Lowes boost-controller installed

TexasAlltrac

New member
Well, I followed the instructions exactly for the home-made boost controller for my st165.

I spent around $20 all told, took 5 minutes to install, 5 minutes to adjust, and I am done. Finding a ball bearing was the only real challenge. Everything else was at Lowes and Autozone (vacuum hoses)

Stock was .5BAR. I set it to .7BAR and have no problems. I tried .8BAR, but the fuel-cut kicked in and then it would not boost past 4psi without cutting fuel till I turned the car off and restarted and set back to .7BAR

World of difference though from 8psi to 10psi. The car is much faster.

Thanks to whomever figured this trick out and posted instructions!

Only advice I can offer to anyone doing this is: start out with the spring having no tension at all so you will be at stock boost. Start adjusting from there there at 1/8th turns (or less) of the bolt till you get where you want to be. Very small adjustments can make a huge difference, so be careful.

Also, get a boost gauge before starting.
 

jlcelica

New member
when i built mine i had a really bad boost spike after boosting over 10psi for some reason. I found the ball bearing needed at a bicycle repair shop for a nickel a peice.

Nice to see another 3s powered car in central texas 8) . Most are in houston or dallas.
 

TexasAlltrac

New member
Yup...not many Alltracs in central Texas. I probably have the only one in Austin and I had to go to LA California to get mine. Most dealerships here have never even had one in for service since the cars were sold new. I am glad I am able to turn all my own wrenches.

If you think we could draw a crowd, we could have a TX Alltrac meet sometime. I would be willing to help organize one.

Back on topic though:

I drove around for around town for about 20 miles tonight after I upped the boost to .7BAR with the Lowes controller.

The extra 2psi really unleashes the st165 (along with my other mods). I can get to the end of 2nd gear from a dead stop in just over 5 seconds ( was 88 degrees outside with massive humidity)

I do have some boost spike (to around 12psi, followed by a fuel-cut) if I do not let the car warm up properly after sitting for an hour or so, but it goes away after a few minutes or moderate driving and I restart the car.

The main problem I am facing now though is that the clutch (stock) does not want to hold in 3rd through 5th when at full boost (which comes on at around 2900 rpm). It is still very drivable on the highway and around town though, so no worries till I want to track the car. 1st and 2nd will get me to highway speed fast enough on their own. I will probably swap the clutch this winter if I can find or make an engine hoist.

My other mods, performance or otherwise, are: A fabricated cold-air ram funnel behind the airdam with a 4" pipe up to the cone filter, a cold-air box, intercooler heatshielding, hollow pre-cat, 2.5" cat-back, autometer boost gauge, KYB struts and shocks (fronts need replacing), springs (dont know what kind), and Hella H4 headlamps with 110watt bulbs.

As far as I know, the turbo and internals are all stock, but some tuning was done to the car before I purchased. The turbo is in too good a shape for 158,000 miles to be original for one thing.

So, the boost controller works and works great!

One other thing before install that I feel is important is that I spent a great deal of time fabricating heatshielding and running cold-air piping to lower intake temps prior to upping the boost. Without the cold-air mods, the extra .2BAR would not have made as much of a difference as it did, and the engine would be more at risk.

But now...the clutch. Anyone in TX have an engine hoist I can borrow for a couple of weeks?
 

SLC Punk

Member
Did you use one or two ball bearings? I have had mine installed for over a year and it has never spiked. I used two balls, one on each side of the spring. The bike shop gave me the bearings for free. 8)
 

TexasAlltrac

New member
I used one bearing.

I fixed the spring on the bolt-end to ride against the adjustment bolt in such a way that it would not bind up which could be what would cause a spike in a single bearing controller.

I think my boost spikes have to do with pushing the car too hard when it is cold and the charge temp is way low. Once it has warmed up, it is fine.
 

shoteh

New member
when I got my alltrac it came with a MBC and no booste gauge but I feel fuel cut a lot. What would I need take out or connect if I wanted to take out the MBC and make it stock. I dont want it on till I get a boost gauge for it. thanks
 

TexasAlltrac

New member
>when I got my alltrac it came with a MBC and no booste gauge but I feel fuel cut a lot. What would I need take out or connect if I wanted to take out the MBC and make it stock. I dont want it on till I get a boost gauge for it. thanks

Number one, turn the boost down to where you do not get fuel cut anymore. That way you keep much of the extra horsepower, but do not have to worry about the car throwing out the anchor when you least expect it.

But anyhow, in order to remove:

What kind of boost gauge is it? Do you have a picture of the engine bay from the radiator to manifold to turbo to airbox you can post?

It should be pretty simple to remove actually depending on where it is located in the engine bay. It should be very close to the front-driver side of the intercooler.

You will need 4-5 inches of large vacuum hose to put in its place. Get some small clamps too to snug it all up.
 

shoteh

New member
sorry I dont know what kind of mbc is it but here are the pix of it so get you an idea...

P1010027.jpg


P1010032.jpg

the hose I'm holding leads to the turbo but the other one goes too deep for me to see without taking off things

P1010029.jpg


I've tried turning it all the way without any pressure to the springs but I still get fc. is there any other reason why I can get fc?

also there is a switch under my dash which I dont know what for but It's not for the mbc is it? i didnt think there was a switch for it but it its wierd because when its switched on the car doesnt start. but off its fine
 

furpo

New member
im have made mine but yet to install it. im going to get rid of the standard dump pipe and exhaust first. we don't have the same fittings over here so i had to compromise so i am using a lot bigger ball. it all works fine testing it with the air conpressor so i carn't wait to see how it goes.

roger
 

InitialD93

New member
switch is prolly a kill switch for the battery so no one can steal the car... keeps ppl from just jumping in and taking off.
 

shoteh

New member
sorry still confused about what wires to take out, connect, buy, etc. am i suppose to take out the mbc and connect those two wires going into it? sorry noob at this kinda stuff
 

TexasAlltrac

New member
great pics

Just take that brass thing completely out and either couple the hoses together or replace them with a single 4" to 6" vacuum hose plugged into the same locations. Your car will then revert to stock boost settings that are pre-set in the wastegate actuator module which I think will be 10psi for an st185.

The boost controller you have looks like a home-made old-school DSM Home Depot recipe (pre-Lowes).

When the time comes, you can build your own that will far exceed that one or go with a pre-fab from Greddy, et all which will do the same thing.

Very clean engine bay you have.

My Alltrac is red too!!
 

shoteh

New member
thanks I like keeping my engine clean. Im sure you and most trac owners do also. yea too bad my red is fading :(

thanks for the help. I took some stuff off and found out that the previous owner didnt take out the VSV hose leading to the wg and so im guessing thats what is throwing in the fuelcut. Im going to get some plugs for it tomorrow and plug them, hopefully this solves it. I think im supposed to plug both sides but i remember reading somewhere that you get less lag if you only plug the vsv side and open the wg side. dont know whatcha guys think?
 
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