WB 304 horsepower gains?

[NotSoOrig.]

Hi all,

Just after a bit of advice on setting up my 304 WB ute to lay a bit more power to the wheels.
Currently sits around the 220rwhp with fresh rebuild, 10.1 compression & what seems to be a mild C.O.M.E cam & chip,Bluetops, standard inlet manifold. Custom Cold Air Intake/K&N hi flow , t5 commodore manual, 10 bolt lsd running 3.08gears , Its a nice thing to drive and am happy with the conversion just want a bit more grunt.

I have it prepped to go into my performance shop next week to throw in a 286 (still hydraulic) cam , Haltech ECU for tuneability, full custom mandrel bent exhaust(from my current pacemakers) running x-pipe to two mufflers ( Removing the twin cats i have at present) , and im unsure what manifold route to take as i believe the bananas may start to restrict as i near the 300hp mark?

So basically just asking if this route seems good to you guys? and what manifold should i go for? Or any other tips or pointers from the experts around here.

Sorry if this is the wrong area or whatever...my first post..oh and Im glad to finally be a member..

Thanks in advance.

 

[Not_An_Abba_Fan]

Welcome.

The bananas will restrict it somewhat, just depends on the end result you want.

I have recently built a 355 EFI retaining the original bananas, it has a H304 Crane cam, from ~250hp it had as a 304, I would conservatively say it now is pushing 320-330hp. Flows enough for what we want, (it's a skid car), but the next upgrade will be a Harrop single plane and a 1000cfm 4bbl throttle body. It also runs a Haltech, really easy to tune.

Your wallet is the only real restriction. Bang for buck though, stroking is easier than it sounds. I did this one in my shed, I also flowed the oil pump and did an oiling mod to even out the distribution to both lifter galleries. AV8 is a good site for reference, I got a LOT of great info from there.

 

[Demonica]

I'm biased towards torque power manifolds myself. Best thing I can recommend is give Craig at torque power a call, tell him what you currently have and what your plans for the future is and he'll guide you as to what manifold would suit your needs best. He will pretty much talk your ear off if you give him a chance lol. Awesome, awesome bloke

 

[hq-racing]

Intake will make a huge difference...
What 1 to get depends on cam and look preference..

I personally like the torque power/harrop intakes over twin t/b..

Depending on cam, say you get something that revs from 2,500 to 5,500 you'd want to go a low rise dual plane..
I'm in the same boat atm with intake..

My cams from 3,500 to 6,500 so id either want a low rise single plane or hi rise dual plane..

Get some into some research on those, there a slightly cheaper option then twin t/bs and with these you know exactly what your getting...

 

[Cava454]

If it were me....

Just get a dual plane and 4bbl tb.
Leave current cam
Leave Stock computer and get it DYNO TUNED PROPERLY
3.9/4.11 diff gears.

What's ur current exhaust?

 

[NotSoOrig.]

Yeh i have looked at most options and agree that something low rise would suit my application best, as far as looks go i dont mind either way. Probably end up going the TP but then comes the throttle body...what works best here? Spacer, throttle body straight to high flow large air cleaner i presume, so long as it will fit under bonnet anyways ?

Also another issue ive been having is : In say high traffic situations at lower Rev range the car sometimes wants to surge alot which feels like it would be between diff & trans but everything here is new & tight as...im a bit stumped, i know my rear leafs are lacking bushings which is causing some of the noise i hear when surging but couldnt be the root cause, its also an intermittent problem as it doesnt always happen but often moreso during the cold....any ideas??

 

[Demonica]

I've got an edelbrock 3878 4bbl throttle body with my tp dual plane low rise manifold then a 14x3 inch air filter which only just fits under the bonnet. No way I would of been able to get a spacer in as well unless maybe I went with only a 2 inch air filter.

 

[Cava454]

This engine doesn't need a spacer....

 

[NotSoOrig.]

Cava...

Current exhaust is Pacemaker extractors, twin cats into split 2 1/2" into single muffler back to twin pipes to rear.
sounds and goes ok, just think it couls possibly flow a bit better?

 

[Cava454]

Just change the single muffler section to twin. So it's a true 2.5. No need to spend the cash for a full custom.