4671 cam, 10.5 comp, holden 304, only 170kw sound right?

[delcowizzid]

we run a [email protected] cam on stock piston 304 with only the heads shaved 4 into 1 headers and bananas with 24lbers nearly maxed out .a 70mm TB was pulling 10 kpa of vacuam at full throttle and you can feel the manifold fall on its face pretty early in the revs

 

[Darren_L]

the standard manifold is excellent for low to midrange torque. That's the only thing that suffered a little when I changed to the Trickshift
But as said they fall over at higher rpm. Usually the power curve really starts to flatten out by 5500rpm max, so if your cam is designed to continue making power above 5500rpm, which yours is, then it's going to be seriously restricted by the manifold.
Trickshift continued to make power just over 6000rpm and that was only really limited by my cam profile which is designed to peak at around 6000rpm

 

[mr j-man]

holden definitely didn't have performance in mind when they released that manifold from factory did they....****, even a performer manifold shits on the bananas.
Throw that manifold in the bin lol

 

[383 hatch]

holden definitely didn't have performance in mind when they released that manifold from factory did they....****, even a performer manifold shits on the bananas.
Throw that manifold in the bin lol

Now, come on. The bananas work very well for what they were designed to do, make bulk torque in the low to mid range area. I totally agree in a performance application, they reach their limitation very quickly, but Holden designed a manifold for a purpose and they achieved that purpose. I think you'd find the performer would fall over about the same time the bananas would.

The injected 5 litre, while not a powerhouse by any stretch of the imagination, goes very well for what it is.

 

[Ian Johnston]

I agree with what 383 has said. Daughters 355 stroker with 4757 cam, 10.25 comp, rockets off the line. Yeah, may drop off up top, but seriously, how many people drive in the upper rev range a lot.
And dyno figures dont matter cruising down the street.

 

[Darren_L]

holden definitely didn't have performance in mind when they released that manifold from factory did they....****, even a performer manifold shits on the bananas.
Throw that manifold in the bin lol

they were good for what they were originally designed for.
You probably won't find a better manifold for producing torque in the low to mid rev range. The Grp A manifold made less torque than the bananas and it's torque was across a narrower band.

But yes the bananas seriously underperformed at higher rpm, which is where a performance small block is going to make hp

I reckon Holden should have kept the bananas manifold for the base model V8's and the luxury models, for the people who wanted it for normal street duties, towing etc.
And at least offered the Grp A manifold as an option on performance models like SS, HSV

 

[Deuce]

I reckon Holden should have kept the bananas manifold for the base model V8's and the luxury models, for the people who wanted it for normal street duties, towing etc.
And at least offered the Grp A manifold as an option on performance models like SS, HSV

I think that is a great idea. If only Holden had thought of it 25years ago.

 

[Immortality]

170 rwkw seems to be it with a stock manifold wether it be 355 or 304, tuned a few and thats all they will make.
Throttle body only flows 580cfm so put a decent intake and let it breathe and retune.
70mm tb might gain a few kw but that's it.
Cam is too big and wont let it breathe and comp will also be limited
with the stock manifold.
Intake temps are shocking on them and also hurts power.

I don't think that is strictly true, years ago, I saw a VS HSV Senator with factory 5.7 stroker rebuilt that was putting out about 220rwkw albeit it was built by a local engine builder who was very good at making the Holden engine sing.

No doubt they have their limitations though, heat been a big one.

 

[skyracer]

I don't think that is strictly true, years ago, I saw a VS HSV Senator with factory 5.7 stroker rebuilt that was putting out about 220rwkw albeit it was built by a local engine builder who was very good at making the Holden engine sing.

No doubt they have their limitations though, heat been a big one.

+1

Put the bananas back on my GTS to make the bay look stock and 'clear' a defect for having the vortech. Re-tuned on a second memcal to cruise around while not having forced induction. Still made 210rwkw And that's on slightly lower comp to suit boost. Still felt great on the roads too, but still nothing like an extra 170rwkw that the blower adds. Dyno figures are just numbers. There are tuners that can tune and there are tuners that just have the skill in some sort of black magic on engines.

 

[2INIL8]

I don't think that is strictly true, years ago, I saw a VS HSV Senator with factory 5.7 stroker rebuilt that was putting out about 220rwkw albeit it was built by a local engine builder who was very good at making the Holden engine sing.

No doubt they have their limitations though, heat been a big one.

That's what ive seen on average but by no means the absolute figure
every engine is different too many variables.
Imagine what it would have made with a good manifold!