Had a minor heart attack this weekend

[Lowe]

Fitted a nice new boost gauge since my old one was a bit on the big side, and it was silver/white faced. Since I went back to black dials, I wanted a smaller black boost gauge. Not a problem, spoke to Mark at Splitfire UK and picked one up the same evening. We fitted it and then took it out for a drive to make sure it was working...

OMFG!

Whereas before I was running 14psi, it's magically gone up to 16, spiking to 17!

So.. which one's telling the truth?


Luckily if it is running 16 psi it's not detting (good old Grp A carb and Optimax!) and I've been assured it's OK running at that sort of pressure.

[IainB]

Can you get hold of a gauge that has been calibrated... must be something kicking around where you work
At least something (not car based) that could give you a baseline to work from?

[Richie]

A good indication that a guage is working resaonably well is to check it in 2 areas -

1. Run the car at idle. The boost guage should be around 10-12psi in VACUUM i.e. neg boost

2. Switch car off and make sure the needle shows 0



Failing that you need to use a compressor setup which you know is accurate to begin with....

[Lowe]

My boost gauge is plumbed into the top of the carb so I don't get a negative reading on vacumn...

I guess I need to try someone elses gauge.

I'm thinking that the new gauge is correct, since I played around with my bleed valve a bit and it didn't seem to register on the old gauge.

[Richie]

Originally posted by Lowe
My boost gauge is plumbed into the top of the carb so I don't get a negative reading on vacumn...

Is this the same with the pipe going to the ECU to tell it what boost is running ??


Bleed valves are the devils work ..... Na, only kiddin..... Its only a problem when the owner is an arse with it

[Stringent]

Sounds good whatever it is

Don't post threads with topics like that! Scared me, nearly gave me a heart attack

[Lowe]

Originally posted by Richie
Is this the same with the pipe going to the ECU to tell it what boost is running ??


Bleed valves are the devils work ..... Na, only kiddin..... Its only a problem when the owner is an arse with it

That pipe will read vacumn, but it's not as accurate as the carb top.

I know the bleed valve is poo, but it's the only easy way of adjusting the boost. CBA with faffing with the acutator.

[Richie]

Tell me about it...... Spent ages adjusting the frikken actuator at one point

[Moby-Dick]

Originally posted by Lowe
That pipe will read vacumn, but it's not as accurate as the carb top.

I know the bleed valve is poo, but it's the only easy way of adjusting the boost. CBA with faffing with the acutator.

go get a dawes ( bren) device from apex its much less prone to spiking than the bleed valve and only costs about 30 quid. I've got an adjustable actuator on mine but it looks like a pig to change ( not putting my hand near a hot t28 ! )

[Richie]

Originally posted by Moby-Dick
( not putting my hand near a hot t28 ! )

Fondly remembers burning all the hair on his arms trying to adjust the actuator on a KKK-K16

[Lowe]

Problem is with a Dawes device, or similar ball and spring is that it puts a *lot* of strain on the actuator since they're not designed for on/off opperation.

Have a read of this.

http://www.rtoc.org/boards/thread.as...&TopicID=18849

[Moby-Dick]

most of the sxoc lot have one ( hence the name bren device as he is the main man at apex ;-) )
dont think I've seen ayone claim to have a failed actuator though !