Dats Boost pulley question and gauges?

[DatSRBoi]

Ok Ok. I read a few post awhile back about members having boost gauge issues and how they resolved it. Well I finnally hooked up my boost gauge today and at idle its on VAC 20! Which Im guessing is normal and pass 20 is too much.When I floored it, it only said 2 to 3 at most PSI Boost. I have a PSI gauge not bar gauge and everything is tightened. I was told I have a 4psi pulley by the guy in this forum who sold it to me... But on the pulley it says TRD 3.4.

Whats going on? Is this why Im loosing to cars I shuold be close to?

This is the gauge I have.

[dominoSLEV6]

May friends procharged mach 1's boost gauge reads quite a bit of vaccum too at idle. His pulley was supposed to be 8 lbs but he was only registering about 5.5, somtimes there's issues with things like that, I don't think there's such thing as a 1/2 psi pulley, lol, but anyway maybe the ocnnection is just a little bad or something I think that was the problem with his I don't know if he's gotten it fixed yet, but I wouldn't panic over it.

-chris

[DatSRBoi]

Ok I read it wrong. Its going up to the second mark which means 3PSI... But it only gives me that in pass 5,000RPM I think. Somewhere around there..

The pulley has these letters and numbers on it. TRD-3.4 .... Does that mean I only get 3.4 PSI? What happen to the 4

Can someone teach me these numbers again?

[CASTRO]

ive got me a TRD pully that reads 3.2inches. I read somewhere that they used a slightly smaller pully for more power but didnt rename the PSI

[Akfahad]

I had the same experience when I changed my stock pulley to a 6lb pulley. It said "TRD 3.4," same as you DAT. My first reaction was WTF too, but I went off of what my boost gauge told me and whenever I floored it, it always read 4lbs. I didn't really think anything else about it since I was changing pulley's, but I would still like to know too.

[dominoSLEV6]

More about my buddy's mach FWIW, he doesn't make boost without WOT.

-chris

[DatSRBoi]

TRD 3.2" -------------2.5 - 3 PSI
3.0" -----------------
2.9" ------------------5.5 PSI
2.8" ------------------6 PSI
2.7" -----------------
2.6" ------------------7 PSI
2.5" ----------------
2.4" -----------------8 PSI


This is what I found at some site. Even then Mines says 3.4 and boosting only 3psi.

[eyedea]

You are right. when I installed my supercharger. I went straight to the 5.5 pulley, which indeed does read 5.5 lbs of boost at max. Due to unavoidable circumstances, i had to switch back to the stock SC pulley..(the "key" on the SC which i bought used wore out...)..

My TRD boost gauge cannot be wrong for the max boost is around the 3-3.3 lb range...

[DatSRBoi]

You are right. when I installed my supercharger. I went straight to the 5.5 pulley, which indeed does read 5.5 lbs of boost at max. Due to unavoidable circumstances, i had to switch back to the stock SC pulley..(the "key" on the SC which i bought used wore out...)..

My TRD boost gauge cannot be wrong for the max boost is around the 3-3.3 lb range...

So your gauges are telling you the right boost right?

[eyedea]

You are right. when I installed my supercharger. I went straight to the 5.5 pulley, which indeed does read 5.5 lbs of boost at max. Due to unavoidable circumstances, i had to switch back to the stock SC pulley..(the "key" on the SC which i bought used wore out...)..

My TRD boost gauge cannot be wrong for the max boost is around the 3-3.3 lb range...

So your gauges are telling you the right boost right?

Yes. The so called 4lb pulley registers much less boost than 4 at full throttle..

[DatSRBoi]

Dam... Time to find me a 5psi or 5.5 pulley... 3 isnt cutting me much.

[thakidd]

mine reads 4 on my trd gauge.i have a 6lb pulley if u want it dat...

[DatSRBoi]

No thanks I pass on that. 6PSI is too risky. I want to, but haha The pain to tune and keep it safe is too expensive for me right now.

[808Camry]

What size fitting did you use, I still haven't hooked up my boost gauge yet.

[CASTRO]

My 3.2 TRD stock pully reads exactly 4psi on the TRD gauge I have. Going with the EBC and updated hosing it bearly touched 4psi at high RPM.

After I bypassed the EBC by re-doing the hoses straight to the actuator, I can hit 4psi and sometimes it spikes to 4.5 easily.

Read up on Astro's problem about the actuator staying partially open at WOT. I believe he said something about getting only 85% boost.