Best flow: Tubular or Cast manifold?

[esoung]

As the title says, does a tubular help the flow over a cast manifold? I'm decide upon a T3 ERL or Turbonetics over a tubular. Is it really worth the $300+ for a tubular?

 

[JusMX141]

I've never liked tubular because I've never found a brand that didn't have durability issues. The general consensus believes cast = street car, and tubular = race car.

Take caution when choosing the Turbonetics manifold....a buddy of mine tried to run one with a .82 a/r turbine housing on a GT35R and the turbine housing hit the block. The manifold didn't have a steep enough angle at the end to allow the housing to clear the block, so he had to buy a used SFP Tubular manifold to get his car up and running. The other choice was to install longer manifold studs and a spacer between the Turbonetics manifold and the head.

 

[need2boostpsi]

also cast retains heat which is good for turbo spool!!!

 

[1gDSM4g63]

It's nearly impossible to crack a cast manifold.

As for the T3 housing, the .70 a/r will a Turbonetics will fit.

But does the tubular really have better performance? I've FP say that their cast manifold performs as well as the most tubular.

 

[andy4g63]

Cast all the way for street car. As jusmx said, with tubular there allways will be some reliability issues. Buschur once said: cast spools faster, tubulars have better top end...

Go with ERL...

 

[92tsiawdguy]

i have a cast tubular stainless t3 manifold. No problems and it has a lifetime warranty.

Punishment Racing t3/t4 turbo manifold for Talon/Eclipse

 

[92tsiawdguy]

not cast i ment forged sorry!!!

 

[JeffGST]

Cast all the way for street car. As jusmx said, with tubular there allways will be some reliability issues. Buschur once said: cast spools faster, tubulars have better top end...

Go with ERL...

Did Buschur really say that?

But does the tubular really have better performance?

Yes and No

A cast manifold and an EQUAL LENGTH tubular manifold in theory should be able to achieve the same peak HP, with all other things being equal.

BUT, cast manifold and an EQUAL LENGTH tubular manifold DO NOT have the same HP curve. An equal length tubular manifold (ELTM) will shine in the spool up range, where the cast manifold will fall behind.

Reason...

- A cast manifold has uneven runners that will cause exhaust pulses to enter the turbo in a non-rhythmic pattern. Since the #2,#3 runners are a straight shot into the turbo, those exhaust pulses will reach the turbo sooner than the #1,#4 longer runners do.

- Firing order of the 4G63 is 4-1-2-3. You get exhaust pulses that looks like this

cyl#4 = Long exhaust pulse
cyl#1 = Long exhaust pulse
cyl#2 = Short
cyl#3 = Short

- So when you look at the rhythm above, it will be a

PULSE - wait - PULSE - PULSE - short wait - PULSE - long wait - PULSE (Cyl#4repeat)

On the other hand, an ELTM rhythm would look like this...

PULSE - wait - PULSE - wait - PULSE - wait - PULSE - wait - (Repeat)

Which manifold do you think will spool up faster and smoother?

But once the turbo is fully spooled both manifold should perform the same and achieve very similar peak HP levels, as long as the runners are not a restriction itself.

 

[JusMX141]

Some cast manifolds aren't that great. It depends on the metals that are used in the manifold, the forging process, and how well those metals deal with contraction/expansion through the extreme temperatures that our engines dish out over time.

Here's what happened to an early SBR cast manifold that my buddy had on his car a few years back:

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It had about 4k on it if I recall, and broke at the track. Luckily he trailered his car that night. SBR replaced this manifold under warranty, no questions asked.

 

[turboglenn]

I've got the turbonetics Cast Iron T3 manifold with well over 80K miles on it now f very hard daily driving and track weekends. It has NEVER given me an issue. i've known 2 other people with this same manifold, and only one developed a very small crack (that didn't even leak once warm) right in the top middle of the collector area. I brazed it with an oxy torch and some bronze wire and it's still on the road today 8 years later and 2 owners have called it "new" to their cars and the guy that has it now is still hauling ass on it and not had one issue with any more cracks or the rbaze job.

Now, i know a LOT of SCCA racers and a few street guys that have had tubular SS header/manifolds and about all but 3 of them have cracked and warped in places at least once. I've seen flanges need re-faced and a lot of runner to flange beads break as well.

YOu can keep repairing them, and the weight would be a good saving on a track only car, but id go with a good name brand quality cast unit for the street and DD use.

 

[VETTE_50_TH]

Those ERL's look sik! And they are like 500 bucks, which is about 250-300 dollars cheaper than a regular tubular manifold. I might just be getting an ERL now.

James

 

[JusMX141]

ERL would be my manifold of choice if I was going with a T3 housing on my HX40. I'm not completely ruling it out.

Glenn- what's in store for your car now that the ol' 57 trim went down? Did you end up rebuilding it?

 

[VETTE_50_TH]

ERL would be my manifold of choice if I was going with a T3 housing on my HX40. I'm not completely ruling it out.

Glenn- what's in store for your car now that the ol' 57 trim went down? Did you end up rebuilding it?

Do it!!! T3 with a ERL manifold FTW. Im plan on a HX40 at my house by the start of next semester.

James

 

[97EclipseGSX]

- So when you look at the rhythm above, it will be a

PULSE - wait - PULSE - PULSE - short wait - PULSE - long wait - PULSE (Cyl#4repeat)

On the other hand, an ELTM rhythm would look like this...

PULSE - wait - PULSE - wait - PULSE - wait - PULSE - wait - (Repeat)

Which manifold do you think will spool up faster and smoother?

The equal length definately does.

I just switched from a SFP short route that I had on the car for a few years to a DNP equal length. The turbo seemed so much more responsive while driving the car around town. Logs have shown a 2-300 rpm difference in spool with my T4 PT61. The logs also show more boost at most rpm ranges prior to spool up.

I'm glad the SFP broke or I probably never would have changed it. The welds that held the wastegate tube on broke causing the wastegate to fall off. I guess the dump tube was to heavy?

The only complaints I have as far as the DNP is concerned are that it sits to far off the head and the bolts can only go in from the bottom. So, I had to take my fluidyne out to put it on and you have to take the turbo out with the manifold connected.

 

[turboglenn]

ERL would be my manifold of choice if I was going with a T3 housing on my HX40. I'm not completely ruling it out.

Glenn- what's in store for your car now that the ol' 57 trim went down? Did you end up rebuilding it?

Well, after i get my 9:1 wiseco/eagle H-beam motor back from the machine shop i'll be buying a turbo from a member here. PUtting an HX35 with a BEP T3 flanged .55 A/R housing hot side.

SHould spool nicely..the 57 trim will be sent of to be turned into something else..maybe a 60-1 or something (don't know for sure yet) Or i may put a new wheel in it, balace and sell it, it's honestly in great shape everywhere besides the inducer blades.

 

[soldave]

Probably cast are better but I've had the Punishment Racing budget tubular manifold (the one a bunch of people said wouldn't last at all) on for a year now and haven't had a single problem with it.

(Saying that, it will probably crack on me tonight!).

 

[kidderkennels]

Stay awasy From SBR cast...they are junk...FP cast is Good...and so0o is Turbonetics...When it comes to Tubular...They flow better than cast....But they are pretty expensive....Id stay away From DNP....take a look at SLS, Shearer, ERL, and punishment....oh yea....and JH RACING

 

[JusMX141]

The newest-issue of SBR manifolds are fine. My buddy actually has one of the early new-issue stainless SBR manifolds with "BEP" cast into it on one of the runners....possibly made by Bullseye?

 

[blackGSX2g]

+1 on cast manifolds cracking. I'm currently on an SBR manifold that was ported and drilled for a 38mm WG that cracked after MAYBE 2k miles...if that. No where near as bad as the picture posted above, but still I expected way better than that, especially with the light use I have put on it.

Not sure if SBR fixed their quality problems or not, but for me it's easier to weld tubular metal than cast, so my next mani will most likely be tubular with heat wrap.