Performance intake/exhaust options

nfswift · Post by **nfswift** » Tue Oct 16, 2007 2:46 am

So I'm building up a 3.4 PR, and from what I've seen the Trueleo is the only effective small-volume production intake out of the bunch. The rest are un-documentd one-offs, or based off the Fiero intake and are a joke.

Firstly, integrating the SFI/DIS from the 95 engine I'm buying into the intake manifold and block would probably be the best to base a performance build on no?

I know some members here have done one-off intakes, what kind of experiences or results have come out of them so far? My needs here are for a manifold that will efficiently flow the max that the heads (even ported and matched etc.) will be able to support and possibly more CFM beyond that, seeing as I may do mild F/I as the money comes to me.

As I'm not reaaally a F/I buff yet I'm not sure if I'll need to just buy a new manifold when going turbo etc. but hopefully a skilly crafted one-off, or some production manifold that I don't know of yet will be able to fill both N/A and F/I roles??

Successful/practical intake options?

Moving along to exhaust...
Saying I go for a dual-plenum or tubular (IE trueleo style) intake manifold to un-cork the 3.4, I still want my engine to be able to exhale efficiently too, especially if I go mild F/I down the road.

From what I've seen the aftermarket header/manifold selection is pretty slim. My needs here are for a set of manifolds that will flow respectably for a N/A build as well as hopefully get away with supporting a turbo later on if that's possible. Durability would also be a plus here, that may be a matter of metal selection and heat coating/wraps etc. though.

What should I be considering? Are there any production manifolds on the market that can meet my needs or are customs my only real option?

Any real benefits of equal length primaries? What diameter pipe should I be using? What length of runners until they collect?

Any input is awesome, I'm hoping this thread can snowball a bit and be a the source to go to for decent info on the subject...

Pyrthian · Post by **Pyrthian** » Tue Oct 16, 2007 10:18 am

well, I guess a good starting point is:
iron or alum heads? I am assuming iron, since I dont think TrueLeo has made the alum head version of his intake yet.

so, this means starting with much porting. then, the actual intake manifold. there is much porting to be done there also. the injector bungs, the ledge at the end of the ports, the rough casting - especially where the 2 halves come together.

at this point - one guy went ahead, and just put a box on that, and a throttle - and called it done. I am sure this will outbreath the Trueleo, eh? not pretty - but neither is the trueleo.

anyways - it is quite easy to get the intakes to outflow the irons heads. Camaro intake, "enterprise" intake, gutted, trueleo, etc. but - whichever way you go - port the heads. port the intake manifold. at least gasket match.

befarrer · Post by **befarrer** » Tue Oct 16, 2007 2:24 pm

Intake:

Exhaust:

Sorry, I am not much help.

nfswift · Post by **nfswift** » Wed Oct 17, 2007 2:46 am

Basically the deal is my weakest skills are in harness splicing and ECU tuning.

The 3.4 PR allows me to cheaply swap something closer to the stock block and then build on top of that with a higher ceiling on performance (going turbo etc.).

Looking at the aluminum head 60*s there is still very VEEERYYY little performance after market and the swap just becomes more difficult using the 3400/3500 etc.

I'm not looking to make much more than 200hp N/A or 250 turbod, 300 is getting ridiculous for my REAL street needs and reliability can only suffer past that.

Shaun41178(2) · Post by **Shaun41178(2)** » Wed Oct 17, 2007 9:41 pm

Where is the moderation? This thread needs it.

BigRedDeckSpoiler · Post by **BigRedDeckSpoiler** » Wed Oct 17, 2007 10:02 pm

Oh the irony.

nfswift · Post by **nfswift** » Thu Oct 18, 2007 1:35 am

This thread has deviated too much from the topic.

I did not ask what other engines to install.

What I asked, in essence, is how to kill the bog in the 60*V6, I want to beat the piss out of that 4,xxxRPM wall like it owes me money ok?

I do not need to build a race engine, but running 250WHP should allow me to stomp on the occasional V8, shit all over the cocky CAI/Wing/Rims import crowd, and make me proud to be driving an old failing-at-the-seams Pontiac again instead of staring at it sitting in my driveway with exhaust and cooling problems.

Sound reasonable?

nfswift · Post by **nfswift** » Thu Oct 18, 2007 2:43 am

The reason I'm not doing a DOHC is because STOCK IS WHAT YOU GET, replacement parts are scarce and expensive, performance parts are either not to be found or ungodly expensive, there is NOWHERE to go with it as a performance platform without investing WAY more than a built 3.4 (albeit more HP to be had but that is not the point), and reliability is in question compared to a rebuilt and prepped 3.4

I also highly doubt a built 3.4 PR is going to be matched by a stock DOHC in the low end, I'll give the DOHC the top end obviously, but the 60* PRs are virtually ALL TORQUE ALL THE TIME until the 4k wall.

250WHP is more likely a turbo'd goal, 300 crank wouldn't be unreasonable with F/I. 200HP N/A is about what I'm expecting to get, all said and done.

You also need to stop talking about the trueleo products, I never said I was purchasing or endorsing them, I just saw numbers for CFM and figured they did the trick VS the stock 2.8 UIM. I will likely be using a single TB enterprise style manifold.

Aaron I tried to overlook everyones hate for you on this forum due to the fact that you seem to have invested enough time researching and executing your build, but seriously, you need to take it down a notch.

I would hate to see you on track day talking up your 400HP engine (I use this number loosely as 418 is the current benchmark in a turbo DOHC Fiero) that is likely to grenade any number of parts by this stage, only to get stomped by some red-neck who invested half of what you have into a simple SBC that's built well over 500HP.

Just start taking yourself a bit less seriously maybe...

Shaun41178(2) · Post by **Shaun41178(2)** » Thu Oct 18, 2007 6:42 pm

Well if you are sticking with the 3.4 PR I would do this to try to get as close to 200 whp as you can n/a and more later with boost if you are inclined

Hyper replacement pistons.
Moly rings
5 angle valve job with a full port in the bowls and at the ports. Don't just do a gasket match and call the heads ported.
Fully ported lower intake, not just gasket matched
Truleo upper intake with a plate designed for a 62mm tb. They can build this
A crane 272 cam with 1.6 rockers. This will put lift around .500 or so.
The truleo headers, or the Sprint manifolds with a 2.5 inch catback exhaust from WCF or homemade or a open dump.
Underdrive pulley
CRX ebay cold air kit or one from WCF

Cost will be around $3k or so.

The open dump exhaust isn't really that loud untill you get on it. tHen its loud. at idle, its not much louder then stock.

I will probably eventually sell my turbo setup. So that is always an option later on for you too and if you can do 180-190 whp or so with that setup, then with a turbo on 7 psi you should see about 250 whp. Which should get you low 13' timeslips at around 104 mph or so.

The Dark Side of Will · Fri Oct 19, 2007 7:38 am

Did some house cleaning.

Pyrthian · Post by **Pyrthian** » Fri Oct 19, 2007 10:28 am

nfswift wrote:The reason I'm not doing a DOHC is because STOCK IS WHAT YOU GET, replacement parts are scarce and expensive, performance parts are either not to be found or ungodly expensive, there is NOWHERE to go with it as a performance platform without investing WAY more than a built 3.4 (albeit more HP to be had but that is not the point), and reliability is in question compared to a rebuilt and prepped 3.4
......

yes - but - the stock 3.4 DOHC that you get - already kicks the ass of a fully tweaked 3.4 pushrod. everything you buy to bolt onto that pushrod, is an attempt to get the airflow which exists stock on the DOHC. just a simple free port job - and boom, done - you are past what a pushrod will EVER produce. you can turbo both just as easy, you can nitrous both, just as easy. you are gonna pass up 200 hp, so you can take 160hp, and try and try to add 40 hp to it.

I went pushrod cause I am cheap & lazy. I didnt want to mess with the wiring, and already had the block. in the end - it ended being MORE work & MORE money. funny how things turn out....

Mach10 · Post by **Mach10** » Fri Oct 19, 2007 10:36 am

Apologies for getting into the side-track. :salute:

Has anyone ever clearly identified a single cause for the 4k "wall?"

IS it a single cause, or is it a culmination of a host of factors?

Is there a sudden rise in manifold vacuum (drop in pressure) to suggest that the motor is trying to pull more than the intake tract can flow?

Is vacuum relatively constant--suggesting that the heads + cam just can't move the air?

Thought: Has ANYONE ever tried to adapt any part of the DOHC intake system for use on a pushrod motor--specifically the middle and upper? I know the lower is different because the port sizes are monstrously different... But the spacing for the ports(iirc) is similar, and it strikes me that all things being equal, they are pretty damn close in overall size + shape...

'Course, it'd look funny... But seeing as it flows more (and better) than anything out for the PR 3.4... Maybe it's worth a peek?

I've got a full set of 91 DOHC intake peices if someone wants to take some measurements... I just don't have a PR 60Âº to look at.

The Dark Side of Will · Fri Oct 19, 2007 10:38 am

The TDC/DOHC is significantly heavier than the pushrod engines.

The 3500 pushrod engines make the same stock power as the TDC/DOHC engines and are lighter than the iron head pushrod engines. If you get an '04-'05 3500, it will still have fixed cam timing and setting up engine management for it will be relatively easy (though will still require some effort if wiring isn't your strong suit).

If you're dead set on using the iron head platform, then you'll spend some pretty decent money to get power in the low 200's at the crank.

nfswift · Post by **nfswift** » Fri Oct 19, 2007 5:15 pm

Well I picked up a very decent rebuildable core for 180 straight up.

This is my first engine swap and SERIOUS car engine rebuild, it's been all motorcycles up until now. All costs involved I should be into it for 900 to 1000 dollars into the fully rebuilt and tweaked engine. I should be netting at least 190 crank, and compared to stock I AM SURE this will satisfy me until I add some boost. This engine will be my first stab at custom work as well, it'll give me all kinds of opportunities to screw around trying new ways of modifying without being frightened of my investment.

Plus, I'm 19, and if I can get get a speeding ticket in a Toyota Yaris, a 190hp Fiero will get me into FAR FAR more trouble.

I'll just be glad to have a well running rig again, especially if it has more bojangles and that same "little V-8" sound.

The Dark Side of Will · Fri Oct 19, 2007 5:37 pm

What mods are you looking at to get you to 190 at the crank?

If that power level is what you're looking for, then get a 3500. They make 205 stock. With a little bit of looking, you should be able to find one in the $300-500 range on www.car-parts.com

Also, the Gen III engines will respond to boost WAAAYYY better than the Gen I's.

The iron pushrod heads aren't great, but they're not that bad. Falconer, after all was able to get 280 HP from 2.8's and 300 HP from 3.0's. Of course those were FULLY built race engines with throttle per cylinder intakes and long tube headers...

To get power out of an iron head engine, you absolutely have to ditch the stock upper.

If you use the Camaro 3.4 upper, you're a big step ahead of the Fiero upper from the get-go. If you keep the DIS on the Camaro engine, you can even turn this intake around to have the throttle body on the flywheel side of the engine like the FWD setups do.

You'll need a good exhaust setup to get power out of the iron head engines. None of the options on the market now are what I'd call good, although the Sprints or Trueleos are probably the best of what's available.

Beyond starting with the right components, an engine build is about making them work together... Clearances, compression, quench, cam, porting, etc...

Shaun41178(2) · Post by **Shaun41178(2)** » Fri Oct 19, 2007 6:07 pm

I think $1k for yoru build is way underbudget and won't get you anywhere near 190 crank hp.

$1k will get you a a fairly stock rebuild, and will probably do around 160 hp just like stock.

To get 190, you will prob be spending more like $3k

The Dark Side of Will · Fri Oct 19, 2007 6:14 pm

Concur.

BigRedDeckSpoiler · Post by **BigRedDeckSpoiler** » Sat Oct 20, 2007 7:10 am

The Dark Side of Will wrote:Did some house cleaning.

:salute:

BigRedDeckSpoiler · Post by **BigRedDeckSpoiler** » Sat Oct 20, 2007 7:23 am

Shaun41178(2) wrote:Well if you are sticking with the 3.4 PR I would do this to try to get as close to 200 whp as you can n/a and more later with boost if you are inclined

Hyper replacement pistons.
Moly rings
5 angle valve job with a full port in the bowls and at the ports. Don't just do a gasket match and call the heads ported.
Fully ported lower intake, not just gasket matched
Truleo upper intake with a plate designed for a 62mm tb. They can build this
A crane 272 cam with 1.6 rockers. This will put lift around .500 or so.
The truleo headers, or the Sprint manifolds with a 2.5 inch catback exhaust from WCF or homemade or a open dump.
Underdrive pulley
CRX ebay cold air kit or one from WCF

Cost will be around $3k or so.

The open dump exhaust isn't really that loud untill you get on it. tHen its loud. at idle, its not much louder then stock.

This is actually very similar to what I've got.
What I don't have is the 62mm TB (57 instead) and the 1.6 rockers. (1.5 roller tips.)
I'm using FOCOA headers (very similar to the Trueleos, IMO), no cat (until e-check rolls around) and an Ocelot exhaust.
This configuration has a nice thump at idle, but is loud enough to draw unwanted attention if you have your foot in it, however.

You'll also need larger injectors. I'm using 19# Bosch pintle type.

I'm still doing the basic chip tweeking, so the tune is not right.
I'll dyno it, once I get closer.

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Oct 20, 2007 12:35 pm

didn't you already dyno yours at around 130 whp? He won't need larger then 19 lb injectors eihter on a n/a setup.