I have a 87 GT with the original Miller-Woods Stage II turbo kit (8-10 psi). I am interested in updating the heads and intake to improve flow and performance over the stock parts. What are the best heads and intake for a turbo?
There's going to be virtually little options in regards to heads that can put out serious power over stock if you stick with the iron cast heads. If you opt to go with the later aluminum head design you can create a much larger window to be able to put out more power. However, you will lose the ability to run the OEM valve covers. If you don't care about aesthetics and overall OEM looks of the engine then ditch the iron heads.
The intake is going to likely require you to create a custom application. You may look into creating a modification similar to the 'DAWG' V6 intake, which is basically an underside modification of the intake plenum neck right after the throttle body that enlarges it by quite a bit to improve air flow. However even with that you will still be hampered by the plenum to upper intake curvature. Beyond the stock intake design, you could look into a Truelo (I think you would have to get them used, as I cannot recall if the creator is still making them). It would be a pricey route to go, but the intake is complete custom and designed for high air flow.
I do already have a spare stock intake and throttle body that I picked up off the board some time ago with the intent of doing the DAWG mod to the neck and also modding the inside. I saw a thread where some were gutting the inside and welding up the gaps between single and dual ports...think that's what they did? I figured I would port the lower intake as well and port match everything. I also have bored and optimized several throttle body's in the past so planed on that too. I'm not really too concerned about looking stock at this point if the gains are worthy. If I stick with iron heads which are the best as a direct replacement for stock (retain stock look)...I would however port & polish and probably swap out the stock rockers for some 1.6 roller tips as well. I have scene the Truleo intake bu as you said going to be hard to find. I also have heard other intakes mentioned from the 3.1 & 3.4, f-body, etc, but not sure which will work either. Being forced induction and not n/a I don't think I need to worry too much about something like the Truleo to make more power. The car runs pretty good as is but I know some things can be improved with little effort in the heads and intake just to get better flow. I have been searching all over the site but still not sure what fits and what doesn't. I threw out a set of 2.8 S10 heads before i realized they were the same
user La Fiera is offering CNC ported heads for ~$400 - that's dirt cheap. Don't believe anyone who says you can't do anything to the iron heads to make them flow...especially when you have a turbo - what you need is a turbo-specific cam. There are plenty of turbo F-body 3.4's making 350+/400+ ...
You should consider a '7730 ECM swap to take advantage of the knock sensor and DIS on newer v6/60 blocks along with a performance 3.4 rebuild and larger turbo. A T4 is well suited to a 3.4 but even a T3/T4 hybrid can make over 300hp with a 3.4. Your stage 2 is probably putting down about 190rwhp. That small IHI turbo needs to be replaced if you ever go 3.1/3.4.
You're also at the limit of your injectors if those are still stock.
I might have to check out those heads. I'm quite sure the stock iron heads can be improved one reason why I was pissed after throwing the set of S10 heads in the dump. Not really sure how far I want to go with the stock motor in this car (only 46k original miles on car and motor) at this time. The Miller-Woods kit was installed by IRM (Jim Sutter) in MD back in 88, My dad purchased the car from the original owner in 89 and gave it to me about 4 years ago. I do have a spare Garrett T3/T4 from my other car that I have thought about trying in place of the IHI toy. I agree a turbo specific cam would be better but again not really planning on pulling and getting inside the motor right now. I figure I can at least do something to the intake & TB in the car and maybe heads if I get ambitious. My big HP efforts are pretty much fixed on my other Pontiac for now...
Yeah my 89 f-body makes 400+ to the wheels @ 24 psi with stock heads and cam, Precision GT6776e, 60# injectors, LT1 MAF, Translator, TurboTweek chip, Alkycontrol progressive methanol injection, 3" DP, built trans and 3600 converter...3.8L LC2 though
With a turbo you really don't need to port the intake. That is the reason you have boost. But, port matching and smoothing the intake runners will help and porting the exhaust port is a huge issue due to the bulge in the wall which needs to be ground out.
Both did some nice porting work...I have done some in the past on my son's Eagle Talon TSI and also did some light head porting on my TTA heads that was mostly port & gasket matching and some general smoothing/removing castings on the intake side and polishing the exhaust along with port matching and cleaning up the headers as well. I have also optimized and bored out several throttle body's along with porting intakes and exhaust both aluminum and cast iron. Definitely not afraid to do them my self.
How do I post pic's from my PC...do I have to use a external host site ?
The car already has a turbo has since 1988. Turbo car don't care as much about the intake side as they do about getting the air out...but increasing the the flow on the intake will definitely allow more air/boost to be pushed through and less hot air at higher boost levels. Stock valves and cam will be the next limiting factor...I agree port intake, heads and exhaust and it should be a pretty noticeable difference...maybe going to a 1.6:1 rocker will help the stock cam out as well with the newly added air flow.
The car already has a turbo has since 1988. Turbo car don't care as much about the intake side as they do about getting the air out...but increasing the the flow on the intake will definitely allow more air/boost to be pushed through and less hot air at higher boost levels. Stock valves and cam will be the next limiting factor...I agree port intake, heads and exhaust and it should be a pretty noticeable difference...maybe going to a 1.6:1 rocker will help the stock cam out as well with the newly added air flow.
That would be ideal...I wish there were a similar intake to that on my 3.8L TTA (lower and upper/dog house) that would be perfect!
I don't understand the idea that boost replaces a good flowing intake.
Make your intake flow better, and your boost will be more effective (IE: more power production at the same boost pressure)!
Anyway, if you want to max your potential, port the intake and heads, then add the turbo.
Chay
While none of what you say is wrong. If its going to take $100 for parts & gaskets and $400 for cnc heads and several hours of labor to bring it all together, at what point is it more cost effective to just raise the boost 1-2PSI. especially of you already have a turbo that's all.
I went through the top end - ported and prepped the heads, relieved several places in the intake tract, and of course reworked the exhaust manifolds (the turbo conversion replaces the crossover pipe which has another impediment to flow in it that people often ignore, so you don't have to worry about that).
Larger injectors (19 lb and up) and a cut out at 12.5 psi (diminishing returns without an intercooler to go any higher) and mine works just great - for over 20 years.
But I also replaced the pistons with forged, and run a specifically designed turbo cam with less overlap and did a few other things for longevity (strongly recommend a turbo oiler and frequent oil changes or switch to synthetic).
[This message has been edited by BillS (edited 11-20-2013).]
All I can say is I don't agree. Well, ok, I agree to some extent. If you are at your boost limit, you can't raise the boost 1-2 psi without either running out of air, or detonating (the 2 boost limitations). So, if you want to MAX your setup out (and who doesn't?) then just raising the boost is not an option.
Given the same exhaust setup, the intake will still be the limiting factor in your hp production, so why not address it? Too lazy?
I don't agree with getting rid of the plenum. the plenum's job is to create an artificial atmosphere---a short term constant pressure source. Without it you will get massive pulses in pressure...not good. Besides, how are you going to connect the boost to 6 separate pipes and have them flow well???
The Camaro intake will be an upgrade, but as said there is no provision for a distributor.
The '7730 will run DIS with the right code. Also needed is a 7x crank sensor.
Agreed with Scott87GtTurbo, DO pay a lot of attention to the exhaust setup, especially the downpipe post turbo, and general ex turbine size etc. From a mathematical standpoint the turbo system is a variable pressure source pushing through a complex impedance (intake). The exhaust backpressure is subtracted from compressor pressure to find the differential pressure applied to the complex impedance (engine, intake, head, valve/cam system, ex manifold).
All I can say is I don't agree. Well, ok, I agree to some extent. If you are at your boost limit, you can't raise the boost 1-2 psi without either running out of air, or detonating (the 2 boost limitations). So, if you want to MAX your setup out (and who doesn't?) then just raising the boost is not an option.
Given the same exhaust setup, the intake will still be the limiting factor in your hp production, so why not address it? Too lazy?
I don't agree with getting rid of the plenum. the plenum's job is to create an artificial atmosphere---a short term constant pressure source. Without it you will get massive pulses in pressure...not good. Besides, how are you going to connect the boost to 6 separate pipes and have them flow well???
The Camaro intake will be an upgrade, but as said there is no provision for a distributor.
The '7730 will run DIS with the right code. Also needed is a 7x crank sensor.
Agreed with Scott87GtTurbo, DO pay a lot of attention to the exhaust setup, especially the downpipe post turbo, and general ex turbine size etc. From a mathematical standpoint the turbo system is a variable pressure source pushing through a complex impedance (intake). The exhaust backpressure is subtracted from compressor pressure to find the differential pressure applied to the complex impedance (engine, intake, head, valve/cam system, ex manifold).
Chay
Look like the Camaro intake is a better option than the stock intake as far as flow is concerned and appears to eliminate most of the turns and angles in the Fiero intake if it can be made to work easily. I guess the question is will a set of 2.8 P&P heads and a Camaro P&P intake outflow the original Fiero equivalent parts with the same P&P work enough to make the change worth while on a turbo setup? Also seems like most prefer to upgrade to the 7730 and DIS...I suppose I should look into this further. Is this an easy upgrade or will there be a headache when it comes to getting it up and running and tuning?
Is it worth the hassle and work? A good question. I did a lot of work to improve my top end and the results are pretty good. I did a cam, custom intake, plus lots of porting on the lower intake. I did not port the heads.
I chopped down a middle intake, and welded large plenums with dual throttle bodies on them...flowed really well, but the dual TBs were a hassle. I went back to a single, and it's way easier to drive and maintain, but doesn't flow as much (Butt-o-meter), so I can tell you from experience improving the intake makes a difference.
For your particular options, with the 2.8, I think you would be good with a dawg style stocker or a camaro 3.4 intake, or a truleo if you can get one. That should support increased flow through your worked heads, valves/camshaft etc. It's always best to adress the whole system at once, rather than expecting an extreme upgrade in only one area to improve much.
Worth the effort? I don't know. I just know I did everything I could to give the old girl a chance to make some power.
About the DIS, search here....there are threads about it. Like I said above, you need a crank trigger. After that it's just settings in the 7730. It depends on what code you use in the 7730 as to the settings.
You can look at my thread about adding it to a 7730 running $59 code:
Is it worth the hassle and work? A good question. I did a lot of work to improve my top end and the results are pretty good. I did a cam, custom intake, plus lots of porting on the lower intake. I did not port the heads.
I chopped down a middle intake, and welded large plenums with dual throttle bodies on them...flowed really well, but the dual TBs were a hassle. I went back to a single, and it's way easier to drive and maintain, but doesn't flow as much (Butt-o-meter), so I can tell you from experience improving the intake makes a difference.
For your particular options, with the 2.8, I think you would be good with a dawg style stocker or a camaro 3.4 intake, or a truleo if you can get one. That should support increased flow through your worked heads, valves/camshaft etc. It's always best to adress the whole system at once, rather than expecting an extreme upgrade in only one area to improve much.
Worth the effort? I don't know. I just know I did everything I could to give the old girl a chance to make some power.
Chay
Yeah it's one of those things...is it worth it or not I guess that is all in what your expectations are...big or small really doesn't matter...anything will be better. I have a spare stock upper that I originally planned on doing the DAWG mod...have a pending deal on lowers and a set of heads. This (all P&P work) is something I will do myself, probably over the Winter and then swap the parts out next Spring/Summer. The Camaro intakes are pretty cheap so picking up one isn't a big deal...may play with both.
Just saw you reply about the 7730 & DIS Now need to decide on the 7730 & DIS upgrade...again worth it if I stay with the Fiero intake vs the Camaro intake...hassles, headaches, tuning issues, etc. or is it an easy upgrade ?
I'd say if you're changing the intake you're going to have to re-tune anyway. The DIS spark shouldn't require re-mapping, it should just be better, so no biggie there.
Do you use a wideband 02 now? There are a lot of options for tuning, yeah if you haven't done it before there is a learning curve.
I think for all the effort I would have been better using a 3400/3500 so that for all the work, there is a larger return on the invested time. Or a 3800T, or a 3.4TDC, etc etc. The 2.8 is a bit of a dinosaur.
Scott87GtTurbo: You are crazy close to me I'm in Frederick, and my In-laws are in Taylorsville (RT 26 & RT 27) can I come take a look at that MillerWoods setup sometime?
Scott87GtTurbo: You are crazy close to me I'm in Frederick, and my In-laws are in Taylorsville (RT 26 & RT 27) can I come take a look at that MillerWoods setup sometime?
Sure thing...I'm further down 26 in Eldersburg just off 32. My mom & dad live in Taylorsville just off 27 towards Mt Airy.
I'd say if you're changing the intake you're going to have to re-tune anyway. The DIS spark shouldn't require re-mapping, it should just be better, so no biggie there.
Do you use a wideband 02 now? There are a lot of options for tuning, yeah if you haven't done it before there is a learning curve.
I think for all the effort I would have been better using a 3400/3500 so that for all the work, there is a larger return on the invested time. Or a 3800T, or a 3.4TDC, etc etc. The 2.8 is a bit of a dinosaur.
Chay
Currently don't use a wideband O2 on either of my turbo cars but have plans to going to a wideband on the TTA for sure. I have done some very mild tuning on my TTA through the Turbotweek chip and some tuning on my sons Talon AWD TSI with a Inovative LM1 wideband/reader and Apexi SAFC. Yeah the 2.8 is a dinosaur but again the Fiero isn't my main High Performance fix...the TTA covers that and then some. It runs pretty good as is but the setup is very dated when it comes to the turbo kit and can definitely be made better so I figured if I could squeeze another 15-20+ HP out of it I'd be over 200 rwhp. No emissions so all that crap can come off...EGR, CAT, etc....stock air box sucks and since i have functional side scoops a CAI is easy. If I P&P the intake and heads, do the DAWG mod and install the optimized and bored out TB I did a couple years ago, maybe a set of 1.6:1 roller rockers it should be achievable at the 10 psi I'm currently running. I have a couple small intercoolers I have been thinking about trying and may ad a methanol injection kit to keep the knock under control...maybe try a couple more psi 12-14? Currently running 26 psi on my 89 3.8L Turbo Trans Am on 93 pump gas with a Alkycontrol progresive methanol injection kit without any issues for the last 5 years driven on the street...and at the track the car has gone 11.17 @ 124 with 1.48 60' still stock heads and cam
look around and ask on 60degreev6.com if your not that worried with keeping "stock" look, and possibly changing pistons, you could do an aluminum head swap that would well outflow any iron head... or if your looking for a 'big' upgrade goto a full 3100/3400, bit more work, but a 3400 with a turbo upgrade and you could be at 300+ hp heres a pic of mine (taken by the PO, all the ones I took are on my laptop :/)
[This message has been edited by hookdonspeed (edited 11-28-2013).]
user La Fiera is offering CNC ported heads for ~$400 - that's dirt cheap. Don't believe anyone who says you can't do anything to the iron heads to make them flow...
To confirm, the CNC-ported heads you mentioned are cast iron, available from LaFiera for around $400, and start out either as the cast iron heads found in 2.8L Fieros, or as the (same) cast iron heads found on `93 - `95 3.4L V6 Camaros and Firebirds?
yeah...no problem. We'll have to set something up when the weather clears up a bit.
Keep me posted too, I'm down that way all the time as well. Does Tony (lowfierogt) still live around there? Been to his house a couple times, but that was a few years ago. Haven't heard from him in a while.
ahhh that's curtis' old Z24 Iron heads with the intake vane completely removed, the 3.4 intake also had extensive work done to it, iirc involved cutting and welding. That baby put down about 500hp too \m/.
Iron heads with the intake vane completely removed, the 3.4 intake also had extensive work done to it, iirc involved cutting and welding. That baby put down about 500hp too \m/. 
