Jump to content
SAU Community

Recommended Posts

im always up for tips on how to reduce lag, and recently saw a dyno graph with a gt55 turbo on a supra which had a curve like it was a t04z.

the supra was stroked to 3.4L and some nice cams but he also mentioned that half the reason why the spool was so insane was because he had a "spool valve"

from wat i understand its basically using a split pulse manifold system and blocking off one side to force the exhaust cases through the other one. resulting in more restriction thus faster PSI buildup.

any professionals care to explain this tatic any any pros and cons?

honestly never heard about it until now

15.jpg

btw does anyone actually sell these in aust?

Edited by VB-
Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/
Share on other sites

I see thread pop up about this every few months on other boards. I've never actaully seen anybody use it other than that one write up with the Supra, but it requires a NON-split pulse/twin scroll manifold to work. It's interesting for sure, but I've got a split pulse manifold, so I'm not going to be a guinea pig. How much do they cost?

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4523705
Share on other sites

im always up for tips on how to reduce lag, and recently saw a dyno graph with a gt55 turbo on a supra which had a curve like it was a t04z.

the supra was stroked to 3.4L and some nice cams but he also mentioned that half the reason why the spool was so insane was because he had a "spool valve"

from wat i understand its basically using a split pulse manifold system and blocking off one side to force the exhaust cases through the other one. resulting in more restriction thus faster PSI buildup.

any professionals care to explain this tatic any any pros and cons?

honestly never heard about it until now

15.jpg

btw does anyone actually sell these in aust?

I don't see how this would be effective at spooling a turbo any faster. Basically this would create more pressure on the manifold side of this valve as the exhaust gasses try and pass trough what is a smaller opening and as i have been taught increased pressure does not increase flow through the same sized hole.

Basically this is choking your exhaust. The best way to spool a turbo is to get as much exhaust gas onto that turbine wheel as soon as possible. Putting a restriction like this in place i can't see how it would work as you are basically halving your exhaust flow with the restriction like that in place...

use this calculator ( http://www.efunda.com/formulae/fluids/calc...iction.cfm#calc ) to see that increasing the pressure without changing the pipe diameter does not alter flow at all. change the pipe diameter however and watch the flow increase.

I wouuld say that there would be a optimal size in exhaust header diameter to keep flow and gas velocity at an optimal level.. but to my mind a contraption like this wouldn't help.

My two cents, hope it helps.

Not to mention companies like HKS/GARRETT etc probably don't make these and that would be a fairly good indication as to whether they work or not.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524082
Share on other sites

It would work by accerlating the gas flow into the turbine at low revs. so instead of having a large area of slow moving gasses they have a smaller area of high speed gasses.

I could work in theroy but without having serveral diffenent cars with it to back up the results its all hersay.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524108
Share on other sites

The fact that they could improve spool etc definitely makes sense - its effectively like hugely tightening up the turbine a/r, though ultimately I don't like them - they would make the breathing of the engine very inconsistant and even when its open I really can't see it doing anything other than creating a restriction. All the dyno plots I have seen with hem being used seem to finish at the point the "normal" setup catches up... what happens to top end flow?

There may be a better way of doing the same kind of thing.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524149
Share on other sites

i agree with lithium, causing a restriction would basicly rack up psi way faster.

as far as top end, i dont know how this would be possible due to restriction. but they claim it gives a 25% INCREASE in top end and improved spool.

if i can get my hands on one id defiantly be interested in trying it out.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524220
Share on other sites

It effectivly halves your a/r then opens up at a certain psi when the turbo is well on it's way to being spooled. It's kind of like a poor man's variable geometry turbo. I'd be worried about it standing up to high temps. I have no doubt it works, but how well and at what cost/pain in the butt are my questions.

And basing whether or not something works off of whether or not HKS or Garrett makes it is rediculous.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524309
Share on other sites

I did once see a diagram of something along those lines but I smell marketing rather than function driving this idea .

Firstly to have it work properly you'd need an open collector manifold with that thing between the manifolds mounting flange and the twin scroll turbine housing .

What it does is feed all the engines exhaust gas through one side of the divided turbine housing until the plates throttle opens up .

I image once the boost , or preferably the exhaust manifold , pressure reaches a set point the actuator opens the throttle valve .

The downside is that the throttled side won't flow as well as the open side and the open collector manifold won't work like a true twin scroll system .

I think a 3.4L 2JZ type thing should not have dramas making torque off boost or kicking a big turbo into life if the manifold/gates and the overall state of tune is on the money .

Gimmick I think , cheers A .

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524621
Share on other sites

oh that and they are 500usd for a t4 flange.. a guy on ebay made some the SAME for $100 but got sued by sound performance coz they have a patent pending on it...

evan though borg warner patented the concept using a valve in the actual turbine housing....lol

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524719
Share on other sites

$500 isn't too bad if it works I guess. Holset does the same kind of thing with variable vanes in the exhaust housing effectively changing the a/r. It makes a 600rwhp turbo spool like a stock turbo, but the problem is it's electronically controlled via the factory Dodge ECU and people have yet to make it work real well in a non-OEM application.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4524842
Share on other sites

It's already been around for a couple years. I think they were having some kind of "development problems" which is why they put the idea out there, but didn't sell it yet. Maybe making it last on high hp daily driven cars is still a big hurdle.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4525225
Share on other sites

Hmm interesting idea, never come across it before. However when its fully open, surely the side with the valve in it would be at a greater restriction than the other side causing a larger pressure build up in the runners for cylinders 4, 5 and 6. This wouldn't have a slight negative effect?

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4525235
Share on other sites

Hmm interesting idea, never come across it before. However when its fully open, surely the side with the valve in it would be at a greater restriction than the other side causing a larger pressure build up in the runners for cylinders 4, 5 and 6. This wouldn't have a slight negative effect?

you would think so huh?

but they claim it would ACTUALLY increase top end by 25%.......dunno how but insane if true.

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4525307
Share on other sites

Obviously you would have to run a normal (non split pulse) manifold, and a split pulse turbine housing ....... when closed all the exhaust gas is re-directed thru one side, generally 1/2 A/R of total housing rating. So spool up would be same as a much smaller housing, and top end of the larger housing. There would be a slight restriction to the runner with the plate in it obviously, and so i would say power could be slightly lower , top end. Depends on how hard the housing is working to make the power you are at.

As i mentioned , this was a factory setup on the S4 Rx-7. It however , used a setup more akin to a wastegate flap, not a butterfly.

I wonder what materials they used, as that flap looks quite thin. You'd think there could be probs with it sticking too with the huge heat range it would be getting.

Gary

Link to comment
https://www.sau.com.au/forums/topic/264645-spool-valves/#findComment-4525393
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • So, version 4 intake is on its way I was looking at these a while ago but at around $200 or more it was a little pricey for something that might not work, but, I had it in my watch list, but, I got a message saying it was on special, and I had a code thingie to use, it eventually came in at $120 delivered, so BAM, BUY NOW.....LOL I'll need to have a look when it arrives but I feel it will "look" better than what I currently have, as it comes with a PCV fitting, so I will be able to get rid of the alloy pipe that goes to the throttle body with the PCV fitting  Well, that's what the voices in my head are telling me  Oh, and this happened today Yeap, it was a Trojan, and it was cheap, so I headed back to the hardware store and actually spent a little bit more on a heavy duty,  one that was actually recommended by a plumber mate, a Cyclone one with a fibreglass handle that is actually rated for clay The broken shovel will eventually be "modified" into a short handle shovel
    • When you pulled it off, there is no signs of blown head gasket? Is it possible you have some other issues going on? Possible cracked blocked? Or do you think it's straight up lifting the head? Did you check what the head was torqued to before pulling it down (To see if possibly they're stretching, or starting to break threads out etc)?
    • Seems like a decent result for a modded JZX110. They are bulky in comparison to the 100 and 90 models (which I'd prefer myself) but they are getting very few and far between here in JP these days. Thanks for the detailed review and the import process into the UK. I also have a car which I'm hoping to export from Japan at some stage so it's good to know if someone from the UK was interested in it. By the way the corrosion underneath is par for the course for cars which were located in/near the mountains or along the Japan sea coastline. They get huge amounts of snow every winter and the sodium chloride is used on the roads. Many cars have some kind of rubber like treatment underneath but they tend to limit it to the wheel arches underbody and fuel tank. Suspension arms and sub-frames will have similar corrosion to your JZX110 which is a common sight. See it all the time and car dealers here generally don't even mention it unless asked.
    • If the sound goes away when you clutch in, the 1.5/2 way diffs are just shit, and you are a normal person. The diff is likely "fine" but driving at anything under 30kmh is a violent horrible experience. It would be exaggerated with solid diff bushings and subframe bushings if you have those.
×
×
  • Create New...