Question: Are the AEM Tru boost's vehicle specific. Are they different from car to car ?

Same question another way: Will any AEM TRU BOOST GAUGE FIT MY EVO IX?

Thanks

 

so crack pressure and spring pressure is the same thing correct? should it be set at 12?

 

crack pressure and spring pressure should be setup for each car / turbo. You slowly raise the crack pressure until your boost exceeds the setting that you previously set wtih the duty cycle. This is the point at which your wastegage starts opening (not where it fully opens), I have mine around 7.3 or something. Make sure and look at your peak numbers by holding down the right button for a few seconds.. vs just trying to eyeball the highest number.. You might be spiking alot higher than you think you are. I spike to 23 and taper to 18 on a good day. Sometimes t he desparity is larger. My old forge held boost better and a friend has it in his car and you can see it in the datalogs. Mine taper to 200 his taper to 220 from a 250 spike.

The minus on the vaccum or some users not having the minus is due to AEM having multiple revisions of this gauge. If you dont have the minus you can send it in and get the minus free of charge I believe. Not an issue with me.

This controller has tons of taper and big boost spikes. I think for the next round of testing I'm going to use the AEM solenoid with the factory ECU boost tables controlling boost. (if the ECU driver ohm value is compatible, which it should be).

 

Some people have had MUCH better luck with the True Boost. I dont think it just spikes and tapers, I believe that it may not be set properly.

 

I don't think you have yours setup right man. There are a couple of different configurations based on your wastegate type and I have a feeling you used the wrong one. Either that or your spring pressure is way off.

At 56% duty cycle and 12 spring/crack pressure I spike to 20.3 and hold 19+ to redline. I need to go and get a re-tune so I can get up to 22 psi. I had some issues during my last tune that I won't get into, which is why I have it set as low as I do.

 

Well, just an update to this thread. I had been tuning the stock bcs system with pretty decent results and thought it would work great with the AEM solenoid instead of the stock solenoid so I went out and purchased 2 10ohm 1watt resistors and wired them in series with the AEM solenoid to match the stock solenoid's 32 ohm load. Well, it didnt work at all so I'm back on the truboost system until I can get a GM 3port solenoid ordered. I'm going to continue to work with it for a few days and if I can get it to perform as well as the stock bcs with solenoid pill removed (tuned in ECU Flash), then I'll continue running it but according to DLL it's down by at least 15HP at similar load / boost and seems to boost later. I'll try increasing the spring pressure (currently at 7.30) because according to my logs it's making peak boost a few 100 rpms later than the stock system.

There is only one way to set up the truboost that I'm aware of.

The solenoid goes in between the turbo and wastegate, I dont know how anyone could louse that up. Also it doesnt like having the filter removed and being fed back into the intake (tried that, and it made low boost and fluttered). I was thinking it's probably leaking air out.

The GAE and wastegate spring are the same values, just different versions of the same gauge. The one with the wastegate spring value also has the minus sign for vaccuum. Earlier gauges have a GAE value and no minus sign but they do the same thing. Other than the spring value you have a duty A and a duty B which are independant boost settings. Normal boost and race gas, or low boost and normal boost, or however you want to set them up. Lowering GAE or spring crack pressure reduces spikes and opens the wastegate earlier, Higher values reduce spool time but may result in spikes. I think other factors were causing my taper issues.

 

such as?

 

I am also having issues with the aem not holding boost at higher rpm. I also didn't realize that I would get different boost in different gears. Fourth gear is the most consistent for me, but in first and second the car spikes around 18 and then won't hold more that 15-16psi from 5500-Redline. At that same duty cycle the car spikes to 21.5 then holds at around 18-19 in fourth or fifth but tapers to 15 at redline as well.

I have the car set at 60% duty and 11.2 Spr if anyone has some advice for me i would appreciate it. If i have to do something else to handle the boost that's fine i just don't want to waste money on something else that will have the same problem.

 

Sounds right to me. 4th and 5th are higher load hence more boost

 

For one thing, I shortened my boost hoses and installed the solenoid near the stock solenoid. The hoses are only about 15" long now. Secondly, I've found a correlation between the mivec and boost. Also, rev limiters are not all set the same. If you take your IX to 8000 rpms.. its going to have taper. If you never go above 7 grand your not likely to even see the taper that I'm talking about.

The most annoying thing now about the truboost is the modulation of the solenoid. It's just not as smooth at releasing air as a MBC or even the stock solenoid is.

 

I just had experience with one of these and to put it mildly, I was disappointed. The problems I was haivng with boost spiking and then dropping off seem to be the norm with these controllers from what I am now reading. I wasn't even able to get consistent boost numbers in the same gear on repeated runs. To me that is unacceptable. Sometimes it spikes to 23 psi and drops off to 19. Sometimes it goes as low as 17 psi. What's the deal? If it is to hold 20 psi, the boost has to spike up to 24 psi or so.

 

what is your gas mileage and air fuel ratio? I have the true boost and the wideband gauge from AEM, just curious what kind of mileage I should be getting

 

why does everyone tune so low? I hold at around 23-24 lbs and spike at about 28 lbs, no problems so far

 

You may want to ask why you were tuned so high, instead. Have you logged the tune?

 

Anyone else have any more experiences they'll share about their Tru-Boost? How consistent is boost with this unit?