Hello all,

From my understanding the stock Y-Pipe on the V-6 exhaust has a major restriction.
I'm currently working on a 3.4L PR swap on my 88GT and was looking at purchasing this aftermarket CROSSOVER PIPE from the FieroStore.

Does anybody know if this aftermarket pipe flows any better (or has the same blockage issue) as the stock pipe?

I was also considering picking up a 1988 V6 PERFORMANCE HEADPIPE Part # 54402 since the pipe leading up to my CAT has a major leak...

Thoughts anybody?

Thanks a bunch!

I've installed those crossover pipes and they are way better than the stock Fiero crossover pipe. Both crossovers use 2" pipes but the Fiero Stores pipe is a full 2" all the way through including at the Y point junction of L and R. In contrast the stock Fiero crossover necks down to about 1" per side at the Y. IMO VERY restrictive.
If you want a free flow 2.8/3.1/3.4 exhaust system you are not going to do it with the stock Fiero crossover pipe. That pipe and the CAT are the most restrictive elements in the exhaust. That's why I also recommend using a straight pipe and ported exhaust manifolds for top efficiency..

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Well that "performance headpipe" is cheap at $40, but I had a straight pipe on my 88 V6 for many years and last summer replaced it with a catalytic converter becasue I could not stand the stink of the un-catalyzed exhaust anymore. I spent a bit over $200 to make my intermediate section with converter, but it was worth every penny to me because my car is a whole lot cleaner now (doen't stink so bad when the engine is running).

I purchased an 88 headpipe from the Fiero Factory to get the flange and spring hanger.
Got a Magnaflow converter from Summit.
Purchased some 304 16 gague straight pipe and a J bend from Burns Stainless.
Cut the pipes to size, got the ends flared/expanded appropriately, got it welded up, and installed it.
Very happy with the end result. The Magnaflow converter flows much better than a stock unit would, and did not diminish the sound of the exhaust.

Thanks for the responses guys!

And thanks for sharing your insight into these pipes from the Fiero Store!

I ordered up both pipes for now. lateFormula thanks for sharing your experience with running a Fiero without a CAT. I probably would prefer to run a high flow cat, but I'm running so low on funds at this point in my build that I'm going to give it a shot without first. If I start suffering from asphyxiation I'll definitely install one down the road. But at least I now know that this can be an issue. Thank you!!!

Dennis LaGrua thank you for explaining the differences between the stock pipes and the Fiero Store pipes... This is exactly what I needed to know...

Thanks a bunch for taking the time to answer my questions guys and have a great weekend!!!

Shown below are two classic "Before" versus "After" photos of an otherwise stock, but cut-up Fiero V6 exhaust Y-pipe (a.k.a. "crossover pipe") that were provided us elsewhere by fellow PFF member, Dodgerunner. That pre- versus post-porting comparison should provide you an idea of the inefficiency of the Fiero V6's factory-original, exhaust Y-pipe:


Based on those photos from Dodgerunner, I'd expect your 3.4L engine swap would indeed benefit from the installation of an improved Y-pipe in your Fiero.

For my own 3.4L engine swap, I purchased a custom Y-pipe from Trueleo Creations, which for heat retention and durability, I later had ceramic coated, like the Sprint headers are on my 3.4L engine swap. By the way, those Sprint headers (available from The Fiero Store) already come ceramic coated, and seem to last forever, so I'd think a ceramic-coated Y-pipe would do the same.

Thanks again project34!

Yes, it was that photo I've seen posted several times that made me consider replacing the infamous Y-Pipe...

Somewhere down the road I will probably toss in a better exhaust, but I'm a little short on cash with my 3.4 swap coming to a close and just want to squeak by as cheaply as possible at this point.

Here's where I'm at;

88GT
7730
3.4L w/272 CAM
Ported Upper Intake
Larger Throttle Body
Exhaust Manifold Logs (WCF)
Crossover Pipe (FS)
Head Pipe (FS)
Power Pulley Kit (Rodney D)
TransGo Shift Kit (125 Auto)

Hopefully, even with cutting a few corners on the exhaust I will be able to get some good performance out of this setup. Did I cover most of the bases and bottlenecks on this swap?


Were you happy with your 3.4 swap? I'm still unsure what to expect... There's so much love and hate for this swap on this forum it's difficult to decide on whats what...

Thanks again everyone!!!

quote Originally posted by 1Shamrock: Thanks again project34!

You're welcome, 1Shamrock.

quote Originally posted by 1Shamrock: Did I cover most of the bases and bottlenecks on this swap?

Candidly, I think you have addressed two bottlenecks (the cam and the Y-pipe), and although not really addressing an intake or exhaust "bottleneck" per se, your swapping out the stock computer for a -7730 makes sense to me because it should help substantially expand the electronic tuning possibilities for your Fiero.

Unfortunately, I don't think you've successfully addressed at least four other bottlenecks which need to be rectified before the H-272-2 cam in your 3.4L engine swap can realize its full potential.

From the wording of your question above re "bottlenecks on this swap", it sounds like you may have missed my 3rd post at your other thread, "3.4L PR / TH-125 Torque Converter?" ( https://www.fiero.nl/forum/Forum2/HTML/121172.html ), where I've already discussed those bottlenecks. Thererfore, rather than repeat here that thread's 3rd post of mine, I've here simply called your attention to it.

Thanks again for responding Project34!

I gave the post that you pointed out another read through and I thought that maybe I was in the clear on using a 272Cam with the responses from Hudini... Although, he does mention later that he is using a 260Cam (like you had suggested) on an automatic transmission.

From what I gathered (and please correct me if I'm wrong), I believe that I might have only covered 3/4 bottle necks...
Below is a link of the Intake/TB that I am using for now...
https://www.fiero.nl/forum/Forum4/HTML/058295.html

That with the Head Pipe/Crossover Pipe and WCF Manifold Logs has left me hoping that this will be enough for the engine to breath well to get some performance out of it...

This probably isn't the best solution, but hopefully it'll tie me over until I can afford a Truleo or Street Solutions Intake and a real exhaust system...
I did see a Truleo listed in the Mall yesterday, but it went quick...


Another question regarding the Crossover Pipe from the Fiero Store... Do I need the Heat Shield from the original pipe?

quote Originally posted by 1Shamrock: From what I gathered (and please correct me if I'm wrong), I believe that I might have only covered 3/4 bottle necks...

To keep things simple, I'm going to focus only on six impediments to higher-RPM performance with a "basic" pushrod 3.4L engine swap, and suggest at least one potential fix to address each, shown below in parentheses (==> ):

...Stock Camshaft (==> aftermarket cam with greater duration and lift)
...Stock Intake Manifold (==> Trueleo for EFI, or Edelbrock for carburetion)
...Stock Throttle Body (==> professionally bored out stocker, or different and larger throttle body model)
...Stock Exhaust Manifolds (==> Trueleo or Sprint headers)
...Stock Y-Pipe (==> Trueleo or Fiero Store or ported)
...Stock Cylinder Heads (==> professionally ported and shaved)

Just in terms of parts you've purchased --- as opposed to whether they'll work together well with everything else or not --- three address those impediments fairly clearly: the aftermarket camshaft, the larger throttle body, and the aftermarket Y-pipe. Three do not: the ported stock intake manifold (does not appear to relieve the crimp in the neck of the stock Fiero intake manifold, nor does it shorten the Fiero manifold's overly lengthy intake runners), the replacement exhaust logs, and the unmodified, stock cylinder heads.

Keep in mind that the breathing limitations of components other than the camshaft are less of an issue with a milder cam (e.g., a Crane H-260-2 or a Comp Cams 252H) because a milder cam doesn't need to be matched with parts permiting as high a level of increased breathing ability at greater RPMs as would a more aggressive cam (e.g., a Crane H-272-2 or the Crower HDP290 cam).

quote Originally posted by 1Shamrock: Another question regarding the Crossover Pipe from the Fiero Store... Do I need the Heat Shield from the original pipe?

I've found them to quite candid in the past, so I suggest asking that question directly of The Fiero Store's technical support staff via email ( info@fierostore.com ). However, I'd clearly specify which type of crossover pipe you're asking about, be it the regular one, or what The Fiero Store calls their "heat coated" one. If the latter is ceramic-coated, I'd think you'd be less likely to need the heat shield. A big side benefit of ceramic coating is it makes exhaust parts subjected to high heat --- like headers and crossover pipes ("Y-pipes) --- last seemingly forever.

I've kept and plan to keep my Fiero for a l-o-n-g time and that is why I had my Trueleo Y-pipe ceramic coated.

Thanks Project34!

I'm taking notes here on all of the great information you have been kind enough to share with me so far... I'm definitely planning on replacing the intake manifold but I picked up this other one to get me by in the mean time. I figured it had to be better than the stock one, but with the crimped neck I now know it has to go! Headers are also on my to do list but I might hold off until the spring of 2013 and replace the entire exhaust in one shot...

Concerning having the heads ported...
I did some searching online and found a company called A.R.I. that offer this service. Although, they list about a dozen options and the prices are all over the board...I also seen some folks discussing Falconer heads as well, but couldn't find a place that sold them. And a few months back, the FieroStore used to carry a set of performance heads but I don't see them listed anymore...
If you were to point a newbie in the right direction on where to have this done and had to toss out a fair, ball park price to have this done... What would you suggest? And let's say that I absolutely had to use the refurbished stock style heads for the summer and then replace the heads with ported ones in the fall, is that even possible with the engine still packed inside of the Fiero? The reason I ask is because from what I understand the heads on the 2.8 and the 3.4 are identical. So I have an extra set to play with...
Of course, I would be willing to accept the heads off of your 3.4 if you're willing to donate them... Heck, I'd even pay for shipping... lol.. jk...

Thanks so much for all of your help on this! I can't tell you enough how much I appreciate it!

quote Originally posted by 1Shamrock: is that even possible with the engine still packed inside of the Fiero?

Yes. I've done it a couple of times.

Thanks lateFormula!

That's good to know that it can be done... Was it a terrible ordeal to complete that task?

quote Originally posted by 1Shamrock: Thanks Project34! Concerning having the heads ported... I did some searching online and found a company called A.R.I. that offer this service. Although, they list about a dozen options and the prices are all over the board...I also seen some folks discussing Falconer heads as well, but couldn't find a place that sold them. And a few months back, the FieroStore used to carry a set of performance heads but I don't see them listed anymore... If Thanks so much for all of your help on this! I can't tell you enough how much I appreciate it!

If you're on a budget and/or not building an all-out race engine, head porting is -if not done yourself- is not very cost effective. When we tested our first intake manifold on the flow bench we found that it would support over 300HP with stock iron heads. Yes you can see some gains, but not enough to be worth the bother. The stock intake and exhaust negate getting the full beny from near all mods especially above 4.5 k. When I did my first 2.8 build I went with a better cam, some DIY head work, higher comp pistons, simple headers and so forth and was totally disappointed come dyno day. I gain may 35hp and no additional RPM. It just went insanely rich above 4k , so much so the wideband could not read it. Port your headers and Y pipe and wait until you can get either a carb setup or a better intake. When building for power and/or gas mileage always address the engine's main faults first.

quote Originally posted by 1Shamrock: Was it a terrible ordeal to complete that task?

I didn't consider it to be a very difficult job. But you are removing a lot of parts that you need to keep organized so that nothing goes missing when you reassemble. Lot's of fasteners to keep track of - I use Ziplock sandwich bags and use a separate one for each set of fasteners for an item. I also use 3x5 notecards to jot down what each bag of fasteners is for - put the notecards into the bags as you go. Also there are some specialized tools you will need to do the job right and make it easier.

Would a modified stock Y-pipe be as good as The Fiero Store's new one?

Jonathan

A Trueleo header(s) + 2.5" exhaust t is the single biggest bang you will get out of a 3.4 swap.

quote Originally posted by 1Shamrock: Concerning having the heads ported.... ...If you were to point a newbie in the right direction on where to have this done....What would you suggest?

The gentlemen I've dealt with for engine work almost never deal with the general public.

However, although he currently has a Chevy V8 Fiero, fellow Pennock's and N.I.F.E. (Northern Illinois Fiero Enthusuasts) member, Oreif, might prove an excellent source for a recommendation as to whom you could use for professional porting of your Fiero 2.8L or "Camarobird" 3.4L cylinder heads. (And yes, in regard to another inquiry you had, those two sets of cylinder heads in stock form are identical.)

I suggest contacting Oreif for a recommendation re a source for professional porting of your cylinder heads, for several reasons:

• Oreif several years ago compared two pushrod 3.4L engine swap build-ups for Fieros.
  
• Both build-ups employed the same cam you have, the Crane H-272-2.
  
• Both build-ups' 2.8L/3.4L cylinder heads were, IIRC, professionally ported.
  
• One engine was mated to a manual transmission, and happened to employ a Trueleo intake manifold and EFI.
  
• The other engine was mated to an automatic transmission, like your 3.4L engine will be, and happened to employ an Edelbrock intake manifold and a Holley carburetor.

In short, both engine swaps were built up somewhat differently, but with various engine components (e.g., heads, intake, and exhaust) better matched with each engine's Crane H-272-2 cam.

Incidentally --- and again, IIRC --- each of the above 3.4L engine swaps produced around 230 horsepower overall, and around 200 horsepower at the rear wheels.