anesthes

iTrader: (12)

Mocking things up. The ports/bolt holes on the AFR heads are 1/4" higher so the #8 tube smacks the bottom of the head. I guess I'll grind the head a little bit. Also, the tube hits the plug. I think I can just run a shorty 'header' plug, but I'm tempted to redo that tube. I don't get why it's run that way.

I'll have to cut my serp bracket in half. The T76 smacks the bracket, even with the idler pulley removed. I guess I'll get a 6 rib pulley to go on the tensioner and run the belt a little different.

The crossover snakes by the small 400 starter just fine. I think I'll put a flex pipe and a vband. I cut my y-pipe I had made for the SLP headers, and will use the cross over section to connect. I'm keeping the driver side SLP header since it's 1 3/4", and it's already bolted in, clears my steering shaft, and doesn't leak

-- Joe

anesthes

iTrader: (12)

Ground the head just a hair and the primary clears. The hot side just kisses the valve cover, so I may just give that a soft tap to clearance it.

Relocated some wires, and cut up the serp bracket.

I gotta check with clay what the hood clearance is like.

If I can find some stainless freeze plugs today I'll cut the wg flange off, close it up, and move it to the top like some of you guys did.

-- Joe

project89

iTrader: (1)

looking good so far u got the 76mm turbo?

anesthes

iTrader: (12)

Yep. And it just kisses the hood brace

I had to modify my valve cover a little with a BFH as well.

Dayco 89009 6 rib pulley worked great replacing the smooth tensioner. I just ground the arm down a little bit as it was rubbing the plastic part of the pulley. I suspect an 82" belt will work out quite well.

Overall, this project is easier than I thought it was going to be. Merging the WG back into the downpipe might be interesting but again, I'll use a flex.

Ran out of ambition today, but maybe tomorrow I'll cut the header and weld the vband flange on and move the WG flange to the other side. I gotta switch out the wire in my mig to the stainless roll I bought.

I cut up my y-pipe I had made for the SLP's. The donut gaskets leak a little. I'm tempted to just put a vband on the SLP header as well. I have a 2 1/2" braided flex so I'll probably incorporate that to keep the crossover from cracking.

The oil feed should be at 12 o'clock and drain at 6, right?

-- Joe

Street Lethal

iTrader: (16)

Looking good, get it done.

I cut mine up the same way Joe...;



Yes...

Confuzed1

iTrader: (4)

Wow Joe….looks like an interesting build you have going there!

Good luck with it! Just wondering since you didn't state it in this post…why did you decide to ditch the Procharger? Are you looking for more boost, and how much? How much power are you hoping to put down with this new setup?

-I know, a whole lotta irritating Q's…guess I'm curious is all…

anesthes

iTrader: (12)

Actually I drew up a short list:

1) Blowers make noise, specifically gear noise. Was driving me nuts
2) Belt issues, although I eventually resolved belt alignment
3) I had issues with mounting my hydroboost tank because of the head unit
4) To clear the hood, I had to mount the LS2 throttle body up-side-down. This caused some issues with the cable I had rigged. By swapping the throttle body to the other side I was able to flip the TB that now fit in the hood bulge and run a LS1 throttle cable.
5) I could sell my procharger, and use 1/2 the funds to pay for the whole turbo project.


I've also wanted to do a turbo for a while. My megasquirt is also an electronic boost controller, and it's winter so I need something to do.

I don't know how much power I'm hoping for. I'm hoping to not drive over my crank. I'd like to see the car hit 130mph in the 1/4.

-- Joe

anesthes

iTrader: (12)

Started reworking the #8 primary. Basically this thing is more of a log manifold than a header, especially now. The good things I can say is these headers are good material, thick, and welded well. But the design is dumb.

I gotta finish welding it up tomorrow, then start my downpipe. Then I gotta figure out where the heck to put the wastegate. I really wish they made a T76 with an internal wastegate.

-- Joe

junkcltr

iTrader: (1)

The header I have measured between .050 and .065 on material thickness. That is 18 to 16 gauge. It welded good. with 308L.

What wire did you end up buying for the MIG? 308?
Did you end up using your MIG mix gas or TIG Argon gas?
How did it weld with that setup? I have only used the TIG on this header.

I think once you run this turbo setup and see how much boost it makes at such a low rpm, you will wonder why you ever started with the SC. Not to mention it being nice and quiet. That is why I prefer them. Nice and tame until you stick your foot in it.
Being about to turn up the power with a quick adjust of the wastegate is another benefit.

anesthes

iTrader: (12)

Hello,

308L mig wire on my 240volt machine. I have a 5 ft tank of 100% argon, so that's what I'm using. I could have also used my TIG, but I didn't have any stainless rods and with zero experience welding stainless I wanted to go with the more user friendly welder.

I've found that stainless is tricky. If I turn the heat down I get splatter regardless of wire speed and argon setting. (set it at 30), if I turn the heat up I get a nice weld but I've blown through in some spots and had to make a second pass to fill a hole here and there. So I'm going between 50 / 75 amps and throttling my wire speed between 3 and 6 depending on what I'm doing.

I'm using solar flux type b on the inside, although the whole tube is turning cherry red when I'm welding it so I don't know how well that is shielding it.

Unfortunately I don't have enough bends to do my downpipe today, so I gotta wait until the Ubend I ordered comes in. Which also means I can't do my wastegate because I won't know where to put it until my downpipe is finished.

The #8 primary clears the plug now, but I can't get the header bolt in the hole. I gotta heat the tube up and dimple it a little or use a short stud..
-- Joe

anesthes

iTrader: (12)

Flange warped a bit. I ended up cutting the flange (like hooker does on some headers) so the #8 was all by itself. Heat it up and straightened it.

So stage ummm.. 1ish is done, primary #8 moved (twice if you can tell), wg flange cut off and plugged, crossover shortened and vband clamp welded.

I mocked it up on the car itself and it fits well. I can get to all the plugs, no risk of burning the boots, etc. Next I gotta fabricate my down pipe and then I guess weld up the wastegate flange. I'm dreading that part. I'm still tempted to try and put it on the turbo itself but I don't think there is enough room.

I originally routed the #8 down and into the crossover low, but it looked stupid and didn't provide any more plug clearance, so I moved it up top so it's more of a log manifold now.

What do you guys think?

-- Joe

Street Lethal

iTrader: (16)

Excellent work Joe, that is essentially the same routing I went with when I welded my #8 primary with my turbo system. It's looking really good, it's getting done smoothly...

- Rob

anesthes

iTrader: (12)

Thank you!

I gotta pick up another tank tomorrow. Welding the stainless with 100% argon is interesting, I tried a peice of mild steel and it just plain sucks. I need some C25 in the shop. I have rolls of flux core but I mainly use that for when I'm working out in a field or something and it's windy. It welds ok, but leaves a mess.

So hopefully by like tuesday or wednesday I'll have the downpipe fully fabricated and maybe get the WG flange done.

-- Joe

Confuzed1

iTrader: (4)

Sounds like you have something to do for winter now!

I never realized the Prochargers made that much noise....I know I've heard some of the blow-off valves make a bunch of noise at traffic lights. Trapping 130 in the 1/4 sounds pretty wicked fast to me!! OK...I'm done polluting you're post...just following in hopes I can learn more about these turbo builds. Most everyone around this area are running Prochargers, but turbos themselves are so much simpler. It's all the fab work it takes to install one that scares me away since I suck at welding...should be one stout motor when it's done....good luck with it!

project89

iTrader: (1)

put the header on the car and the turbo then put the wastgate 90* to the log part of the header it will work just fine

the ideal place would be to cut off the old wastgate tube and mount it stright out the front below were the old wg tube was on the outside of the bent that turns up twards the header flange

ex gas will hug the outside of the bend

anesthes

iTrader: (12)

I thought about re-routing the #2 primary lower into the log, and running the WG forward, but then I'll have 12 miles to connect it back into the downpipe.

-- Joe

anesthes

iTrader: (12)

This is one of OZ cheek's cast manifolds. I wonder if I could modify the chinese header to route the WG like this.

-- Joe

Orr89RocZ

iTrader: (20)

Run a good gate size with it 90 deg to log portion back closer to number 8, it should still work good there

anesthes

iTrader: (12)

I don't know what good size is, but I have a 38mm gate...

-- Joe

Orr89RocZ

iTrader: (20)

44-46 would be great but a 38 should do ok just run a soft spring to see how it controls boost. My old twin setup had the 40mm gate fed by 2 out of 4 cyl and controlled a 6 psi spring to 8.5 psi, so it wasnt bad even non optimal design

If you can get 5/8 cyl feeding a gate that should work

project89

iTrader: (1)

my twins are controlled by 2 38mm gates with 1 cyl feeding each gate , controls boost down to 5/6 psi

anesthes

iTrader: (12)

How do you guys calculate your target boost when sizing the WG spring?

Like, on a blower, I'll figure out my belt ratio so I'm not exceeding max efficient impeller speed at my max RPM.

How do you figure out safe impeller speed/whatever to keep yourself on the right side of the boost island?

Actually, let me explain this question better. Looking at the attached compressor map, and going by the magic rule of thumb of 10hp per lbs/min of air.

So let's say our target is 650hp, so we needs 65lbs/min airflow. Looking at the compressor map, I can't see how you draw a conclusion of what your target boost will be because I don't know it's relationship to airflow.

So if I go with a boost ratio of 2.0 that puts me between 70-75% efficiency @ 65-75k impeller speed. But how do I know that if I set my WG to 15psi, it will flow 65lbs/min ?



-- Joe

project89

iTrader: (1)

how much power does the engine make n/a? general rule of thumb is u will dbl power at 14 psi , but i find it on a good setup to dbl more around 9 psi

anesthes

iTrader: (12)

455hp at 5500rpm, and 520 foot lbs at 4000 rpm. Thats flywheel HP.

-- Joe

project89

iTrader: (1)

start with a 5-7 psi spring

anesthes

iTrader: (12)

Ok. Will Do.

Would be nice if this WG came with actual instructions and perhaps labels for the assorted springs that came with it. wtf!

http://www.ebay.com/itm/370958238595...84.m1497.l2649

-- Joe

project89

iTrader: (1)

did u buy that wg?

u can test springs with a compressor and regulator , valve should start to crack open at 2-4 psi below rated spring presure

anesthes

iTrader: (12)

Yeah that is the one I bought. Nice packaging, cool brand label, foam inside, well machined product. ZERO paperwork. Amazing huh?

I'll try that test out tomorrow.

-- Joe

project89

iTrader: (1)

honestly u should have bought the 4 bolt 44 or 50 mm wastegate for a few more bucks , im not sure a single 38 will control boost low enough in ur application , placement will deffinatly be key

other then that only way to know is to try it out

anesthes

iTrader: (12)

I'll weld it up with 2" pipe. If it's not big enough, I can cut the flanges off and weld 50MM flanges on it and swap it out after.

-- Joe

Orr89RocZ

iTrader: (20)

Airflow required in lbs/min = hp * air fuel ratio * brake specific fuel consumption / 60

Typically thats 9-10 lbs min per hp depending on setup. My car is closer to 9

Then you need to find absolute pressure required to make power.
(Air flow in lbs/min * intake air temp in Rankine * 639.9) / (rpm peak/2*cubic inches*volumetric efficiency)

Thats psia. Gage pressure is one atmosphere less, which is 14.3-14.7 psi less so subtract that

Then calculate pressure ratio by taking the above gage pressure required and divide by atmospheric

My car at 1300 hp or 1014 whp estimated with 11:5 air fuel at .58 bsfc requires 144.5 lbs min total airflow. At 90 deg f inlet 6400 rpm 401 inches and 1.01 ve, it works out to 24.5 psi gage required which is exactly what my dyno displayed. Thats a pressure ratio of about 2.74
Use that number on the map left axis

anesthes

iTrader: (12)

This formula isn't working for me. I'm coming up with .995

airflow 65lbs/min, 412 cid, 6200 rpm, 110 degrees, .90 ve.

I found this calculator:

http://www.rbracing-rsr.com/calcboost.html

Which seems to suggest for 650hp i'd need around 4psi of boost.

If I then look at 4psi (1.2 ratio) and then intersect it with 65lbs/hr I'm way off the island on the compressor map....



-- Joe

anesthes

iTrader: (12)

So again, using the calc here is roughly 650hp, 4psi, 68lbs/hr airflow.

Doesn't look like a good spot to intersect on the map.

-- Joe

Orr89RocZ

iTrader: (20)

My fault. Typo.

It should be rpm divided by 2 not times


For yours at 455 hp on motor alone, i get roughly 72 lbs min and 7 psi for 650 hp. P ratio of 1.52.

Big cube motors and low boost is low press ratios and that usually requires a bigger turbo spinnin slower. Alot of turbos shine at higher pressure ratios

anesthes

iTrader: (12)

So based on where that would intersect on the compressor map for the T76, how do you feel about this turbo ? Would you want it to be closer to the island?

-- Joe

Orr89RocZ

iTrader: (20)

Ideally you want to see operation in middle of the most eff island but you will be off to the right side, closer to choke and not as efficient as possible but it should work. Its hard to tell because thats not an exact map for the wheel. I use garrett maps alot since they are one of the only companies that seems to show maps for their wheels. Probably a larger 80 mm would work better but it is what it is

You dont have to rev it 6200 either. Can also cam back or short shift abit to keep pressure ratio higher

Jay_rich

iTrader: (4)

Did you end up with the on3 76mm? Sorry if its posted im at work and pretty well all photos get blocked at work. I think you are gonna find some issues with it on that size motor. For reference my buddy runs a TC78mm and is fighting issues which I think are from way too much back pressure.

His setup... 370 LS, TC78 (65mm turbine same as on3) and a 39mm gate.

He cant run less than 11psi due to the gate being small. Also the car is only picking up like 20-24mph on the big end. So something is telling me the turbo is chocking the motor out. He plans on swapping it out whenever he finds the time to wanna work on it again.

On your size motor I woulda went with the basic S475 T6 1.32A/R. They are decently cheap. However T6 turbo's make it a bit tricky to mount. I cut up a lot of my old Iroc to fit it in. You can fit it in the battery tray but then making a oil drain is a pita.

Also to add, go with 80lb injectors! I ran 60s on my old 370 LS with a T6 based 74mm turbo and the injectors were at 96% duty cycle at like 4700 rpm on 10psi.

Jay

anesthes

iTrader: (12)

Cam kinda flatlines at 5500rpm, but I need to pull 4th gear (manual trans) to 6200 to trap my desired MPH.

Optionally, I can go with a 3.42 rear gear vs the 3.73 I have now and cross the traps at 5600-5800 with the same MPH.

If I assume a VE of around 100%, but somewhat crappy intercooler efficiency (say 130 degrees?) and 5500 rpm I think we're looking at around 9.7lbs boost, or a pressure ratio of 1.65 @ 68lbs/hr. That still puts me to the right of the choke line.

Guess I shoulda put more thought to this before selecting a compressor.

-- Joe

Orr89RocZ

iTrader: (20)

These are rough calculations based on a map that isnt necessarily correct for the compressor used so its hard to say what will happen. The s475 map would be in range but some other designs its off.
You could be anywhere from 1.48-1.7 pressure ratio at 65-72 lbs at peak operation. If you look at peak spool rpm say 3800, you are at roughly 1.9 pr and 54 lbs min assuming near 700 lbft trq at 3800 which is feasible. At that point you are at peak efficiency through most of your rpm band. So you are going to have strong average power. Yeah it falls off abit near peak rpm but its gonna rip down low

I think it will be ok but the wastegate size is my only concern. Not optimal but its a good budget turbo build. Changing gearing would be good imo or tire size to reduce rpm. More rpm more backpressure isses will exist. Plus less rpm is better for oem block

anesthes

iTrader: (12)

All good points. I guess I won't know until I try it.

I'll do the WG tube with 2" like I mentioned earlier, and if it boosts too much I toss a 50MM on. I'm somewhat concerned about the 90* flange not being able to pick up enough from the log. I really like Oz's design better.

-- Joe

project89

iTrader: (1)

lmao one solution is to put heads on it that dont flow so well , then u will need to up the pr to make the power back and put the turbo plot back up were it should be

option 2 is to raise ur power goals and shoot for around 800-850 hp , wont get u into the most efficiant range of the turbo but will atleast get u back in the islands on it

option 3 is pull a ton of timming and up the boost to recover the lost power, could cause the engine to peak early and fall on its face at rpm though

i dont think any of us relized ur engine made as much power as it does n/a when we were helping u to size a turbo for this thing

Orr89RocZ

iTrader: (20)

I edited my above post. At midrange 3800-4800 its gonna fly. Pr will be 1.7-1.9 depending as ve changes alot at peak trq rpms

anesthes

iTrader: (12)

Hah. I could have got some cheap procomp heads, but I like my AFR 210s

Block would grenade. It's a 2bolt main stock 400 block from 1976, that I bored .060 over. Even at 650-700hp, we're risking driving over the crank...

This might be what we try doing. Maybe run 20 degrees in by 2500 and let the boost curve pull it through.

That's my fault. Should have explained what I had better.

It's a large cube engine, with some of the best heads money can buy and a free flowing 1206 port intake. Previously, when I had a different cam in it and different heads (AFR 195s) it made 550hp naturally aspirated. The AFR 210s flow way more than the 195s, but I lowered the compression to 9.3:1 by going with a larger chamber because I had picked up the procharger.

I guess I'll just try it and see what happens.

-- Joe

anesthes

iTrader: (12)

Hey Jay,

Yeah I did go with the On3 T76. I took it apart and it seems to be well built, although as we're noticing perhaps not quite right for my combo but we'll give it a try anyway.

I'm running 42lbs injectors right now and a walbro 255lph pump. I suspect I'll probably end up swapping both out. High duty cycles on modern injectors don't scare me.

-- Joe

project89

iTrader: (1)

i just bought some off shore heads for my car , they actually flow well as cast
250 cfm @ .500 out of the box with the 2.02 valve , with tons of meat for porting
400$'s for the pair bare , ready for assembly

they actually flow more at .300 then what my old heads flowed at .550

thats a good 25%+ gain over what i was running

the purchase also prompted the purchase of an hsr to match

im propably going to set them up with a 2.05 valve with some mild cleanup and run them as is
just wish i knew i was getting them before i ordered my cam , cam was great for my old heads but lacking in the lift dept for the new heads

anesthes

iTrader: (12)

I had to get gas so while I was at airgas I picked up a tube of stainless 308L rods for my tig. I think I'm going to try and tig the WG flange. Mig heated up the pipe quite a bit and the welds look kinda crappy.

-- Joe

project89

iTrader: (1)

i wouldnt trust mig on stainless turbo headers

when i built mine out of 316L and 321 , i didnt have anyone to hold pipes for me while i tacked them witht he tig , so i put a small mig tack on them and then tacked in othe rplaces with the tig and ground off the mig tacks

anesthes

iTrader: (12)

Structually the welds seem fine. I tested on scrap first, and cut it in half and penetration was good, no visible contamination of the weld.

The problem is, it makes a ugly weld.

-- Joe

junkcltr

iTrader: (1)

Turbo size was talked about back in post 19 & 20. It was known to be undersized, but with that header you didn't have many options. That thing is gonna spool around 2K rpm I think. Should be a lot of fun.

Not sure why you didn't cut off a few lengths of the 308L MIG wire and wrap together and use that as TIG filler rod.

Looks great so far. I would do what you are doing. Setup for 50mm wgate.

anesthes

iTrader: (12)

I don't think that at the time my understanding of 'undersized' was as complete as it should have been. I'm not so much worried that the turbo won't make peak power as I am worried about it overheating, or spinning too fast. I assume from what I've read that anything to the right of the 'choke line' is bad news bears... ?

Hrmm. I hadn't thought of that.. You coulda suggested that last weekend

Thanks. I'm gonna do 2" pipes for the WG, that way I can weld a 4bolt 50mm flange later.

I think I'm gonna run this for now, and maybe buy another header and re-work it. Cut the turbo flange off and move it forward and lower. Put a WG on the end of the log. Since I have no AC, there is absolutely no reason why the turbo shouldn't be in FRONT of the engine, rather that stuffed beside it. A bigger unit would fit, and it wouldn't rub the hood brace/valve cover like this does.

I wish I could buy just the header, rather than the 'kit'. It's actually a nice starting point. Then again, I guess building a log isn't exactly rocket science is it...

-- Joe