I've tried my ebay boost controller with larger barbs and I guess the internals don't flow enough and it overboosts. Until then, I'm back to running 11.5psi, which I should also note turns out to be extremely fast.

I need a boost controller with at a minimum 1/4" porting throughout.

 

Your problem is four words in.

 

Most of the forum members here disagree with you. Regardless of where I got it, I need bigger ports.

 

doesnt the ebay mbc use 1/8" fittings? cant you just replace the barbs?

 

its it uses 1/8th

i changed mine this weekend to 1/4

 

Are you looking for mbc's only? I've got a Profec S here in front of me. The hose barbs are .24" OD / .17" ID and the solenoid ports are .331" ID

C

 

I have a Home Depot MBC with 1/4" barbs. I haven't used it yet, though.

 

Meh..just mount the damn thing directly to the compressor housing

 

I've already done this, but apparently the guts inside are too small.

This is the current state.

 

$100?

 

You can put passages as large as you'd like on there, the actual pintle/ball is not all that big. The air in the actual controller goes though a very small gap.

I have the standard McMaster "dodge style" (like the FM one) MBC, then another one I made out of the next size up valve. I was pretty sure it would help (it uses a pintle, not a ball).. But it doesn't seem to work any better or any worse.

I'll see if I can find some pics or something. With your external wastegate I'm surprised you're having problems. It's not a question of flow, unless you're getting spiking, it's a question of the leak rate of the wastegate/MBC.

I spent a while tuning the size of that hole, and it works well after messing with it.

 

Well, like I said earlier the 1/8" caused overboosting, so I guess its not filling up the chamber fast enough. Its doing the same thing when fed through the top port I suppose. I need a valve that dumps air faster.

 

You DO know how those work, right? There's a leak in the line, somewhere. One is included in the MBC itself, generally.

You need to find this leak and make it smaller. A single puff from your lungs would EASILY fill the wategate, so something else is going on. If you want to try to figure it out, I'd be happy to.

First thing is "overboosting" verses boost-spiking, which are you seeing?

 

Overboost from 11psi to 18psi at 5k rpm. I can take the boost controller out of the lines and it holds perfectly.

Its weird though because I should see no problem dumping the pressure because that goes through the bottom port. The engineer at TiAL told me to swap lto larger lines and that the reduction in the smaller lines can do weird things like this on the boost controller port.

 

No, but you can easily find used Profec's for $200. Tell your bitches that Daddy needs a few more Benjamins. Your backhand is still strong, eh?

C

 

I'd look for that leak. Think about it, if there was NO leak, you'd hit boost, the valve would open, pressurize the wategate, it would open, the valve would close, and that pressure would stay there, your wastegate would never shut. So, they put a small vent in. The vent might be oversized for the flow of the MBC.

Anyway, check out McMaster, they have lots of valves.

 

How difficult is it to change the spring out in the Tial WG? Do you need the adjustability of the MBC or do you just want to set and forget?

You're goal should be to simplify the car and not make it more complex by adding in EBC.

 

I've got the Greddy Profec B and I've never had overboost problems with it.

I picked it up on craigslist after watching for a few weeks for $100. It really has a large solenoid, so I'm sure flow isn't a problem.

 

The MBC's (take one apart and see) have, seriously, like 1/10th of a square mm of flow area.

If you can put in a spring in your wastegate its easily the best solution. Even shimming it isn't bad.

 

I agree, simplicity is superior. I could live with a profec-b though.

I want to use an MBC. I like to run the car on WG/11psi on the track for now. I also really like to play with 18psi on the street, or possibly the track if I feel the need to kill myself quickly or feel like hitting 150mph.

Sure I could put a stiffer spring in there, but I'd like to also have the adjustability.