour from coromandel) in an ef civic without engine braking. You wont make it.

[Brick]

i found engine braking in the wet at ruapuna helped me stop alot faster and i wouldnt lock up when gearing down. I always gear down and ive never had any probs wat so ever

[Adamal]

I think the correct thing to say would be not to rely completely on your engine for braking. Use it as an assist to braking. Should your foot slip or you have a brake faliure, it could make a hell of a difference compared to coasting along in a higher gear.

And Roman has a very good point. An engine produces a force which more often than not, will accelerate it at a rate greater than it can stop it. If it were to damage the drive lines engine braking, then accelerating with it would destroy it, especially in forced induction engines, where boost is either absent or greatly lacking under decelleration.

[Chickenman]

It should all be a fluid symbiosis of engine and brakes.


Be no need for heel/toe if you just used your brakes to retard speed on the track.

[RomanV]

Be no need for heel/toe if you just used your brakes to retard speed on the track.

No way!

Downchanging when the car is balanced right on its adhesion limit REQUIRES rev matching, or you're looking at locking up your drive wheels.

I did this a few times at the small taupo track, didnt rev high enough when rev matching changing down into third, rear momentarily locked, spinout!

[Chickenman]

How do you mean no way?

I said: If you braked without using your engine at all there wouldn't be advanced techniques like heel/toe revmatching etc.


Reading and comprehension not a big thing when you were at primary?

[RomanV]

Be no need for heel/toe if you just used your brakes to retard speed on the track.

No, what you said there was basically " If you dont engine brake, you dont need to heel toe" Which isnt right, is it?

You could not engine brake at all, and you'd still need to heel toe, as the disparity between correct engine RPM and wheel speed would jolt the vehicle.

Even if you never engine brake at all, this is still necessary.

[EVLGTZ]

Try driving to Matarangi (1 hour from coromandel) in an ef civic without engine braking. You wont make it.

1 hour? u drive like a nana!! oh hold on you said civic...may bad!!!

Good road thru there. Awesome for towing the boat thru there and also further north of coro.

Anyway back on topic - use to notice that in my GTZ compared to the n/a car I also drove. Pretty common feeling to most turbo or s/c cars due to the lower compression

[mr pad]

Not only the lower comp, but how high is it idling?

If its idling higher that say.. 1000rpm, its going have a big affect if your going down hill in gear...

And of corse you need to use engine braking when racing.

[Chickenman]

Be no need for heel/toe if you just used your brakes to retard speed on the track.

No, what you said there was basically " If you dont engine brake, you dont need to heel toe" Which isnt right, is it?

You could not engine brake at all, and you'd still need to heel toe, as the disparity between correct engine RPM and wheel speed would jolt the vehicle.

Even if you never engine brake at all, this is still necessary.

Are you stupid?

It was a totally theoretical situation.. if you aren't supposed to use your engine to brake (as someone else stated in this thread) then you wouldn't be changing down anyway and cruising around in 5th. As soon as you change down whilst slowing you are initiating engine braking. So to drive without using engine braking you would have to put it in neutral/hold the clutch in and brake into the corner... where you would spinout as you tried to put it in gear to continue.

FFS, can't anyone use their brain these days.

edit/ obviously not me.. I spelled their incorrectly...