Turbo's ?

spike's · 24 Jul 2006 at 20:25

Oracle said:
Pfft!! Turbos kicking in at 1800rpm for the win!

* if only it wasnt all over by 3800rpm!

lol. yep. i am now converted

Clarkey · 24 Jul 2006 at 20:35

Will Gill said:
disconnecting the actuator will disable the turbo, probably a complicated way to automate that with some funky stuff, but it would drive like a big lump of poo.

I wouldn't do that! Disconnecting the actuator will make the turbo boost out of control till it or something else blows up.

eidolon · 24 Jul 2006 at 20:44

Clarkey said:
I wouldn't do that! Disconnecting the actuator will make the turbo boost out of control till it or something else blows up.

Disconnecting it will stop it from boosting. Jamming it open will make it boost of control.

Jonjam · 24 Jul 2006 at 20:54

One way of switching "off" the turbo is to have a normal actuator on it that are ussually rated at around 50% of full boost . when the boost control valve is triggered it is very fast to react , so cuts the boost quickly , it then starts to float , almost like a tap been adjusted , if you take the normal boost control valve out of system and set up a variable boost valve you can adjust the boost from very low pressure to about 3 times actuator spring pressure , starts to get hard to control above that as the turbo's internal pressure in the exhaust side starts to lift the wastegate of its seat , I know this from playing with RS500 cosworths in my youth , managed to pile 35lbs of boost into one with 6.2 c.r. pistons in it and it worked for sprints and hillclimbs

Will Gill · 24 Jul 2006 at 21:19

eidolon said:
Disconnecting it will stop it from boosting. Jamming it open will make it boost of control.

quite bro

its a common mod used when breaking in new engines on scoobs, my mate had a 2.5 and had to do 2k off boost. It nearly killed him but its so good for the engine to be run in like that

Dandle · 24 Jul 2006 at 21:58

The_Dark_Side said:
i drove a caddy a while back and i'm sure when cruising along the engine switches off 3 or 4 of the cylinders.

for the more technically minded (simon, johnnycoupe etc) i have a question.
in cases like this, is it always the same cylinders that are switched off or is the order rotated around all of them?
the reason i ask is, if it's always the same pots that are deactivated then doesn't it put a lot of unbalanced and undue stress on the crank?

Most modern V8 mercs do this as do the V12s. They cut back the cylinders fired when in traffic or idling to save fuel. As you give them more throttle they fire the rest up depending on demand.,

Clarkey · 24 Jul 2006 at 22:37

Will Gill said:
quite bro

its a common mod used when breaking in new engines on scoobs, my mate had a 2.5 and had to do 2k off boost. It nearly killed him but its so good for the engine to be run in like that

Sorry, i must be losing my mind a little, I thought you meant disconnecting the boost hose from the intake not the actual rod.

eidolon · 24 Jul 2006 at 22:43

Clarkey said:
Sorry, i must be losing my mind a little, I thought you meant disconnecting the boost hose from the intake not the actual rod.

I've done that on my mates R5 GTT then I took it for a test drive.

I came off a roundabout and floored it, didn't so much accelerate really, just dug a R5 shaped hole in the road

The_Dark_Side · 24 Jul 2006 at 23:23

eidolon said:
I've done that on my mates R5 GTT then I took it for a test drive.

I came off a roundabout and floored it, didn't so much accelerate really, just dug a R5 shaped hole in the road

LMAO.
even now the R5 can be a force to be reckoned with on the road.
pushrods and carb and still it's a little stormer.

Perywinkle · 24 Jul 2006 at 23:26

There are plent of turbo kits around that limit boost to throttle position.
Been looking at some for the R1 engine in my indy that increase boost exponentialy with throttle possition.
eg 25% throttle will give you 10% of maximum achievable pressure, up to a pre desribed max.
Means much more controlable power output on lighter weight cars.

eidolon · 24 Jul 2006 at 23:32

The_Dark_Side said:
LMAO.
even now the R5 can be a force to be reckoned with on the road.
pushrods and carb and still it's a little stormer.

They're deceptively fast little things. I ran 14.5 sec down the strip a few times in mine with mods that cost me about 50p.

I rarely see them these days as I guess most of them have been written off but I've still got a soft spot for them.

Clarkey · 24 Jul 2006 at 23:36

Perywinkle said:
There are plent of turbo kits around that limit boost to throttle position.
Been looking at some for the R1 engine in my indy that increase boost exponentialy with throttle possition.
eg 25% throttle will give you 10% of maximum achievable pressure, up to a pre desribed max.
Means much more controlable power output on lighter weight cars.

Whats the point in that, you're not going to be making much boost at part throttle anyway :confused:

Perywinkle · 24 Jul 2006 at 23:50

Depends on the size of the turbo with bike engined cars. With the smaller capacity, you don't need such a large turbo, hence much lower spin up times.
It just means the car is much more drivable when pootling around.
Driven seven reps with and without this sytem, and I must say it's far easier to control such a light car with the progressive boost system.

Clarkey · 24 Jul 2006 at 23:52

Sounds like it would be better off with an NA tbh

The_Dark_Side · 25 Jul 2006 at 00:29

eidolon said:
They're deceptively fast little things. I ran 14.5 sec down the strip a few times in mine with mods that cost me about 50p.

I rarely see them these days as I guess most of them have been written off but I've still got a soft spot for them.

rot boxes to be honest, although i have to agree with you loads of them will have been bent large style.

for me the suspension was the most amazing feature of the car.
to be so good from the factory was a total surprise.

Will Gill · 25 Jul 2006 at 07:17

I still love r5gtt's, must scan pictures of my past cars, they were all owned way before the days of digital photography

I keep meaning to buy one for £500 and just keep it in the garage and stroke it, I used to just be happy to sit in one and look at the instruments, best instrument panel ever

The_Dark_Side · 25 Jul 2006 at 18:14

Will Gill said:
I still love r5gtt's, must scan pictures of my past cars, they were all owned way before the days of digital photography

I keep meaning to buy one for £500 and just keep it in the garage and stroke it, I used to just be happy to sit in one and look at the instruments, best instrument panel ever

when we first locked horns in here it got pretty heated.
now i want to adopt you and buy you trifle.

you loon.

eidolon · 25 Jul 2006 at 18:18

Will Gill said:
I still love r5gtt's, must scan pictures of my past cars, they were all owned way before the days of digital photography

I keep meaning to buy one for £500 and just keep it in the garage and stroke it, I used to just be happy to sit in one and look at the instruments, best instrument panel ever

I've got a pic which is a bit like that. I think there is something wrong with the speedo though.

Will Gill · 25 Jul 2006 at 18:19

Acolyte · 25 Jul 2006 at 18:48

R5 GTT's rock, i will have one as a "weekend fun car" one day