EZ SBC turbo manifolds

[silicone boy]

As some of you know, my project took a detour when I decided, heck, why should the ricers have all the fun with boost? I decided to have fun with turbos-2 of them to be exact. In doing my research, I soon found out that the vast majority of twin turbo applications out there are on Ford Mustangs because you can simply flip over a shorty header to use as a manifold (you need to make an adaptor pipe, but it's very simple). I looked all over the GM parts bin and various header companies to find something that would work adequately, and nothing completely fit the bill. It seems that, while it looks like there is a lot of room under the hood for a SBC twin turbo, in reality the turbos and all the plumbing involved takes up a lot of room. The Turbomeister 383 twin turbo) had to make his own manifolds, mounting the turbos in front of the block. I wanted to mount them at about the midpoint of the valve covers, placing most of the weight behind the crossmember for better handling (again, the weight of turbos and plumbing is not insignificant). I thought about block hugger headers flipped, but every one I tried placed the hairdryers too high. I proceeded to make my own manifolds (actually had them finished) when I noticed that C4 Corvette LT1 manifolds would make great turbo headers with a little modification.

 

I simply cut off the stock flange and welded on a T3 flange as seen below. This places the flange just below the top of the valve cover, leaving plenty of room for hood clearance.

 

Now, my turbos are from a Buick GN, which has a 3 hole flange. Why would I use a T3 flange? I had some spare Ford T3 turbine housings that are about the same A/R ratio and they seem to work better me (they fit right onto the Buick compressor). Perhaps with a little work, I could have made the original Buick turbine housing work.

 

So after spending a moderate fortune on trying out various manifolds and headers for my twin terror project, I found a very EZ solution that should work very well. Don't they say the easiest solution is best? I should have thought of this earlier, but I'm not an engineer. I just made a lot of expensive mistakes so someone else doesn't have to.

 

 

[materchan]

cant wait to see how it turns out

[denny411]

The only reason I`m not building a TT383 is that I would like to have my car running this summer.

 

Once I have the car finished I will most likely start on a TT350 to put in at a later date.

 

I`ve already finished one car that I didn`t really get to drive. I`m getting real anxious to get one together and drive it for awhile.

[Turbo Meister]

This is not fair!! I had to plan and plan and fabricate; and you just found the perfect exhaust manifolds. Well, I realize you also spent much time just trying to visualize the perfect setup. Congratulations, the manifolds look great. How much clearance is there between the top of the turbos and the hood? You might have to attach some type of heat barrier to the underside of the hood. My exhaust manifolds are 2" from the inner fenderwells and I'm beginning to notice some slight paint discoloration from the heat. I'm considering some type of heat barrier at that point, myself.

Also, plan to reinforce the engine compartment sheetmetal to withstand the incredible and overwhelming engine torque complements of Twin Turbos. I noticed that my turbo engine torque has slightly tweaked the inner fenderwell metal of my Z. I'm anxiously awaiting the results of your first twin turboed drive.

Hanns

[Guest MistaFosta]

As some of you know' date=' my project took a detour when I decided, heck, why should the ricers have all the fun with boost? I decided to have fun with turbos-2 of them to be exact. In doing my research, I soon found out that the vast majority of twin turbo applications out there are on Ford Mustangs because you can simply flip over a shorty header to use as a manifold (you need to make an adaptor pipe, but it's very simple). I looked all over the GM parts bin and various header companies to find something that would work adequately, and nothing completely fit the bill. It seems that, while it looks like there is a lot of room under the hood for a SBC twin turbo, in reality the turbos and all the plumbing involved takes up a lot of room. The Turbomeister 383 twin turbo) had to make his own manifolds, mounting the turbos in front of the block. I wanted to mount them at about the midpoint of the valve covers, placing most of the weight behind the crossmember for better handling (again, the weight of turbos and plumbing is not insignificant). I thought about block hugger headers flipped, but every one I tried placed the hairdryers too high. I proceeded to make my own manifolds (actually had them finished) when I noticed that C4 Corvette LT1 manifolds would make great turbo headers with a little modification.

 

I simply cut off the stock flange and welded on a T3 flange as seen below. This places the flange just below the top of the valve cover, leaving plenty of room for hood clearance.

 

Now, my turbos are from a Buick GN, which has a 3 hole flange. Why would I use a T3 flange? I had some spare Ford T3 turbine housings that are about the same A/R ratio and they seem to work better me (they fit right onto the Buick compressor). Perhaps with a little work, I could have made the original Buick turbine housing work.

 

So after spending a moderate fortune on trying out various manifolds and headers for my twin terror project, I found a very EZ solution that should work very well. Don't they say the easiest solution is best? I should have thought of this earlier, but I'm not an engineer. I just made a lot of expensive mistakes so someone else doesn't have to.

 

[img']http://www.hybridz.org/phpBB2/album_pic.php?pic_id=2878[/img]

 

 

Pics dont work for me... I have a set of those headers, so I would be really interested to see the clearance, since I was scrapping my TT idea for a good single turbo setup.

[silicone boy]

Hanns,

 

You're right, I did spend a lot of time trying to come up with the "perfect" solution-there really isn't one. I have a pile of old manifolds off of E-bay that didn't work, some cheapo block hugger headers that were too tall when flipped over, and even a couple of fabricated manifolds that I just couldn't live with. I made a pair that I was going to bite the bullet and use. Then I saw these and my mind started spinning. The hood clearance is about an inch above the compressors, I think, and an inch and 1/2 over the turbines. Yes, I do plan on using some sort of heat containment device. I saw some turbo housing wraps that just appeared in the new Jeg's catalog, but it's not cheap--it might be cheaper than a new paint job down the road though. I also like these manifolds because they have a 3/4 inch threaded hole at the bottom between the middle exhaust ports-just perfect to connect an external wastgate to in the future if I decide to do that. Now I'll have to snake a downpipe between the manifold and the wheel well, but that should be do-able.

[silicone boy]

The only reason I`m not building a TT383 is that I would like to have my car running this summer.

 

 

Denny,

 

That's exactly why I'm not up and running yet. I figure I would have been running 6 months ago had I not been distracted by more power than I need. It's been a great learning excercise, though.

[DavyZ]

The only reason I`m not building a TT383 is that I would like to have my car running this summer.

 

 

Denny' date='

 

That's exactly why I'm not up and running yet. I figure I would have been running 6 months ago had I not been distracted by more power than I need. It's been a great learning excercise, though.[/quote']

 

Wow, there are a few of us...

 

I'm collecting parts for a single turbo V8, but still working on the V8 conversion It does not matter, heh, car is coming back from the body shop this Saturday, so I'll be able to start on it then.

 

I decided to go with a single turbo after talking to Scottie GNZ. I also have an upgraded GN turbo and a Turbonetics wastegate, etc etc. All on the back burner while I just get the carbed V8 done first *ugh*.

 

All it takes is time and money---2 things I don't have a lot of unfortunately

 

But, good job on finding the manifolds of choice!! I appreciate you posting them here too I also bought several turbo manifolds and I am convinced to go the route of unside down mounted short Sanderson's I bought from zfan a while back.

 

Davy

[Guest MistaFosta]

BTW, if anyone is interested, I have a pair of corvette lt-1 headers, of the style he is mentioning I would sell, they are ceramic coated...

[Guest the_dj]

How much would you charge to make me a pair of those?

 

I shall be the copy cat and follow your lead. I have 2 stock 280ZX turbos, but they are not in the best of shape. One needs a basic rebuild (seals, etc.) and one needs a complete reuild + one of the housings (compressor I think)...it absolutely grenaded. Anyone have any idea how much it would cost to bring the two of them up to proper working condition?

[Guest the_dj]

Seems like I can grab a pair of stock GN turbos in good shape for under $300. How much are the Ford turbine housings?

[silicone boy]

DJ, I'm buying up every LT1 manifold I can find, so I can set you up with some for a reasonable price if you want. PM me if you are interested and I'll get to work on some. As for the Ford housings, you want ones with the .63 A/R ratio (from a manual transmission Turbocoupe, SVO Mustang, Merkur XR4Ti). They fit right up to the Buick compressor. On E-bay brand spanking new, they run about $99. You would also need to get the exhaust elbow, or a swingate for the exhaust side that is Ford specific, which is about $79. What I would do is get a piece of @#$# used Ford turbo (manual only) cause it is a lot cheaper.

 

By the way, another thing I like about the Vette manifolds is they come with a real nice aluminum heat shield to protect surrounding components such as wires, etc.

[Guest the_dj]

How far along in the project are you? We should set a conversation between me and you where we can go over some different ideas. I've done quite a bit of work on my project (to no avail, and I really quit the project). Your work has pushed me a bit again, so we'll see where this goes.

 

It really seemed like everything set me back. I don't have a lot of time right now, but I'll be back in this thread later (probably tonight) to detail some of the problems I was facing. I have a lot of questions.

 

I really really really want to see what you can make of this (really, you've made wayyyy more progress than me) project. Of course, I'd love to say "we" made of this project but I think we all know how [un]true that would be.

[Guest tyrfryr]

i wanna play tt small block chevy~ lol. im tryin to go through he details of my tt350/400 swap. good luck and thanks for the header idea!

[Guest the_dj]

OK I'm back.

 

Here's a rundown of some things I tried (quite unsuccessfully)

 

Turbo placement: I had a number of troubles in this area. A few things "made up my mind." I had heard of people using their block huggers in stock or only slightly modified form and bolting the turbine on the end. I wouldn't do things this way if I continue with the project, but it seemed the most promising at the time I was working. Upside down, it placed the turbos through the hood...definately a no go. The right way, the turbos were actually in a good position: not too low and a decent fit with no wires or paint nearby to damage. I also considered a style of header to place the turbos right over the valve covers or in front of the block, but I didn't know how close it would put them to the hood and sides and didn't want to risk damaging the paint. I also have tall valve covers now which were a poor choice on my part. Hindsight is quite clear once again. If I continue with the project I'll be replacing the valve covers.

 

Oil lines: this is actually the one area I had nibble of success with. I created a proper set of lines and still have them ready to connect to the turbos should they ever go in. The main problem with the situation was the elevation of the turbos. They were too low in the engine bay to use gravity for the return line. Oil pumps are a serious matter, and trying to find a solution to this was where I stopped the project. The return line was the only questionable part of the height of the turbos: I couldn't be sure that they would stay above the level of the low part of the oil pan. The last thing I would want is them to break and drain the life out of my brand new setup.

 

Exhaust plumbing: Assuming I could get the headers to seal to the block (no luck this far and I'm still n/a) and I could create the small 1.5" adapters I would need to mount the turbines to the collectors at the right angle, "this wouldn't pose a problem at all." This looked like the most promising part of the entire situation and I didn't even complete it.

 

Intake plumbing: Yuk. There was some room between the block and the crossmember to run something, but I couldn't verify that there was room for room for 2 lines -->of sufficient size<-- to each of the turbos. That's four lines in a quite little place. This was another thing that made the placement below the engine a big question. I'm sure some proper fabrication would allow this to work.

 

Now I have some questions about your work with the headers you made. Have you done a mock up of the situation? Any placement of the turbo above the engine places turbine on the driver's (I think...maybe it was passenger) side VERY close to the strut tower. I also couldn't verify the distance from the hood with any such layout. Maybe things turn out different when working with short valve covers and I'd have to see how things looked with the tight style manifolds compared to the headers I was examining. What are you doing about the driver's side compressor lines? If both of your manifolds look the same, that places the compressor on the firewall side...not very beneficial for plumbing. More info more info more info!!

 

Ok I think I'm done for now. I'll be sticking around this thread for a while.

[Guest the_dj]

Doh, not done! What are you doing about the wastegate? Pretty critical part. Are you using internal or external, one, or two? If they are internal, have you checked the clearance of the actuators against the valve covers and the hood? On the driver's side it may touch the strut tower, but again I'm not sure. I know going external would mount a massive addition to the budget needed to complete the project. This is another one of the large areas of concern I'd need to be more confident of before I committed to the project again.

[Heavy Z]

You guys are blazing a trail into an affordable turbo system for the V8Z - this would really be a big step forward and would make for virtually unlimited potential.

 

Good luck!

[silicone boy]

Some thoughts and observations-I've had lots of frustrating time to think about this while doing the work on the motor.

 

-block hugger headers are generally too tall without modification

 

-mounting block huggers the right way and putting turbos on them in the bottom of the engine bay hurts oil drainage into the oil pan so you'd have to use an external oil pump. Also, it's harder to service the turbos.

 

-I'm sure about the hood clearance because I purposely chopped the manifold neck shorter by an extra 1/2 inch in case I want to use T4's in the future. They had barely enough clearance (about 1/2 inch) with the hybrid Buick turbos, and I can even chop the manifold shorter by another 1/2 inch if needed.

 

-I'm not so sure about the internal wastegate interference, but you can rotate the compressor housing relative to the turbine housing if you take the turbo apart, and you can mount the wastegate in any number of positions. In any case, the turbo is close to the valve cover (about 1/2 inch away) so there's plenty of room between it and the wheel well.

 

-It's not tight on the passenger side if you move your battery

 

-Yes, I may decide to mount one or both of the turbos with the compressor side closer to the firewall. That would make the downpipes exit in a forward direction and snake between the motor mounts and engine block. The air intake tubes could then would then be snaked down along the firewall into the lower, cooler part of the engine bay.

 

-As for intake and downpipe plumbing, I think I can get away without drilling large holes in the wheel wells like the Mustang guys do, but I'm open to it-it makes things a lot easier but I hate to do it

 

-If you want to try an external wastegate, you're not going to believe how convenient these headers are: They actually have a large hole between the middle exhaust ports that can fit a threaded pipe fitting. You can then fashion an adaptor for an external wastegate-it's like Chevy designed these things for me to hack up for turbos.

 

 

I'm going to mount the turbos on in a few days and I'll post pics and more comments as I find out more.

 

 

Also, Turbomeister-please feel free to chime in since you've done this already

[silicone boy]

You guys are blazing a trail into an affordable turbo system for the V8Z - this would really be a big step forward and would make for virtually unlimited potential.

 

 

I diverted my attention from "just" a stroker motor to a stroker turbo because I'm sick of all these ricers saying they can blow my V8 away. I got over the fact that forced induction and nitrous is cheating and started looking for solutions that are basically "junkyard" or off of EBay and can be replicated relatively cheaply-though it's not cheap for me 'cause I keep on making mistakes as a trail blazer. The Ford guys have this all figured out and have readily available, cheap parts. Us Chevy guys don't have very many cheap resources at all-hell Gale Banks wanted $900 for a set of custom cast iron castings that wouldn't even work without modification! All of the SBC turbos out there use custom made stainless steel headers that cost more than a motor, or require fabrication of a custom header out of heavy schedule 40 gas pipe. I was looking for more of a universal header, and the upside down C4 header should work on many applications. This was the big sticking point in coming up with a junkyard setup. It also helps that the Buick Grand National folks like to toss out their stock turbos in favor of upgraded versions. They are nearly everywhere.

 

I figure that in the long run, it will save people who want massive power some money because they don't have to decide between building a stroker, using a roller cam, swapping out higher compression pistons, etc. It won't matter because all you have to do is get a low compression 350 and crank up the boost!

 

I cannot be held responsible, however, for bodily harm that can occur in an 800HP car that weighs only 2800 pounds

[Guest the_dj]

What material are you going to use for your intake plumbing?