turboblack2door

I've got a vitara engine for my 88 crx si and now it's come down to the manifold. I'm not sure I want to use a ebay log because I don't really care for them so I got to thinking about running a sinktrap with my holset hx35. I know the theory being the lenght of the runners with effect spool time as well as pipe diameter will effect the spool time as well so basically I'm looking for input from those who have had them or have them to see what worked or did not work for you. I have been searching like crazy for the past 3 or 4 days and not a whole lot has come up about spool time or performance with these setups so any input would help thanks

I'm looking at something similar to these 2
I kinda like this one best because it's divided and should help with flow but not with the home depot elbows off the manifold though
[img width=731 height=600]http://i174.photobucket.com/albums/w103/futurerider103/elephant02ha9.jpg[/img]

But i also like this because it would be stupid simple to make



This is more what I think i'd like to go after if I did it

TheShodan

iTrader: (14)

Umm. Check the FAQs in the forum under " which manifold is for me"? That'll give you what you need.

wantboost

iTrader: (2)

Yeah I'm a little confused as well. Are you looking for theory behind why the manifold works or are you looking for setup information how much power the manifold made? I can tell you top mounts do increase leg but over say a cast or log manifold will have considerable power gains at higher power levels.

if you're looking for pictures of fabricated manifold and practical application theory, then this needs to be in the welding and fabrication forum

turboblack2door

I'm just looking for info on the spool times if someone has used a setup like this with a holset hx35 before because i know it's laggy as it is but the last time I used one it was on a log and i wanna know if it is going to be around 300rpm more laggy or 1000rpm more laggy or what not. I'm not really looking for how much power the manifold made but if that info is available that would be great. From what I do understand is the factory mani's start chocking out top end but no info on what turbo that was on or how high in the rpm range it was

vtechjunkie

iTrader: (2)

When trying to pinch pennies, you find yourself in the beggars can't be choosers bracket. Manifold design directly reflects upon the spool time. In my experience Holset turbos like high boost pressures, and act the best with a devided manifold/housing. With the amount of design you will be putting into this manifold, you may as well make the entire thing to your specs. Or buy one.

wantboost

iTrader: (2)

And the way the holset behaves is directly tied to the turbine housing size. Do you know which turbine housing you have?

turboblack2door

12cm housing 7 blade. This would be a cheap investment and there would be no reason to make a manifold or have one made if all i need to make is an extention and find a free or cheap header localy or something. I have had a holset on my race car and i do know they like high boost pressure but I also know they take a bit to spool which leads back to my question about how long did it take to spool. With my old CSAddict log it would spool right about 4800rpm. I want to know am i looking 5500rpm or to high in the rpm range to do anything. BTW this turbo is the one that was on my racecar that went 10.83 @ 132mph

wantboost

iTrader: (2)

Well here's the thing I see people makes 600 horsepower on a log mani and I've seen people make 800 horsepower on a ram horn style. any manifold will make power it's just how efficiently it does it.

Here is something to think about it, do I need a top mount manifold?

I mean does your budget allow fourth or could that money be better spent on other areas of the car? Now at the top mount does have a few obvious benefits, it is easier to install and remove the turbocharger as well as service and inspect it, and while the return line may be much longer than other manifolds it is easier to route and you will not have oil drain issues as you would with a ram horn manifold.

turboblack2door

I've already got the expensive stuff bought. The setup is holset hx35, rc 1200cc injectors, aeromotive fpr, 255fp, hondata s300 in p28, lsd dragger clutch, tial bov and tial wg. There is money put into the setup I like the topmout setup for a couple reasons. 1. position on the block is not an issue. 2 you can put it anywhere to clear ps and ac if wanted. 3 less work to make dp fit through tiny space between block/oil pan and core support. 4. Big Ol' turbo chillin out up top looks cool to me

TheShodan

iTrader: (14)

Well, an HX35 on a 12cm isn't what I'd call "Big Ole", but again, the differences in responsiveness is heavily dependent upon the boost pressure and over all efficiency of a given turbocharger used.

For just an HX35, its a bit more preferential for the smaller of the mid-framed systems like you're describing. At 50lbs-51lbs/min, there aren't that many benefits to it, but that is up to you.

(I sure hope that with the pictures you're finding here, you understand that its the wrong way to make a "custom" topmount. There are much better examples available.)

Either way, here is that FAQ link you need to check out.

https://honda-tech.com/forums/forced-induction-16/why-top-mount-2152865/

turboblack2door

the holset is a big turbo in physical size

TheShodan

iTrader: (14)

Well. hehe as long as you feel its big, I guess that's the most important, right?

turboblack2door

Dont you know it

lsturbo33

What are your power goals? With a 12cm on a single cam it is more than likely going to spool after 5k. A 7blade hx35 compressor like you stated is more like 60lb/min. I really think you need to get a smaller turbine side if it's a street car if you want that thing to have any response.

scottdh20

twin scroll on the hx35 is the way to go....made my car 1000x more fun to drive. i also bumped down the runner tube diamiter on my setup to keep velocity to a maximum while still being able to flow the amount of exhaust gasses i needed to. so i dropped down to 1.25" diam tubing. (from 1.5") that and the twin scroll design i dropped 1000rpms if not more off spool time.

last year with an equal lenth ramhorn with a 4-1 flange and 1.5" runners i saw -8500rpm limiter
1st 0-5psi
2nd 16psi
3rd 22psi at 5500rpms

this year i have a forward facing manifold, runner length is about the same as the ramhorn, paired 1-4, 2-3 divided manifold, 1.25" runners - 8500rpm limiter

1st 16-18psi
2nd 22psi by like 6.5k...not entirely sure it just rips the tires off too quick, but iirc that was about what i saw at the track

if you do a sinktrap get a 4-2-1 ebay header as they are paired up 1-4, 2-3 and keep them divided with two wastegates.

wantboost

iTrader: (2)

The hole sets are not true twin scroll, they are simply a divided turbine housing which is very different from a twin scroll turbo housing.
I can understand why you would want to do a manifold like this, especially if you already have a 2 piece 4 to 2 to 1 exhaust header. It does save money that you would spend on a manifold but what you have to remember is that NA headers are made a very thin tubing something like 18 gauge which will not support the weight of your average turbocharger even with significant bracing and hey stand up time out to support the weight of the turbo you still run a very good chance of cracking the manifold.
there's a reason that most turbo manifolds are made out of schedule 10 pipe and not tube.

turboblack2door

5k rpm is where it spooled with a CSAddict log do I'm expecting at least that

I don't plan on keeping the car past next summer so if the manifold cracks i guess i can buy another on but i don't think it will fail that soon

wantboost

iTrader: (2)

Imagine running an eBay turbo manifold, that's about how thick the metal is... it won't take very long to crack. I'm not saying its low quality it's just the metal cannot take the stress and fatigue from all that weight and vibration

turboblack2door

My very first turbo setup was a Ebay tubular manifold and it didn't crack fire 6mnths(i was suprised as ****). We re welded it and braved and it was good until i got a diff manifold

LightningTeg

Yeah I would not use an Ebay header for the first half. Be much better off using the stock cast iron for the sake of reliability.

Turbo-LS

iTrader: (4)

Honestly if your not planning on keeping the car for long just get an Ebay cast log. It will perform just fine for the setup and with turbo compressor facing drivers side of the vehicle it will fit just fine and accomplish what your looking to do for a short period of time. Best of all there less than 100 bucks.

normally i wouldnt recomend Ebay parts but the cast logs do actually hold up. i had one years ago and it worked great but since moved on to better things

TheShodan

iTrader: (14)

The HX35/40 B8 hybrid series were 60-63lbs/min. The true HX35 A77s in 12 blade turbine/ 7 blade compressor wheel configurations were 54lbs/min at 2.9 pressure ratios at about 118,000 rpms, and that was with the 12cm housing.

He wants to know about these weird NA-to-turbo manifold conversions, so I can't be of anymore help with that nonesense creation. I'm just enough to let the OP do it. I just hope it worth the "temporary" setup that he's making it out to be.

All the best, babe..