What to do next? Heads or Exhaust

[macca_779]

Just throwing out the question on what would be the best choice of mods to do next. Heads or Exhaust.

My Exhaust is currently the stock HSV system incorporating bla bla bla:
# HSV stainless steel exhaust extractors.
# HSV high capacity, low back pressure 1.8 litre catalytic converters.
# HSV big bore 57mm dual exhaust system.

Bear in mind the stock HSV system is alot better than the equivalent Holden, so its not like I'm totally strangling the engine although I am aware it is still a restriction. I am undecided on what would be the best to get. I want power not noise. As long as it still sounds good I could care less about note as long as I'm making the most amount of power out of the system I choose. So far I'm thinking 1 3/4 4-1's high flow cats and twin 2.5inch F1 system. Twin 3's are an option but only if they make more power.. Same goes for 1 7/8 headers.

That brings me to my next option. Heads. While my exhaust is a restriction, so are my stock 853 Heads. Especially considering I am cammed.

Either of the two mods will bring a decent lift in power. Doing both would obviously compliment each other, but I'm not in a position to do that yet.

I'm happy with my exhaust note the way it is now. So that is not a factor in my decision at all.

Bang for Buck, I think Heads will net the bigger gain. Especially in low to mid torque areas which is where the car operates 90% of the time.

Cost. I would be going for Higgins CNC Heads. So the price is going to be under 2k. An exhaust would probably be quite a bit over 2k if you throw headers into the equation as well.

My delima is I know I would rather do heads.. But what will net the best bang for buck?

[STATIE]

Ask your tuner - he should be able to point you in the right direction.
























:hide::lol:

[macca_779]

Ask your tuner - he should be able to point you in the right direction.
:hide::lol:

:rofl: Very funny Statie.

Seriously though. I think Heads will net more kw per $. I just want to see if the majority agree or not.

[macca33]

I voted for heads, simply because they provide much better manners and torque for a street car such as yours Ryan.

If you are limited at this point in time by funds, then doing heads will still allow you to purchase a cat-back (or extractors, or cats) later on, without having to spend on a full system at the one time.

The advantage of exhausts is that you can do them piecemeal - whilst you cannot do so with heads.

cheers

[NefariousLS1]

:rofl: Very funny Statie.

Seriously though. I think Heads will net more kw per $. I just want to see if the majority agree or not.

kw/$ is not as important as the increased drivability that u know u will get while keeping it somewhat stealth

[macca_779]

Well I'm actually pretty surprised by the results thus far. At least the majority can see where I'm coming from and agree with my reasoning. I honestly expected everyone to say exhaust as most people do that as a first mod.

Not this kid though. LOL. I must be the only guy around here running around cammed with a 100% stock exhaust. The way this is going Heads will be added to that too.

Funny thing is. Cam and Heads for me is still cheaper than a full exhaust.


I voted for heads, simply because they provide much better manners and torque for a street car such as yours Ryan.

If you are limited at this point in time by funds, then doing heads will still allow you to purchase a cat-back (or extractors, or cats) later on, without having to spend on a full system at the one time.

The advantage of exhausts is that you can do them piecemeal - whilst you cannot do so with heads.

cheers

Funds aren't the issue. Justification to mod the car to the misses is. One thing at a time I can get away with.

I see where your coming from with the exhaust being able to be done piece by piece. I'd rather just get it all done at once though and buy the system complete as I will no doubt be installing it myself.. Like everything else I've done to the car.

[Blown 540]

Funds aren't the issue. Justification to mod the car to the misses is. One thing at a time I can get away with.

I think a lot of us can relate to this Macca.:)

Higgins heads will work every time,the guy knows his stuff.

[macca33]

I think a lot of us can relate to this Macca.:)

Higgins heads will work every time,the guy knows his stuff.
Yep! :yup: on both points!

[Dillzio]

Since you already have a half decent exhaust system, i've voted heads.

[gavlotic]

i voted exhaust - i recon stock hsv sound too quiet for my liking.

[Dillzio]

Sound, phhhttt, as if anyone pays 2G to make their car sound better? Improving performance and economy are where it's at! :headbang:

If you are doing your heads, you may as well bang on a LS6 inlet manifold with a biggger throttle body too.

...And while you're at it, lets not forget NOS, rocket boosters, a parachute to finally slow down, and an ejector seat incase the parachute doesn't work.

A racing stripe is another sure fire way to increase your 1/4 mile time, in fact it apparantly makes the car go almost as fast as painting it red.
:rofl:

[KPWISHN]

Sound, phhhttt, as if anyone pays 2G to make their car sound better? Improving performance and economy are where it's at! :headbang:

Pffft, the sound a car makes is one of the main things I am concerned with and at 2 grand is a very cheap upgrade. Performance comes first though and I reckon you should do both at once if money isn't an issue Macca. Tell the Mrs it is only one mod. :) If you really are only doing one though, I would do the full exhaust.

[Rub]

i vote heads... because heads came up when i flipped a coin...

[debencha]

spotted theese on ebay can anyone vouch for them?

http://cgi.ebay.com.au/CNC-Ported-Factory-LS1-Cylinder-Heads_W0QQitemZ280333673853QQcmdZViewItemQQptZAU_C ar_Parts_Accessories?hash=item280333673853&_trksid=p4634.c0.m14.l1262

looks like they have stock springs.so that would be added cost unless you have some

[macca_779]

Sound, phhhttt, as if anyone pays 2G to make their car sound better? Improving performance and economy are where it's at! :headbang:

If you are doing your heads, you may as well bang on a LS6 inlet manifold with a biggger throttle body too.

...And while you're at it, lets not forget NOS, rocket boosters, a parachute to finally slow down, and an ejector seat incase the parachute doesn't work.

A racing stripe is another sure fire way to increase your 1/4 mile time, in fact it apparantly makes the car go almost as fast as painting it red.
:rofl:

I already have an LS6 manifold. Throttle body would be nice.. But damm its hard to justify one when they cost so bloody much and do so bloody little.

[ova400]

The extractors connect to the heads and as such all need to be replaced at the one time - thats what I would be sticking to, try and do it all.

I would go the heads over the exhaust though if only one can be done.

[duke5700]

Heads for sure... Your cam isn't that big that it will be totally strangled by the pipes. Heads will fill bottom and mid range.

I would port the LS6 manifold while you where doing it.

T/B is a waste unless it was a Fast90/90 combo. Even still on a big cammed/higgins head(it was banana bender spec) car here in Canberra the Fast90/90 only picked up about 15-17rwkw right at the top. The limiter was also lifted from 6800rpm to 7500rpm. The midrange was not that much better to justify it.

You can always pick up exhaust bits as you go... cat back here, a set of cats there and extractor or two here.

[HSV271]

My vote is for heads as well. ;)

It really depends what you are after from your ride and how much $$$ you are willing to pour into it. As others have said there is plenty of great info on here to pour through that will give you an idea of what can be achived.

Mine went from 201rwkw to 255.9rwkw with just a cam/tune/otr/exhaust(tri y's-2.5', std cats). With a less restrictive exhaust, better cats, different OTR I could have seen 260-270rwkw maybe... but if I did the heads as well I would have seen closer to 300rwkw or even just over.

Try an find a good LSx tuner in your area that can advise you as well as the knowledge on here.

Good luck... (Go the VX's...): :goodjob:

[macca_779]

Thanks for all the comments guys. I was pretty confident that heads was the smarter decision to make. I just wanted to see that justified by the general consensus. Which it most certainly has been.

As can be seen here off the higgins website. For my cam lift of .581 the gains are massive.

http://www.higginsracedevelopments.com/images/cnc_graph_ls1.jpg

I'm pretty confident that ported heads would net greater power everywhere with obviously a lot more gain down low than an exhaust would.

I'm curious to know why the guys that choose exhaust did so though?

[Dillzio]

I think the guys that chose the exhaust are just a bunch of show ponies! They're more interested in how cool the car looks and sounds, than how well it goes.

I spoke to my tuner from Enhanced Automotive about upgrading my throttle body, and he said it's not worth it unless you also go the LS6 manifold. This strongly suggests to me that if you do have a LS6 manifold, a bigger throttle body will yield an improvement. As mentioned above, porting the LS6 manifold sounds like a good idea too.

Oh, and did you consider the racing stripe?

[KPWISHN]

I'm one of those show ponies you are on about dillzio. If all your worried about is max performance get $2000 worth of NOS setup. I suggested full exhaust not only because they sound great (decent ones anway) but because they serve a purpose. Macca knows what both will do to his car and is merely posting for different opinions.

dillzio, have you ever even had a set of aftermarket heads? :)

[SS Enforcer]

Try an find a good LSx tuner in your area that can advise you as well as the knowledge on here.

Good luck... (Go the VX's...): :goodjob:

Good advice for the OP there have you any sugestions.:)

cheers



I spoke to my tuner from Enhanced Automotive about upgrading my throttle body, and he said it's not worth it unless you also go the LS6 manifold. This strongly suggests to me that if you do have a LS6 manifold, a bigger throttle body will yield an improvement. As mentioned above, porting the LS6 manifold sounds like a good idea too.



I think you will find all ls1's after the VT had the LS6 manifold on them standard . Maccas Senator would definately have one.


OOps just saw it's a VT senator so maybe it hasn't an ls6 .......

cheers

[BlownLS7]

mate i would get the heads quickly followed by a full system, i feel they go hand in hand, and i feel if you get full system you will benefit by saving as you must be able to o a better deal on full system,

and o Dill , yes im a tosser , i have a system

i wanted it to look goo as well

cheers Paul

[Dillzio]

Come on guys, can't you take a joke?

I have quite an awesome twin exhaust system myself- 3" difilippo headers with 1&3/4 primaries, going down to 2&1/2 inch after the difilippo cats, through a cross-over piece, then going into straight-through mufflers, and a straight-through resonator.

I certainly wasn't claiming that you had to be a show-pony to get a sports exhaust. I was just saying that since Macca already has a reasonably good exhaust system, upgrading it would cause a minimal increase in performance, so you'd have to be a bit of a show-off to invest 2G or so in an exhaust just to make the car sound better.

Oh, and in answer to your question KPWISHN, yes, i have had after market headers before. I'm not sure what this has to do with this thread, but on my old VH that got stolen I had the heads ported and done up for LPG and a stage 4 cam. :-p

[vyc4b]

I opted for the full system first Ryan, as I believe you should, but it is hard to outlay some much coin for seemingly stuff all performance,
to me it just sounds like the 'right/normal' order to do it......I am a BIG wrap for after market Heads though as you know.
Good luck mate..............in finding a Tuner.
:fishing:
Cheers.

[hally]

I voted for the exhaust myself, I've never had a cammed or headed car so in a lot of respects my opinion may not be as valid as others who have had that experience.

But my reasoning was based on the two factors. Firstly I get a dirty great smile every time I kick my ute over in the morning and every time I get on the gas. To me one of the most enjoyable aspects of owning a V8 is that joyous note you'll achieve with a decent exhaust.

Secondly I figured between your 220 cam and a decent set of heads I would've thought the stock HSV exhaust would be well and truly out of it's depths and would prove to be quite a restriction. There's guys who reckon they've seen 300rwkw with that cam and heads so I can't really see the stock system being even close to sufficient for the task.
So my reasoning tells me why lash the money on the heads when as of now you could not enjoy the full benefit of having them on the car. My 2 cents anyway:)

[macca_779]

I voted for the exhaust myself, I've never had a cammed or headed car so in a lot of respects my opinion may not be as valid as others who have had that experience.

But my reasoning was based on the two factors. Firstly I get a dirty great smile every time I kick my ute over in the morning and every time I get on the gas. To me one of the most enjoyable aspects of owning a V8 is that joyous note you'll achieve with a decent exhaust.

Secondly I figured between your 220 cam and a decent set of heads I would've thought the stock HSV exhaust would be well and truly out of it's depths and would prove to be quite a restriction. There's guys who reckon they've seen 300rwkw with that cam and heads so I can't really see the stock system being even close to sufficient for the task.
So my reasoning tells me why lash the money on the heads when as of now you could not enjoy the full benefit of having them on the car. My 2 cents anyway:)

Thanks for your thoughts. But I think you would be surprised how well the HSV system can flow. There aint some magical brick wall that it will hit I don't reckon in an N/A state with my cam. 23% more CFM of Intake Air via the CNC heads will no doubt give it quite a tickle. That should at least give me another 10kw (being conservative here) at peak but obviously alot more down low where the exhaust isn't a restriction. So even 10kw will give me approx 270rwkw.. That aint bad really and is comparable to guys with full exhausts and a similar cam to mine..

Like I've already mentioned. Exhaust note is not a selling point for me. The car already sounds good to me with the stock system and rear res removed. Its not over the top, sounds good, and due to my cam being conservative also, I never get harassed by the 5 0.


I opted for the full system first Ryan, as I believe you should, but it is hard to outlay some much coin for seemingly stuff all performance,
to me it just sounds like the 'right/normal' order to do it......I am a BIG wrap for after market Heads though as you know.
Good luck mate..............in finding a Tuner.
:fishing:
Cheers.

Thats why I expected more people to choose exhaust.. It is the normal progression for most people and thats fair enough. Thing is an exhaust will give me a gain everywhere but mostly up top. Heads will also give me a gain everywhere but mostly through the guts (on my current exhaust).. I will go Heads none the less. What really interests me is my torque delivery is already really flat and fat. With Heads its going to be even flatter. I'm pondering almost turbo like yet a few hundred newtons short.


Good advice for the OP there have you any sugestions.:)

cheers



I think you will find all ls1's after the VT had the LS6 manifold on them standard . Maccas Senator would definately have one.


OOps just saw it's a VT senator so maybe it hasn't an ls6 .......

cheers

I fitted an LS6 the week after I did my cam... Looong time ago.


Good advice for the OP there have you any sugestions.:)


Yeah I'd like to hear some suggestions.. My current tuner managed to squeeze out a fair bit more than your tuner did after the original full custom tune to my car. Problem is my tuner doesn't have his head in the industry everyday to have lots of data on my desired combo. He's stuck working on big grey flying things with real engines for a day job.

So I ask the people that actually buy gear for their cars and not just sell it. Its worked for me so far.

[NZSHAKER]

I reckon Heads as its what im looking into now to try and smooth out my cam a bit....just what sort of heads is the problem im having, with the oz dollar still not that great but these have my eye Here (https://www.patriot-performance.com/xcart/product.php?productid=38&cat=36&page=1) not sure why I just like them :)

my cam in 232/234 @ 112 .595 and .598

but then again I have no idea what Im doing

[MickmeMate]

If it was me i personally would go exhausts depending on budget

[macca_779]

If it was me i personally would go exhausts depending on budget

All well and good and I would agree if I didn't have a cam. My cam with its rather aggressive lift will respond very well to heads.

[boyley]

I had a stock exhaust for a couple of months after I fitted the cam Macca. Once I fitted a full system it netted 0.3 secs at the track so its a gain but maybe less than one would expect. So the fact you've got a budget and you want the best bang for buck then the heads would be the go. Then later on as macca33 says you can add the exhaust system bit by bit. I reckon a simple set of racing cats would net you a gain at only a couple fo hundred bucks.

[ebbett21]

Wouldnt bother with the heads. Once u do the heads then it leads to the power bug costing heaps like opening a can of worms.

[NZSHAKER]

Wouldnt bother with the heads. Once u do the heads then it leads to the power bug costing heaps like opening a can of worms.


I reckon the can of worms was open with the cam :)