My 2003 full bolt on evo stock turbo e85 doesnt wanna make more than 28psi of boost.. Boost is conteolled by gm 3port ecu controlled.does the 16g turbo have something to do wit this? I read people hittn 32-34psi

 

Sounds like a boost leak to me. What type of bpdv or bov are you running?

 

Metal 9 crushd.

 

Crushed IX DV are good for 26psi. If you look up any dyno graph with a crushed IX DV, you'll see it dip after 26psi, you need another DV.

 

Wouldn't a simple boost leak test tell if the DV was unable to hold the pressure? I'm curious.

 

He could just plug off the hole in the UICP where the DV sits and see whether or not it is the DV's fault. I doubt that it is the DV myself.

It is hard to say at what pressure level a "crushed" unit is opening at because no two DV valves are crushed to the same extent. DV crushing is a highly variable practise. The results vary from one unit to the next.

 

Yes it would.

I agree. Ever dv will hold different, you can also guss mod it to hold more boost but in all honestly, its prob okay.

Boost leak the car, preload the wga more, and Gus mod the dv if you are worried about it. Shouldn't have a problem hitting 30+psi. I'll tell you if you run more than 30, you will destroy the turbo quickly so I would go higher than that. Just my 2 cents.

Mikey

 

For test purposes, and to sort this issue out, I would bypass the 3-port ECU controlled boost management temporarily. Buy a couple feet of 4mm vacuum hose at the autoparts store and connect one end of this new hose to the nipple on the compressor discharge pipe(aka J-pipe) and the other end to the nipple on top of the wastegate actuator. Secure both hose ends to their respective nipples with hose clamps or zipties.

Now, to insure that you haven't created any new leaks, back track and inspect all the hose ends that may have been left open when you disconnected the 3-port setup. Plug any open hose ends with golf "T"'s or fine thread machine screws. Secure those temporary plugs with zipties too.

Remove the heat shield from the exhaust manifold. Loosen the backup nut securing the turnbuckle eyelet onto the end of the threaded actuator rod. Pop out the cotter pin that secures the turnbuckle onto the (wastegate)flapper valve's pivot arm. Pry the turnbuckle away from its home on the wastegate's pivot arm.

Rotate the turnbuckle adjusting it until the hole in the turnbuckle lines up perfectly with the peg on the WG's pivot arm. Note: At this point the length of the actuator rod should be adjusted so that the hole in the flat of the turnbuckle freely slides on and off of the peg on the gate's pivot arm without any need whatsoever to apply pulling force to help the hole reach the peg.

Setup in this way, your WGA should be controlling boost at about 10-12#. This is so-called, "base pressure". Setup in this manner take your car out for a WOT run in 4th gear to verify the boost level. Oh, please don't forget to reinstall the cotter pin that secures the turnbuckle onto the pivot arm first, duh.

After verifying base pressure then bring the car back in turn off the engine and let it cool down. Once it is cool again, then pop the cotter pin back off and pry the turnbuckle away from the pivot arm peg again.

Make sure that the backup nut is run down away from the turnbuckle far enough and rotate the turnbuckle inward toward the actuator cannister counterclockwise three complete 360* turns. This will shorten the overall length of the actuator rod. You will have to apply a certain amount of pulling force to get the turnbuckle back up onto and mounted on the peg on the pivot arm. This is normal. Reinstall the cotter pin.

Setup as I have described your WG should be preloaded to about 14#. This is about ideal for running a stock boost level of 18-19#. This may still to low for your particular application. You are wanting to run over 24# aren't you? Naughty boy!

For running higher boost levels over 22# etc, you may need to rotate the turnbuckle another coupe 360* turns. However, it is best to make these adjustments incrementally and exercising caution. Retest boost level after each rotation. Be patient, That is why I don't want you just rotating the turnbuckle 5 full rotations right off the bat.

I have found that ideally, at least from my point of view, and running as I do a MBC, that I like to set preload up to just 3-4# shy of peak boost level. So for example, if I am going to be running 25 PSI peak then I'll try to adjust preload to about 20-22 PSI. This level may or may not be attainable with the stock actuator though. Maybe 18-19 PSI of preload is more realistic for the stock WGA. Tou want to avoid the possibiliity of spring bind as this will interfere with full travel of the actuator rod and limit the flapper valve's lift.

You may find that the stock actuator is not going to cut it for the relatively high boost levels which you are trying to run. In this case we recommend an upgraded HD actuator such as the FP 18# unit for the VIII turbo, or the more expensive Forge Racing VIII actuator is also a good one.

There are a couple additional tricks that may work if you want to run higher levels of prelaod on the stock actuator. For instance, you can run w/o the backup nut behind the turnbuckle which will allow you to bottom out the turnbuckle on the actuator rod threads. Finally, you can saw a couple threads off the end of the actuator rod as well.

 

I thought the 8 16g turbo maxed at 25psi? Pretty sure you shouldn't run more than that.

 

It is capable of hitting above 35 PSI for brief periods. I think that TurboTrix used to do it. Curt Brown and various others ran the VIII 16G up to and above 32 PSI back in the dark days. So, it has been done before. Granted longevity suffers and you will be blowing mostly hot air....but it is doable.

 

Thanks for just saying i was wrong... Wonder who is right you or me? Lol becareful going against people that have been doing this for years and probably know wtf they are talking about when there is a big fat vendor under their name. And fyi, I can do 25-26psi on pump gas and the typical E85 car will be between 28-31psi depending on mods. No one single car is alike.

Newbie helping newbie equals fail. Take advantage of what the forum was designed to do... Which is for the expenienced to help the new guys, usually not the other way around sir. Lol

Mikey

 

Oh, and sparky is a well experienced guy too. You ***** slapped both of us.

Mikey

 

Mikey pretty much has it pegged:

1) Do a boost leak test.

2) Install a HD 25# actuator and increase spring pressure to 25-27 PSI.

3) Mod the IX DV or get something better.

4) I would add: Install a MBC for simplicity and ease of use during initial
setup of boost control parameters. The easier the better during
setup. Once you have everything sorted then go back to ECU control.

 

I took a look back at the opening post and noticed that the OP's Evo is a 2003. I am wondering if he still has the original, unported 9.8 turbine housing on his VIII turbo? If so, OP, you should at least order a fully ported 10.5 housing if you are going to be running over 30#.

What about the exhaust from the turbo on back? What does it consist of? Do you still have the stock O2 housing and DP? Are you running a cat or a TP? Ported stock exhaust manifold?

 

I was able to hit 32# on my stock 2003 turbo. I had to change bpv though. The stock plastic one could not hold the boost. With my ebc maxed out I could only hit 28. Once I changed it out I overboosted to 36 before I could get my foot off the gas.

I had to scale the duty cycle way down on the ebc to make 30.

The crushed 9 bpv should be good though...

I think that Mikey and Sparky have set outlined the normal diagnostic process.