Not sure about boost

Just wondering if my car is boosting properly. Ever since i fitted my guage it's always said 0.6 bar instead of 0.8 but i've always put this down to an inaccurate guage (its a cheapo) or a kinked tube behind the dash or something. But i've started to wonder....

Here is a video of my boost guage (hard to see, sorry) when i'm sitting still and give it a quick rev. I think this is reading correct, so if this is reading correct when doing this does that mean it will definately be reading correctly when on boost?

Is there any other way apart from doing the TTC mod that i can check my boost?

Cheers

Those gauges are rubbish mate!!!

I had one on an old car and it was innacurate!

What does it sit at when the engine's off? It should sit at 0. My old one didn't.

Yeah it goes to 0, does that mean it *should* be accurate when boosting?

God knows, it's cheap tat.

No offence, like I said, I bought one recently for my last car.

Lol, no offence taken i know it's cheap tat

Why would it going to 0 mean its reading accurate? I can get positive or negative boost on a gauge when revving depending how hard i push it.

Tricky one this!

I have run several autogauges on a few turbo cars in the past, as I refuse to use electronic boost gauges and couldnt find many mechanical ones I liked.

Both previous gauges were accurate on boost.

However Im not 100% about vacuum accuracy, as if you take a look at the gauge when the engine is off but ignition on (eg/ the gauge has power) then does the needle sit bang on Zero?

I would say the gauge is right and your car is wrong but Im sure some will disagree.

The easiest way to know for sure is to fit a better mechanical gauge (let me know if you find a nice looking black face one!) and see what it reads.

The easiest way to know for sure is to fit a better mechanical gauge (let me know if you find a nice looking black face one!) and see what it reads.

HKS thats the one i have.

you wont get positive boost unless the car is under load anyway, it should read negative boost (vacuum) when idling too. As for the accuracy, do you have another gauge you can borrow ? How does it feel in the seat of your pants gauge ?

you wont get positive boost unless the car is under load anyway, it should read negative boost (vacuum) when idling too. As for the accuracy, do you have another gauge you can borrow ? How does it feel in the seat of your pants gauge ?

I can get 0.3 Bar positive boost showing on my gauge by revving in P (auto). I showed this to some people at one of the SEM meets a while back

Why would it going to 0 mean its reading accurate? I can get positive or negative boost on a gauge when revving depending how hard i push it.

I dunno? Thats why i'm asking you guys

Tricky one this!

 

I have run several autogauges on a few turbo cars in the past, as I refuse to use electronic boost gauges and couldnt find many mechanical ones I liked.

 

Both previous gauges were accurate on boost.

However Im not 100% about vacuum accuracy, as if you take a look at the gauge when the engine is off but ignition on (eg/ the gauge has power) then does the needle sit bang on Zero?

 

I would say the gauge is right and your car is wrong but Im sure some will disagree.

 

The easiest way to know for sure is to fit a better mechanical gauge (let me know if you find a nice looking black face one!) and see what it reads.

I was bidding on a HKS gauge yesterday but i didn't know what size it was so didn't want to bid too high, and missed out.

I'm going to try the TTC mod today as i've just seen how easy it looks to do! Although i'm very good at messing the easiest things up If it still only reaches 0.6 bar then i'm guessing its just a gauge which is no use other than ornamental!!

you wont get positive boost unless the car is under load anyway, it should read negative boost (vacuum) when idling too. As for the accuracy, do you have another gauge you can borrow ? How does it feel in the seat of your pants gauge ?

Thats the thing, i've never been in another standard TT. I've came up against a BPU TT on the road and his was a fair bit faster, but obviously its going to be faster anyway so that doesn't help

Well i tried the TTC mod today and it was boosting at 0.6 as well, unless you had it in a higher gear and put your foot down from

So i think i'll get a new boost gauge and see it that makes any difference.

Something sounds really wrong there buddy. Boost should be going up the way with the revs, not down the way.

Also, with the TTC mod you shouldn't see any boost till the turbo's come online at 4k revs.

Edit, i'm assuming you have the gauge connected to the right hose?

Something sounds really wrong there buddy. Boost should be going up the way with the revs, not down the way.

 

Also, with the TTC mod you shouldn't see any boost till the turbo's come online at 4k revs.

 

Edit, i'm assuming you have the gauge connected to the right hose?

Yeah sorry i explained that wrong ! What i meant is that if you put your foot down at 2000rpm it will show 0.7 bar when it eventually spools up at around 4000rpm.

In 1st and 2nd i think your boost is held back a little to help with traction. I know this is the case with the MR2 and i think i read that its the same with the sup.

In 3rd you should see full boost at around 4-4.5k. It should read 0.8 if stock, if not i would probably put that down to the gauge. I would try another one anyway just to be on the safe side.