typerturbo29

iTrader: (1)

Currectly have a 7 blade hx35 with the stock 12cm housing, looking to run a single scroll/open t3 top mount manifold with a 44mm gate. Any opinions on this? or would running a BW s360 / s366 with the Twin Scroll t4 housing (.91 a/r) with twin 38s be a better fit? Car will be driven on both street and track.

Goals 550whp 93 or race gas

Manifold is going to be built accordingly so no issue there focus is on the turbo, thanks

extremeracer

You can't really compare a HX35 to a S360 and definitely not a S366
The HX35 is similar to S256, and has a maximum compressor flow rate of 60 lb/min.

The DSM guys have pulled 550 - 600 whp out of the 7 blade HX35, running high boost pressure.

On a VW 2.0T (GTI), I've seen 520 whp at 5500ft elevation.

The 60mm HX40 is comparable to a S360, and offers more flow with a larger turbine wheel than the HX35. For 93 octane the HX40 would be a better bet IMO.

On either of the Holsets, try to make use of the divided housing and build a split pulse manifold, it really improves spool and response.

typerturbo29

iTrader: (1)

By split pulse manifold are you reffering to making the single scroll in the same fashion as a twin scroll 1-4 paired and 2-3 paired or just making the manifold TS?

As far as the difference between the turbos, this would more or less be the max of the hx35, would it not be better to say upgrade to the s360?

How much of a difference is there between the holsets divided t3(~.89 a/r?) and a TS t4 (.91 a/r) say for street use, im assuming the t4 would be better for track.

extremeracer

I would recommend a full "twin scroll" manifold with cyl 1&4 and 2&3 paired with a divider between them.

What engine setup are you going to be running ?

The S360 or HX40 will allow you to make power easier on 93 octane, the HX35 will need to run higher boost to make the same numbers, and 550 whp from a HX35 on 93 octane is probably not realistic.

The HX35's 12cm divided housing is nice for street/strip use. I run a HX40 variant with 16cm2 housing on my 2.0 litre VTEC, and its not lazy - but manifold design is pretty important.

Shadowcat

so I have a Holset H1C in perfect condition. it is simply the older model of the hx35. still able to make 500 on a top mount manifold? threshold is I believe 33psi on the H1C.

wantboost

iTrader: (2)

nope, won't happen on an h1c

typerturbo29

iTrader: (1)

Currently have a stock sleeved Gsr with pistons/rods, b16 head with ti springs/retainers, ctr cams.

Looking to upgrade to benson sleeves with same pistons/rods 81.5mm

Was also open to having a race gas and pump gas tunes. Have a friend that used this turbo made 533 on c16, but was a 2.0 ls/vtec with ramhorn and sigle 44, pretty much answered my own question I suppose

What about mating the Holset to a TS t4 housing and drilling the holes to make it fit. Really looking at the t4 because of more room to grow in the future if I wanted to.

typerturbo29

iTrader: (1)

Now another question, Would the twin scroll manifold really gain anything over the open manifold since the turbo is divided and not a true twin scroll?

TheShodan

iTrader: (14)

You mean the divided manifold for the divided turbo that's used? Nah.... won't make a difference.

typerturbo29

iTrader: (1)

so just a open t3 flange with a single 44mm would be plenty, or would a 60mm gate be better for 550whp goal ~25psi (I believe?)

TheShodan

iTrader: (14)

You're using a good amount of boost pressure where you're not bleeding off much excess boost, so a bigger gate isn't necessary, and actually can cause the turbo to behave in a negative fashion. in fact, since 550whp is going to be a real hopeful goal, stick to your 44mm, and you'll need more than 25psi to try to reach that.

typerturbo29

iTrader: (1)

Got you, so the bigger gate would be better if I was running low boost numbers.

TheShodan

iTrader: (14)

And a MUCH larger turbo..

Shadowcat

whats realistic on an h1c? with a 2.0l F20B?

wantboost

iTrader: (2)

What power are you looking to make.

also how do you like the f20b? I can get a full swap jdm blue top with a t2t4 LSD trans, wiring, ecu, etc for 1300 locally. was going to replace the f22a in my accord but I'm debating between the jdm blue top f20b and the jdm blue top vtec h23a, cost is about the same but I haven't compared aftermarket support for either motor

Shadowcat

I haven't personally driven the f20b yet. it was in my buddies eg coupe f2b and he broke flywheel bolts off into the crank. so long story short, I bought the entire running engine and tore it all apart, and am using an h22a4 crank. eagle rods, and custom 85mm weisco pistons. so a fully forged stroked f20b, im looking for around 450-500 when I finish getting the parts for the head. and defiantly go with the f20b if you want a high revving engine. but f your going to try and forge it. good luck. its a pain in the *** and expensive. but the h23a's are monster engines as well. lots of torque

torkh22a

What's the difference between a twin scroll manifold and divided manifold? Not asking about the turbo just the manifold.

wantboost

iTrader: (2)

No difference. the terms are interchangeable when referencing turbo manifolds. now the turbine housing is a different story. so many people throw around twin scroll as a marketing strategy and a buzzword. there's a marked difference between a divided and twin scroll turbine housing and the majority of turbine housings are divided, not twin scroll... but because the work gets tossed around so freely most don't know the difference. only two or three turbos/companies have true twin scroll housings.

the turbos off the EVO 3-10 are twin scroll, the BorgWarner EFR series has twin scroll housings, and the jdm STI turbos come in a twin scroll format. those are the only readily available twin scroll turbos that I know of

wantboost

iTrader: (2)

Yea I figured it would be a fun motor for my accord, especially given it is basically a detuned race motor. the rods and pistons are beefy and with the rods not having any nuts because the bolt threads into the rod makes them fairly robust. also the crank was designed for sustained low friction high rpm use with its small, narrow journals.

I do know the f20b has a fairly odd pin height compared to over f series motors but I think the k series pistons are still a direct replacement for them just like with other f series motors. I have heard of a lot of people having issues with dropping valves on these motors, mostly due to the smaller valve size and revised valve angles but it's sort of rare although I did read about one motor dropping 3 valves 3 different times fairly rapidly.

Plus you can't beat a mint low miles f20b with the LSD trans, wiring, ecu, axles, etc for 1300

Shadowcat

yes the f20b's have very different measurements when it comes with internals. and k20 pistons are not a direct drop in. k20's use a 86mm bore while the f20b uses an 85mm bore. since i was leaving the sleeves stock for boost, i wanted the most material left on the cylinder walls. there are only 2 engines that have pistons that will directly fit into an f20b without machine work :the f22A and the 4g63 Mitsubishi engine. both use the same bore, and the 4g63 uses the same pin bore and placement. however they just need to be ran 180 out. to achieve ~9.0:1 compression with the f22A pistons you would need to use an 11:1 high compression piston due to pin placement.

F20B's use 1mm smaller valves to fit the chamber with the smaller bore. however these engines come with dual valve springs on both intake and exhaust valves. for use with the type s cams that come in the manual models of these engines. just because they come with a beefier rod and dual valve springs doesn't mean it can take 10000 rpm all day long. it isn't a b series. this is a common misconception when people run these engines. hence dropping valves. any h series will drop a valve if constantly revved past 8500.

this is true for any engine--- the larger the displacement the lower you can rev it safely. a b16 will handle 11,000 all damn day, but it is a 1.6L an h22 being a 2.2L will only handle 8500 safely, any higher they don't make power and valves start to float. why do you think formula 1 V10's are only 1.2-1.5 liters. they can safely and efficiently rev to 18,000 rpm, break that down and that's one piston moving from tdc-bdc 346 times a second.

wantboost

iTrader: (2)

Yea I figured since the f20b has a closed deck iron block I could just bore it out to 86mm to run k pistons, it's the easiest solution to forge an f series and a lot of people run that block at 86mm with no issues. the iron block is also what's swinging me towards the f20b as opposed to the vtec h23a... frm sleeves are the devil lol. however given the f20b has a different rod length and thickness than other f/h series motors I rel that any forged connecting rod would be a custom piece. not that big of a deal IMO since my extensive searching hasn't yielded a viable "shelf" forged rod as of yet. plus the fact that the f20b uses what is basically a small valve h22 head it means I have a good number of options for cams and valvetrain. I am debating (if I go f20b) if I should remove the iabs in the intake manifold and port it a bit or run a k rbc mani or some aftermarket h manifold. I mean I think I could integrate the butterflies into the tune, especially since I could make a lot of torque with them.

although the oem pistons and rods are fairly strong, especially compared to b series parts which people are making 300-350whp on with no issues... so I think at first I could make 300 on a stock f20b with a good tune on 93 and methanol injection.

Shadowcat

all F20b's are open deck. which means, for boost it would be a good idea to have a good machine shop weld in a block guard or look into cnc werks. F20b's are also 11.1:1 compression, so boost on stock pistons would require 93, c16, e85, or meth to deal with detonation. only jdm 92-95 H22A's have closed deck blocks. all other h/f series are open

like I said, I am using a 55mm main bearing h22a4 crankshaft. which is a direct drop in to the f20b block. thus I can use off the shelf eagle rods for the h22a4 crank. as well as all h22a4 bearings. only custom pistons would have to be made with the 85mm bore, as discussed before.

I am going to be using a k2h adapter and use an rbc manifold on my f20b.

it took me a long time to figure all this information out due to the fact there is only a few people that forge f20b's my main selling point with going with this particular engine is the iron cylinder walls.

wantboost

iTrader: (2)

Yea I forgot bisimoto has forged pistons and rods for the f20b. the other nice thing is that the f20b has forced pin oiling which helps control friction and cooling in the top end of the motor.

I know a few people making 300-350hp on stock f20b motors with just ARP headstuds, although they aren't really needed because the f20b already has fairly beefy head bolts.

when I can get around to swapping the accord I am going to delete the balance shafts and get som sort of cam, maybe bisi's 2.4 along with (obviously) springs and retainers. given the motor is a true manual I can make some money back by selling the springs and cams. I'm also going to lightly clean up the ports, deshroud the valves and polish the chambers, along with arps and a new OEM gasket. should make for one hell of a street car since I plan on using my evo9 twin scroll 16g, maybe upgrading to a billet 20g wheel and slightly larger turbine wheel.

the intake manifold is still up in the air

typerturbo29

iTrader: (1)

Looks like I might be going with a Mark III Reaper instead

wantboost

iTrader: (2)

You really need to read and post in the Holset thread. your answers are in there.