Gettin back into it

[petew]

Your best bet is to ask a local turbo specialist. It might be cheaper to use what you already have. Or maybe not, but my hunch tells me blow through would mean a whole new carb set up for that purpose.

[buguy]

Yeah I don't know that there is a local specislist. You'd be surprised living in the home of the Daytona 500 that there isn't much of that sort of thing around. I don't even think there is a decent machine shop around here.
I may just give go pop shop a ring and see what they know. I guess I'm just not knowledgeable enough to know if it's even the right turbo for me so I'm not sure about putting money into this one.
Also I kind of like draw through. I think it's a good looking and sounding set up.

[petew]

Go to a local race meeting and talk to the guys in the pit area. They'll be able to hook you up with someone who can help. That or look up local diesel experts. They all use turbos, so they'll know someone who fixes them.

[buguy]

I hadn't thought of that. I do know a good diesel place.

[buguy]

I didn't want to start another thread so since it was mentioned here I figured I would add on. I did some searching on the carbon seal for my T3 and found it seems by the time I get a carbon blacking plate and seal it's going to cost $250. That's way too much for an old turbo in my opinion. Something i hadn't thought of is how pulling oil would add it to the fuel possibly causing it to foul. So I guess my options are:
Deal with it
Get it carbon sealed
Replace the turbo
Go blow through
I've really never been able to find advertised turbos with carbon seals besides Lowbugget. If anyone has seen them I'd love to have a link. Replumbing for blow through would suck but surely that would be the smartest option in the long run. I'd love to go efi but the cost is high and I would need to do way more education before stepping into that. Anyone have thoughts here?

[Clonebug]

EFI might look expensive up front but by the time you screw around with carb jetting and frustration it starts to look pretty reasonable.

I did carb blow through for two seasons and 7000 miles. While it did work and I had it figured almost out...I spent a lot of time and frustration on pulling the carb and rejetting when it ended up being a little vent extension on the fuel bowl that made everything work.
By the time that happened I was done with carbs since I had been gathering FI parts for two years and i had fried my clutch.
If you want to stick to 6-8 lbs boost then a carb is fine with a simple ignition setup. Staying at that level is really difficult due the the addition factor.
Once you get over 7-8 lbs you should have a high quality ignition control with boost retard and other features due to IAT's and detonation issues.

The nice thing about a MS ECU is that you can use it for ignition only while you want to mess with carbs and then you can shop for deals on FI parts while you tune the carb.
The MS ECU gives you the ignition control you need for higher boost.

There is that other Arduino (spelling) board if you can solder and follow directions....It seems they can be built for $160 .00.

I guess what I'm saying is that while it seems EFI is expensive.....doing it with a carb is not cheap either.

I spent about $1300.00 on my first MS-1 with EDIS ignition. It cost me about $350.00 to get it to ignition only.

There are parts you have to buy like intakes, injectors, coils, wires, sensors, fuel regulator, throttle bodies and other stuff but some of it you can source used.

The easy way is to buy it as a kit........at a premium cost.....the other way is research, engineer and plan a system and then go find the parts at junk yards and swap meets. Ebay is another source. You might have to buy stuff twice or three times due to a change of plans or finding out you bought the wrong thing.......... ......been there done that.


From my experience.....and you can read my build as it is all the good and the bad in there........is read, read, read.
My turbo experience is/was an obsession and I have a LOT of time into it. It's still not perfect and there are some quirks but I'm not happy at the easy 10 lbs......I want 15, 17, 20, 22, 25 lbs boost and experiment almost every week on something.

As for blow through.......there are many turbos around that will work great on a smaller engine and I have found the Subaru turbos to be an excellent choice. I have I think seven turbos in my garage now that I have picked up. They range from tiny to huge......well.... the huge one went to someone else who has even higher boost goals than me.......but less time........
The max I have paid for any of them is $75.00 and most I lowball at $25.00 to $30.00. The great thing is I can check them over for damaged compressor or turbine blades....play in the bearings....or any other issues. I can also measure the inlet and outlet diameters to make sure they are the size I want.

On a blow through system.......
Once you go over the easy 7 lbs......you need.
Ignition control = Boost Retard.
Water injection and/or Intercooler.
Welded 3rd and 4th gear transmission hubs at about 120 hp.
Kennedy Stage I or equivalent pressure plate with a good disc.
Higher quality brakes for slowing down from the 90 plus mph runs when testing boost......
With my buggy I'm through first and second gear so fast it doesn't have a chance to get a good load on for more than about 14 lbs boost. 3rd gear is where it really starts pulling hard!!!!
Good tires and wheels for a smooth ride.
A solid built car with good suspension to track well at speeds above the legal limit.
I have 275/60-15 tires in back that are hard to spin. If you have skinny tires you will probably have traction issues.


I know nothing about draw through and it's issues. I have seen a few at car shows but never one running.
I did talk to a guy that said his ran excellent but there was no hood on it and some of the cooling tins was missing so I wonder.
Many people say they run great but I have not seen any run to confirm or deny.
On theSamba it is said you don't even need a carbon sealed turbo for draw through so maybe your turbo will work as is.
All you can do is try it.
When experimenting with this kind of stuff you have to remember.......You are the engineer and the mechanic.

It's the challenge that makes it fun.......Make sure you have an understanding wife or no wife........


Man.....Aren't I a gas bag!!!!!!!

My time frame on my build started in Oct of 2009 and I gathered parts for 2 yrs before that..........is it an addiction or is it dedication?........that's where an understanding significant other comes in.

In the end the turbo and EFI is the cheapest part..........

It's worth every penny and I consider it a cheap education......you can't learn this stuff in school.

[buguy]

Thanks alot for taking the time for that. Good food for thought. I don't think pushing the stock engine much more than 10-12 psi would be a very good idea. So I want to get it working well while I save and gather parts for a whole different build.
My car runs pretty decent but I may be factoring in that I know none of it is ideal. I know the carb is wrong and the turbo a bit too big. Header is cobbled together. Of course the stock trans is never going to be good enough. I get a bit of smoke upon start up so I know that the turbo is sucking a bit of oil. And I really don't mind messing with the carb. It seems like I enjoy working on it as much or more than driving it. It really wasn't that hard to get the carb as good as it can be. It always starts up instantly and idles perfectly.. I'm considering trying a 600 cfm vac secondary carb just because we have a bunch laying around. I don't think the venturi is a whole lot bigger than what I have on there now. I have mechanical secondary now and its impossible to tune correctly for that. I tried disconnecting the secondary but it didn't like it. Fell on its face up top (no boosted power valve).
So I'm thinking I will get a different turbo that already has a carbon seal and maybe try a different carb. I have lots to choose from here. I even found a couple SU carbs on an old Datsun engine out back! But I still need to find a small carbon sealed turbo. New or used I don't see much out there.

[Clonebug]

I don't want to make it sound like I am a know it all because I certainly am not and I learn something new every day.......well... at least I try to.
If your system is working then don't start over on something new....just improve on what you have.

My engine puffs a little smoke on startup too so it could be something besides the turbo. If I were you I wouldn't worry too much about it unless you are getting serious detonation on boost and/or lots of smoke at cruise or vacuum conditions.

All I know is I drive the crap out of my buggy turbo or not and I have managed to put over 25,000 miles on it with a turbo and probably over 50,000 miles on it since I got it built.
That says something....I feel.

[buguy]

Thanks. I guess what's getting to me is that it doesn't "feel" boosted. I don't feel much of any real pull. I know it's asking a lot from an engine that made 50hp before. I can see the boost gauge creeping up but I don't feel it. I guess maybe my first step should be to do a check for leaks. Even at a meager 8 psi, losing 2-3 would be substantial. Could a guy put a port further downstream to see how much is actually making it near the head? Or maybe I'd be better off pulling the exhaust and intake and checking them individually?

[buguy]

Also I did some reading and see some guys out restrictions on the oil intake line to the turbo. I don't have it right in front of me and don't remember what I ran for oil feed. I know it's a pretty small SS line. It seems some guys actually use carb jets to meter the oil so they know exactly. Not that I would know what it even needs to stay cool in the first place.

[Clonebug]

My turbo is fed by an AN-3 or 3/16ths line with no restriction. It works just fine with it and has since the start. Most oiling problems are from the drain side. You need a large and straight drain to keep from having oil problems.
AN-10 or 5/8ths is what seems to work the best. That is what my Subaru turbos had and I have stuck with that with no issues in all the miles I have driven.

If you can't feel 8 lbs boost you have something wrong either with your ignition or you are running lean or maybe both.

Without an O2 sensor and gauge you are guessing.
The O2 sensors are so cheap now they should be a required purchase along with the turbo. The PLX setup I have is less than $200.00 and cheaper if you watch for their sales. It is a sweet setup and easy to install with no calibrations required. You can also daisy chain other sensors to the Multigauge if you so desire.
I added an EGT sensor to it since it was on sale for $49.95.....I couldn't pass it up.

At 8 lbs. you should have 50% more hp so it should definitely be something you can feel.

An exhaust leak is not going to make much difference because usually a turbo is capable of much more flow than an engine requires.

My wastegate duty cycle is at 52% for 22.5 lbs of boost so there is a lot more potential there for extra flow.

[buguy]

I'm glad you brought up an 02 sensor. I've been thinking about that but I have just a tiny little 90* for exhaust. Do I need to build a longer exhaust to put an 02 sensor in?
My drain line is super big and pretty straight, I don't think that is part of the problem. But I wonder if my feed line could be too much in a draw through situation. But that is something I can look at anytime. I know I didn't just throw it together willy nilly. I did pretty good research before buying anything.
I would think with a 450 cfm Holley I wouldn't be going lean. Especially with mechanical secondary forcing it even if it didn't need it. But an 02 sensor would tell me more.
I guess it's possible I'm making 75 hp, maybe just hard to tell since I'm already moving and its gradual.

[petew]

Innovate motorsports have an online manual for the LC2. It tells you where to mount your sensor in the exhaust. Look that up, but I have seen some very short exhausts with an AFR sensor right in the end. The the roadkill guys have that setup on their turbo Rotsun.

[buguy]

Yeah I think mine might be a tad short for that.
https://www.thesamba.com/vw/gallery/pix/1651058.jpg

[Clonebug]

Looks to me like you have enough carb there already. Why not work with what you have and see how it goes.

You could easily build a longer exhaust outlet by pointing it down and running it through the missing tin and under the bumper. Then you would have a long enough pipe for an O2 sensor.
Take my advice and get a PLX. It's fairly simple to extend the harness if it isn't long enough, in fact I have a 4 ft extension for one already in my garage.
They are self calibrating and you can get the 4th gen O2 sensor which uses the 4.9 version. The Multigauge will display any controller you add and also will display the voltage so if you have a voltmeter already you can just replace it with the Multigauge.





I can log anything with my MS-2 so it's easy to see when and where the boost comes on. You will need to see how rich or lean you are running at full load.... once you know and if you are rich you can just turn up the boost. It's quite simple to build a MBC out of a 1/8 inch brass tee, some nipples, a cap, a spring and steel ball.



If you are running rich....crank the boost........