Problem with boost on the dyno

[Bobby]

i dont know how but more power to you. i couldnt go past 16 and stay steady so i just got the new 14 psi spring and we are all good now. i guess it all comes down to how good the boost controller is. i have the aem one maybe thats why

 

[PNR Welding]

i dont know how but more power to you. i couldnt go past 16 and stay steady so i just got the new 14 psi spring and we are all good now. i guess it all comes down to how good the boost controller is. i have the aem one maybe thats why

That could be it. I have to find a stiffer spring for that wastegate.

 

[Bobby]

i bet so. what boost are you trying to run.

 

[TurboPete]

I have a E boost 2. I dont read boost from the Manifold , mine is set up from the pressure side of the Turbo.
I always thought that you can only go like 10 psi's more then your spring pressure but like I said Im able to see more then that and I have a 8.5 Tial Spring .

Dont know if the Boost Controller has anything to do with it ?


Pete

 

[Bobby]

i think it does. my boost controller will only go 100% over the spring pressure so it is all done on % duty cycle.

 

[JeremyH]

I plan on using the eboost2 with a tial 38mm wastegate 8.5 spring and run 12-18 lbs on 93 oct. Does that sound about right?

 

[TurboPete]

I plan on using the eboost2 with a tial 38mm wastegate 8.5 spring and run 12-18 lbs on 93 oct. Does that sound about right?

You should be fine anything more in boost and it would be better to go with a v44 to handle the boost better .


Pete

 

[JeremyH]

You should be fine anything more in boost and it would be better to go with a v44 to handle the boost better .


Pete

Thanks pete, well i dont plan on going over 600rwhp on 93 oct, so thats when i would stop uping the boost. Im sure i wont need anything over 18lbs if even that. Judging by what others have been making i might get there closer to 15-16lbs.

 

[one eyed willy]

I plan on using the eboost2 with a tial 38mm wastegate 8.5 spring and run 12-18 lbs on 93 oct. Does that sound about right?

Just remember you can't go too big on the wastegate, I had a 38 mm turbonetics and replaced it with a obx 44 mm, it controls the boost MUCH better than the 38.44 will give you more room for error on placement, placement is a huge factor on how well the wastegate works.

 

[JeremyH]

Just remember you can't go too big on the wastegate, I had a 38 mm turbonetics and replaced it with a obx 44 mm, it controls the boost MUCH better than the 38.44 will give you more room for error on placement, placement is a huge factor on how well the wastegate works.

i know im just trying to avoid paying $200 bucks more for 6mm. I think the tial 38mm will be a good starting point and once i see how that works fro boost control i can go from there.

 

[one eyed willy]

i know im just trying to avoid paying $200 bucks more for 6mm. I think the tial 38mm will be a good starting point and once i see how that works fro boost control i can go from there.

It's alot more than just 6 mm, it's 6 mm around bigger, that's like comparing 2.5" exhaust to 3", don't sound like alot but when you consider it's 6 mm on the outside of the diameter, it's alot. I'm just trying to save you a little headache espeacilly if you trying for that much hp, all those exhaust gases have to go somewhere, 38 mm is fine for under 500 hp in my opinion.but hey....what do I know?

 

[JeremyH]

It's alot more than just 6 mm, it's 6 mm around bigger, that's like comparing 2.5" exhaust to 3", don't sound like alot but when you consider it's 6 mm on the outside of the diameter, it's alot. I'm just trying to save you a little headache espeacilly if you trying for that much hp, all those exhaust gases have to go somewhere, 38 mm is fine for under 500 hp in my opinion.but hey....what do I know?

Hehe, i hear ya man, thanks for the advice as usual!

 

[TurboPete]

I agree there's nothing wrong with going to a bigger gate it will handle boost much better and definatly eliminate boost creep.
I only said he would be ok with the 38mm b/c I had mine for awhile with the 38mm and made 610 rwhp like at 17 psi's and it worked just fine .
Granted the 44mm worked much better and flat lined the boost curve .
Either way it will work for that power level .


Pete

 

[JeremyH]

Damn wish the 44mm weren't so damn expensive, well i still havent bought the wastgate yet so i will look into this some more.

 

[Bobby]

every thing they have said is correct. think it is just a small price to pay more over the 38mm just for the safety. just think you could be buying the 60mm

 

[GI Joe]

Just spoke with ams 1000 support. This rule of the spring does not apply to the c02 controlled controllers...hence the reason for the c02...to put as much psi on top of the gate to controll all the boost you can throw at it up to 70 psi and still allow you to use the smallest spring possible ( for example for street use or launch purposes)

I do beleive this is Daves issue though the new spring will probably fix it...

AMS explained to me why mine is doing it on the dyno and said it will not do it at the track...sure enough its not doing it on the street...

 

[lito]

The wastegate size has to be related to the size of the waste.

 

[PNR Welding]

Well it looks like we found our problem. Here is a pic of a diagram that shows how the AEM tru boost hooks up and the problem is the way they have it hooked up. In the diagram I am using the External gate diagram. We eliminated the middle hose on the gate and have it running straight from the turbo to the solenoid and from the solenoid to the wastegate. AEM had you Tee into the turbo to go to the middle of the wastegate. Eliminate that hose and Tee and have it run straight from the turbo to the solenoid and from the solenoid to the top of the gate.

 

[turbotr]

The way they show it is the old standby "deltagate" mode. Like shown here:

If I follow the thread right, the boost dropping as you describe seems to suggest the controller can't get enough pressure to the top of the wg to keep it closed enough when the flow and pressure gets higher. So maybe you could try a stronger base spring or tweaking the spring adjustment in the gate (if it has one) to help the controller keep the gate closed.

Another thought, you might get a better result if you take the pressure tap from the intake manifold, rather than the compressor discharge. Since you have an intercooler the pressure increases there at the compressor outlet as flow goes higher, for a given set manifold pressure (to overcome increasing pressure drop across the IC and inlet piping with higher flow). Maybe this is helping push the gate open a bit with increasing flow, as you descirbe.

TurboTR

 

[one eyed willy]

Well it looks like we found our problem. Here is a pic of a diagram that shows how the AEM tru boost hooks up and the problem is the way they have it hooked up. In the diagram I am using the External gate diagram. We eliminated the middle hose on the gate and have it running straight from the turbo to the solenoid and from the solenoid to the wastegate. AEM had you Tee into the turbo to go to the middle of the wastegate. Eliminate that hose and Tee and have it run straight from the turbo to the solenoid and from the solenoid to the top of the gate.

thought you said you already took the boost controller out of the equation? also,in that diagram, whats opening the wastegate? if you run it like that then there is nothing opening the wastegate at all other than just exhaust pressure pushing on the wastegate spring,id be real careful on your first pull, boost SHOULD go thru the roof unless you have soooo much back pressure it will actually open it. did you ever check your back pressure?