I know a lot of threads mention that your boost will go up when you switch to a TBE. On my car this has NOT been the case. I have been running w/o the Xede for the past week. I only have the panel drop-in and the TBE w/HFC. I also put the pill back in the hose. With the Xede I used to boost to 22 psi on pump gas. Now with the stock boost set-up I logged four runs and the boost hits a MAX of 20.9. That is less than 0.5 psi above what a stock 05 EVO max boost (20.5). I have no boost leaks since I have had no problems boosting with the Xede on.

I do not know if others have logged their boost to test this, but the talk of more boost with a TBE does not seen to work at least on my car.

 

hi nj! in my car is used to boost 1.3bar which is about 19lbs when adding the the tbe with test pipe boost went up to 1.4bar which is about 20lbs.
do you think that you installed the boost pill the wrong way??

 

i think max boost stock for the 2005 models was 20.3psi so i think your find

 

Acutally just installing an exhuast will lower your boost slightly which is why you need to raise the boost back up to at least the same level or higher to realize the gains

 

That's mainly on IXs where the ECU will lower the boost to compensate, but on VIIIs, we usually see the boost spike several psi higher, thus causing fuel cut quite often when untuned. It may be more prevalent during the cooler months, but it is VERY common...

Also, as JRsimon said, stock boost is 20.3psi in case that .2 matters...

 

It is not easy to tell from a boost guage how high you are boosting. It is going to be hard keeping an eye on the gauge while going WOT. Also, boost gauge tend to be inaccurate. I know mine was and it was a good Defi D gauge.

We put the pill in the right way since we took it out from a stock spare hose that it was installed in.

 

Yeah it is 20.3 and not 20.5. I was 0.2 psi off

 

i think boost would rise more then .2psi if you added a testpipe.

 

I wonder what would happen if you reinstalled the stock exhaust
and then checked your logs.

I put my car back to stock and lost about a pound of boost on my gauge.



.

 

From what I read I was expecting 1-2 psi higher from the TBE. What I logged was a max of 0.6 psi more and this is the max of one run. The runs were done at the same place and the same time of day around 9:00 AM. If you average the max on all four runs you will get a peak of 20.58 psi. That will come out to 0.27 psi more than a stock 05 Evo (20.31 psi).

 

If I put my car back to stock, then the car should peak at 20.31 psi. That is what the Mitsu spec sheet says. Unless Mitsu is incorrect in their numbers. Manufacturers have published erroneous numbers before (Mazda, Ford, anyone....).

I do not trust boost guages for accurate numbers for these reasons:

1. Almost all of them are not MAP based. I was told that there is a MAP based gauge, but like big foot I have not seen it.

2. Your eyes will decieve you. It is really hard to accurately eyeball a guage while doing a WOT pull.

3. The display on a gauge does not go by an increment of one. On my Defi D every marker on the gauge was 1.25 psi. Strange, but that is they way it was. So what you see on the gauge will more than likely be deceptive.

 

That is possible, but I doubt it. There is really not that much of hp difference between a test pipe and HFC. But I will try it and see what I get.

 

i was also thinking that when you logged the boost i think it was on a 3erd gearpull?? maybe if you test your car in 5th gear you could see more boost??

 

Yes you will see more boost in the higher gears. But the people install a TBE and sya they are getting higher boost are mostly doing this in 3rd gear.

 

I have the Autometer (Cobalt Series). It is an electronic gague. Now Im a noob, but Maybe my setup is what your talking about because the "T" in my boost line then goes to a MAP sensor, then electronically sends the signal to the gague via wires, not directly from the vacuum line. Hope this helps a little..