Jump to content
SAU Community

Recommended Posts

  • Replies 112
  • Created
  • Last Reply

Top Posters In This Topic

if you were to bolt that manifold onto a car and the car not being able to control boost.

then yes it is defective in design.

i dont see the point in having a manifold that cant control boost....what good is it?

EDIT::

okay i just realised that manifold has twin exit points. if even after having 2 wastegates and still being unable to control boost, id pity the fool who bought one.

Edited by Jap_Muscle

Eitherway, there doesnt seem to be any manifolds with a merge collector design that have wastegate placement spot on and work perfectly in aus at a reasonable price.

If there was one, im sure they would be making an absolute killing over the other couple of manifold makers who have been making them from the get go.

Anyway, abit slow, but this is what I did on our race car setup.

post-12828-1255898041_thumb.jpg

So Jap_Muscle....whats the answer to the problem?

the answer is to increase the diameter of the pipe that leads to the wastegate.

im not 100% sure but just thinking about what you guys have done (wastegate on the housing) your affecting the airflow in the housing which had millions of dollars spent on it for the design of airflow.

i had the exact same problem on a previous setup. we removed the exhaust and had the manifold venting to atmo to confirm it was indeed the exhaust that was the problem. And it was still making 23psi which is crazy.

we took off the manifold off and increased the pipe to the WG to 60mm and attached a 60mm gate.

problem solved.

Michael, you can call any manifold maker and ask them specifically to make the pipe to the WG larger. theres nothing hard about it.

Edited by Jap_Muscle

I havent needed to go to a 60mm wg, since my 48mm progate has worked fine how it is now. We had boost control issues whilst on the manifold, even with an increase in wastegate pipe size which kyle did to help fix this issue, but it didnt work, but that was a couple of years ago now. Since then I put the wastegate on the housing as pictured and we now have perfect boost control.

Everyone seems to think it might affect flow....it very well may, but in terms of power and response, it made absolutely no difference to power, response on the dyno or at the track. There appears to be absolutely no downside to this mod atleast from what ive noticed over the last couple of years of running it.

But if your larger outlet idea works well for you then thats great...saves modifying the housing. However if everyone who runs a merge collector manifold and has to run atleast a 60mm wg just to get proper boost control...that could be quite costly. Especially since you dont really need such a large wastegate to control boost(in terms of gas flow).

Edited by r33_racer
So are you also saying that the Full Race manifolds are of 'poor design' aswell?

rb%20t4%20div2.jpg

TOTALLY different, the twin scroll manifolds have a gate for only 3 cylinders each so they can get away with it. the Full Race item has twice the gate flow as a single the popular xyz branded manifold.

Unfortunately i don't have any pics of the modded manifolds but it is a fair amount of work to make them hold boost (the easiest was to enlarge the hole and run an oval gate take off point) .

Edited by URAS
if you were to bolt that manifold onto a car and the car not being able to control boost.

then yes it is defective in design.

i dont see the point in having a manifold that cant control boost....what good is it?

EDIT::

okay i just realised that manifold has twin exit points. if even after having 2 wastegates and still being unable to control boost, id pity the fool who bought one.

I still don't see how you say someone is a fool for buying a manifold that 99% of people recommend. Are you calling yourself a fool given you had the same problems??

which is poor design

aint you also running his manifolds?

it actually means the manifold is working too well. thats why etm and 6boost recommend mounting it iff the housing. the purple rh9 r34 does this, aswell as lots of other big setups.

I still don't see how you say someone is a fool for buying a manifold that 99% of people recommend. Are you calling yourself a fool given you had the same problems??

you misunderstood.

what i was saying was if that manifold had all 6 cylynders venting to 2 WGs and still not being able to control boost, i dont see it as a very well designed manifold.

but someone pointed out that its 3cyl per WG....which should have no problem wat so ever.

i have purchased a 6boost manifold on my earlier setup, apon realizing the problems it had with my setup, on my second request i asked that certain things be changed, and i dont have a problem now.

thats all im saying.

but i think we are going slightly off topic here, if you guys would liek to talk about what makes a good manifold feel free to create a new thread.

On the last page i posted a picture of the Heat Treatments Racing Gtr. For those that dont know, this is the car that holds the GTR world record. It has the wastegate mouted off the exhaust housing due to better boost control. If the fastest rb26 in the world has issues with controlling boost (or its so much better from the housing), id say its probably not solely a manifold issue.

On the last page i posted a picture of the Heat Treatments Racing Gtr. For those that dont know, this is the car that holds the GTR world record. It has the wastegate mouted off the exhaust housing due to better boost control. If the fastest rb26 in the world has issues with controlling boost (or its so much better from the housing), id say its probably not solely a manifold issue.

True, but if room wasn't an issue a properly built manifold wont have an issue, the housing is a quick easy job whereas making a manifold with enough room between collector and turbo flange to accept the correct size and angled (proper angle should follow exhaust flow not be a right angle) wastegate exit pipe is a far harder job. all the Decent jap ones ive seen (at signal) with T88's and T51's tend to have either two feeds into the one gate pipe or a large exit pipe that comes out nearly vertical and then does a 180 back down to the gate.

This is a dodgy paint version of one of the fixes, this pic does not show the correct exit radius (looks like a 90 but its more like 60 when done correct) but it gives the general idea. In the origin pic you can see the gas need to pull more than a 90 degree turn to exit the gate pipe, we oval the hole and take a large radius 90 (bigger diameter) and angle cut the manifold end and merge it (final gate position depends on the setup) that way we increase the volume but reduce the exit angle (reduce it by half) from the merge. On one setup for a mate we actually ran double gate exit points merged to a single gate but it was ALOT of work and not feasible to do as a charge out job.

post-34927-1255946272_thumb.jpg

post-34927-1255946336_thumb.jpg

Edited by URAS

pretty good for a paint drawing trent...it explains what you mean well enough.

My idea was similiar to yours except to protrude the top section of the pipe into the collector 5-10mm to actually disrupt the exhaust flow and force it into the outlet. Even with that i dont think you would notice any difference in lag/spool from the upset flow.

its a bit hard to apply the same concept of 1000+hp cars with ours.

the reason those cars have WGs off the housing is because of the extreme applications those things run.

so you are willing to dismiss that way of mounting the gate because its on a big dollar big hp drag car yet you think it's 'dodgey' and not the best way to run the gate, i woulda thought the average joe with his street car would opt for the more pocket friendly option and the big dollar race team outfit who spends thousands on r&d and engine development would use the more expensive and best option available. maybe you should get in contact with the guys at heat treatments and let them know theres a better way of running the gate :D

My 6boost manifold has the gate pipe on an angle, I was originally worried that it would be a 90deg exit but was quite happy to see that it was on a healthy angle.

Engine isn't together yet but when it is I'll report back with any boost control issues. Setup is pretty much the same as TiTANs'.

I will mention however, that Kyle (6boost) advised I ditch the 44mm TiAl gate I had to go for the bigger 50mm Progate as his manifolds, on RB engines, had trouble controlling boost under 20psi with smaller than a 50mm gate.

Edited by bubba

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



×
×
  • Create New...