Discussion
When I hit 6000 revs in 2nd I seem to be short of 60mph. Does this sound like normal gearing for a 400SE ? Didn’t expects to have to use 3rd to hit 60 and don’t really want to over rev it either.
Don’t get me wrong it’s not a problem and it pulls like a train in 3rd well into license endorsement territory.
Don’t get me wrong it’s not a problem and it pulls like a train in 3rd well into license endorsement territory.
I seem to remember reading a roadtest of a 350i in a TVR book (Gold Portfolio I think). The roadtester made some comment about having to rev the engine to about 6200rpm to acheive 60 in 2nd gear, and got a 0-60 time of 6.0 seconds. I know that this isn't a 400SE, but the gearing may be the same.
When I hit 6000 revs in 2nd I seem to be short of 60mph. Does this sound like normal gearing for a 400SE ? Didn’t expects to have to use 3rd to hit 60 and don’t really want to over rev it either.
Don’t get me wrong it’s not a problem and it pulls like a train in 3rd well into license endorsement territory.
I get about 40mph in first, a shade over 60 in second, 100 in 3rd, 120 - 125 4th, and 5th all the way.
Incidently, I can usually change down from 4 - 3rd at 85 mph when barrelling into corners and using the box to slow me down.
I have a rev limiter which kicks in about 5500 when not under load, and at 6500 when under load.
Incidently, I can usually change down from 4 - 3rd at 85 mph when barrelling into corners and using the box to slow me down.
NO!!! Engine braking is a No No.
1. The rear wheels can lock up because of the engine torque.
2. Clutches/transmission/Gearboxes cost a lot more than brake pads.
shpub said:
Incidently, I can usually change down from 4 - 3rd at 85 mph when barrelling into corners and using the box to slow me down.
NO!!! Engine braking is a No No.
1. The rear wheels can lock up because of the engine torque.
2. Clutches/transmission/Gearboxes cost a lot more than brake pads.
Ahem ..... The wheels will only "Lock up" if you donot balance the engine revvs with the speed, ie if there is a difference, and if you let the clutch up too quickly. (Notice that I also mentioned I double de-clutch). Once the clutch is engaged, the engine will brake the transmission and this is then suplimented with application of the brakes.(Ive been driving the car like it for almost 6 years.. if it was bad, it would have manifested itself before. Im still on my origional clutch, and transmission).
It also allows me to use full power 3/4 through the corner to enduce slight overstear and increase / maintain my speed through corners.
I will grant you that the V8 has a lot of mass ( intertia). but it comes down to the driver and his technique to avoid damage to the clutch / transmission when performing such things.
Incidently, when using the double de-clutch method, I can full power shift up, and also change down without using the clutch at all.
>> Edited by jvaughan on Wednesday 9th April 14:23
>> Edited by jvaughan on Wednesday 9th April 14:27
I reckon it's not just inertia, but available engine braking power.
I'll admit to braking on the engine a fair bit and only since I changed the cam from a knackered 234 to a shiny new 404 cam have I noticed any loosness from the back end. Shed loads more mid range power and engine braking than the old cam.
I'll admit to braking on the engine a fair bit and only since I changed the cam from a knackered 234 to a shiny new 404 cam have I noticed any loosness from the back end. Shed loads more mid range power and engine braking than the old cam.
It is a pretty bad habit to get into because it does knacker the transmission, and there will a time when you get it wrong or the surface is that bit greasy and the car will spin quicker than you know it. Cars with lesser power are less susceptable but as you increase the power, this becomes more critical and the chance of it ending up nasty is higher.
Engine braking also applies the braking on the rear wheels which have less grip because the weight has transferred to the front. This is another reasosn why a rear wheel lockup is easily done. As a braking technique it is not as efficient or as fast as using the brakes, irrespective of how many times you double declutch.
One of the reasons our insurance is so high is that TVR have allegedly the highest single vehicle accident rate and one of the biggest reasons is engine braking. Yes it used to be taught when power was small and brakes are awful but that is no longer the case. Brakes are for stopping. Gears are for going.
>> Edited by shpub on Wednesday 9th April 15:04
Engine braking also applies the braking on the rear wheels which have less grip because the weight has transferred to the front. This is another reasosn why a rear wheel lockup is easily done. As a braking technique it is not as efficient or as fast as using the brakes, irrespective of how many times you double declutch.
One of the reasons our insurance is so high is that TVR have allegedly the highest single vehicle accident rate and one of the biggest reasons is engine braking. Yes it used to be taught when power was small and brakes are awful but that is no longer the case. Brakes are for stopping. Gears are for going.
>> Edited by shpub on Wednesday 9th April 15:04
Steve, point taken.
But I did manage to cook my SEAC brakes on Devon A-roads prior to the rebuild; before accusing me of loony driving it was nothing I wouldn't have expected my everyday Alfa to have coped with.
I suspect it might have been pad selection by the previous owner but I never had the chance for comparison as I went for a brake upgrade as part of the rebuild.
But I did manage to cook my SEAC brakes on Devon A-roads prior to the rebuild; before accusing me of loony driving it was nothing I wouldn't have expected my everyday Alfa to have coped with.
I suspect it might have been pad selection by the previous owner but I never had the chance for comparison as I went for a brake upgrade as part of the rebuild.
350mk2 said:Steve I can't help but think the reason TVR's have more accidents than most is the fact they do not employ ABS or traction control and have a power to weight ratio of a SR71 Blackbird! - precisely the way it should be too!!
A contributory factor I agree but many of the the car suddenly spun incidents I have seen on track days have been caused by engine braking either intentionally or not (driver error - been there myself I have to say).
I was assessing drivers a couple of years ago on a track day and it was amazing the number of owners that did this. I was even told by one that it made the car safer because it was more gentle as the car lurched on the wet track. I have never been so glad to get out in my life!
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