limit boost for town driving and lock out at Highway speeds

[buguy]

I JUST pulled off my T3 (.42/.48) 50 trim if your in the market. It was just a little too big for my stock 1600.

[Clonebug]

As Chip said....The load goes away once the power increases due to boost.....once it gets to high you have to let off which closes the throttle plate and decreases the boost back to vacuum.

[Buggsy]

Mr. Stockpiler, if you insist on "shutting off" your turbo for any reason, it is easy to do. At the collector, before the turbo, weld in an exhaust pipe and add an electric exhaust cut out. The smaller one you can find, the better. I think I've seen them 1.75 inch on an import site, but Summit and Jegs have the larger sizes. When you open it, the turbo will not make boost because you've created an exhaust leak so large, there is no energy to spin the turbine. You'll need a small muffler of some kind to quiet it down on the outlet side of the exhaust cut out. I would put your system together first, and drive it. As stated above, I think you'll find adding this is unnecessary.

[theKbStockpiler]

Thank you for all the replies!

I'm not quite in the market for a turbo right now but thanks anyway. Do you have an ad on the Samba for it?
What exactly is a volvo flange? Are they easy to adapt to?

It looks like a T3 should fill my needs but what donor car should it come off of that is the best to adapt to?
I was reading up on the A/R aspect of a turbo and have questions about it.

It has to be an abstracted formula that actually indirectly works,like when you do half the math and the outcome is relatively close. I understand the ratio between the compressor wheel and the inlet but including the diameter of the inlet makes no sense. The compressor wheel has to be sized to the housing really well or it won't work at all. I experimented with this with a simple blower motor so I know it is true with radial fans. With the A/R aspect the width of the compressor or turbine magically does not count???

Is this all of what compressor sizing is,the height of the housing; which must match the wheel, and the diameter of the inlet?

Thanks for your expertise!

[buguy]

I don't have an ad for it. It actually has already been scooped up. The Volvo flange is just a regular T3 flange.
Ive read on how to actually determine what turbo you need but it was pretty complex. I just went by cfm requirements I had, and picked one that flowed that. Actually what I did was determine the hp I thought was plausible and pick a turbo that at 70% flowed what I wanted. Then I had to figure out what was available second hand that would be affordable. For me it ended up being a Subaru turbo. I bought the first turbo off of what I read at the time. Information wasn't quite as available at that time. The T3 I bought was just a little too big for my stock engine.

[theKbStockpiler]

What turbo should I be trying to source? A T3 but from what donor car, A 2.3 mustang/Tbird or volvo? I don't see very many for sale on FleeBay or Craigs list so do most of them come from a PickAndPull?

As far as connections go like the oil lines , what should I look for? What issues are there with setting the wastegate if the turbo has a internal one?

Thanks in advance!

[rs58rag]

Look for a Holset HX30 turbo off diesel engines as well. ..I put a manual boost controller on and went from 8 lbs to 14 lbs no problem, the pull is awesome and boost comes on at 2000 rpm under load. When driving around normal, engine sees vacuum but when boost is needed, just step on it. Also, no carbon seal, just a .062" oil restrictor to turbo. This is on a 1914cc.

[Dan Dryden]

Hey Dan ,,Give him a 'Ride' sounds like he's in your neck-of-the-woods?
my 1915cc will cruise at 70-80 mph without boosting and town speeds also of 25-50mph,like said, it's all about the 'load'

I’m in the UK.
If you’re based in the UK theKBstockpiler, maybe we could meet at a show in the summertime.

[theKbStockpiler]

I'm in York but its New York,Central/Western NY to be exact.


So a parts yard turbo looks like the way I have to go at this point. The classifieds I have looked in only appear to be high risks at a high price.

It looks like I will have to make a list of originally equipped turbo cars that will adapt easily to a ACVW and see if I can find a winner at the yard.

If I want the turbo to spool late the candidate will have to come from a 2.3-2.5 I guess. . A little buffer for choke would be nice I guess.

If anyone can enlighten me on these aspects I would appreciate it.

-I would prefer a 'oil only 'turbo.
-Are chrysler turbos like from a 2.2 decent or are Mitsubishi's better?
-Are there any turbo's that are not worth the effort to clock or can't be clocked?
-What type of flanges are the best?
-Is one type of oil connector better than another, like the banjo?

Thank you for your expertise!

[Chip Birks]

I'm in York but its New York,Central/Western NY to be exact.


So a parts yard turbo looks like the way I have to go at this point. The classifieds I have looked in only appear to be high risks at a high price.

It looks like I will have to make a list of originally equipped turbo cars that will adapt easily to a ACVW and see if I can find a winner at the yard.

If I want the turbo to spool late the candidate will have to come from a 2.3-2.5 I guess. . A little buffer for choke would be nice I guess.

If anyone can enlighten me on these aspects I would appreciate it.

-I would prefer a 'oil only 'turbo.
-Are chrysler turbos like from a 2.2 decent or are Mitsubishi's better?
-Are there any turbo's that are not worth the effort to clock or can't be clocked?
-What type of flanges are the best?
-Is one type of oil connector better than another, like the banjo?

Thank you for your expertise!

Oil ony turbos are no better than turbos with coolant passages. Its pretty well established that you can run those passages wide open without issue.

OEM turbos are all built to last for 150k+ miles. They are probably all good assuming you size it correctly. There is the whole carbon seal thing to work around too though...

Turbos with built on wastegates are much more limited in their ability to be clocked. If you are willing to go with an external gate, your options open up a whole lot more.

Thick flanges are nice, 3/8-1/2 inch are pretty commonly used.

I have no comment on the oil fitting. Mine just have a NPT port on top and I run a AN fitting.

I really think you are way overthinking the whole insta-boost thing. It all comes down to your right foot. if you don't want boost, keep your foot out of it. 1-5 psi while accelerating, is nothing, just a little extra oomph to get you around a slow driver, or when merging onto the freeway. Take it from a guy who has turbocharged almost every aircooled VW he's ever driven(from mild daily drivers to full on drag cars to wild street cars). I've never had a combo that was too responsive or that drove in boost while cruising, I just don't think that is the norm.

[buguy]

Turns out mine is back up for sale if your interested. Turbo, flanges, exhaust with 02 bung, barb outlet fitting, and oil line. Has a little shaft play but didn't seem to affect anything. Last video before I pulled it off.
https://youtu.be/rCBaD4MKymc

[theKbStockpiler]

It looks like Mercedes turbo diesels have a T28 on them. Are they comparable to a T3?
As far as converting to a external waste gate, are they fully clockable then?

Thanks agian!

[buguy]

A T28 is a T3 compressor on a T25 turbine. As with all turbos you will need to know AR # (maybe it is 64?) to really know what they are.

[theKbStockpiler]

Is the t28 ment to spool earlier with more low RPM boost and fade on the top end?

A turbo calculator says I only need CFM in the 270-300 range so a T2 or a T25 will produce this but all of the 2.0's I read about that are not factory have something bigger on them. Do CFM calculators error on the low side?

[buguy]

If I had to make a generalization, i would say it would likely spool earlier than a T3. Again, not knowing the AR it's hard to say. There are different size T28's just as there are different size T3's.
The calculators seem to be pretty accurate but I think the numbers we generally put in arent. You are guessing at IAT numbers and I believe the efficiency is much lower than what you are probably putting in. Also at what boost do you need that cfm? Is it something you can realistically do?