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Replacing exhaust system for more power? by st88fiero
Started on: 09-11-2013 11:30 PM
Replies: 11 (596 views)
Last post by: st88fiero on 09-17-2013 06:48 AM
st88fiero
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Report this Post09-11-2013 11:30 PM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
I recently purchased a very clean 38k mile 88 GT 5 speed. My intention is to keep the car as original as possible it's basically a show car.

Like everybody else, I would like a bit more power. The only mod this car has now is no CAT (It came to me like that).

I am never going to change the motor (this car is in too good of shape, and I only drive it to shows, so it will be a long time before the motor needs to be done anyway, probably after I am dead!),

I was speaking to Phil at the Fiero Store today and he suggested that the way to get the most out of the stock 2.8 is to run a full exhaust system, including manifolds and use the hypertech chip.


The FS has replacement manifolds that are heat coated and an Ocelet system, it is very pricey but is it worth it?

Has anybody here used these parts?....and if so were the power gains noteworthy?

Do the heat coated manifolds really reduce engine compartment tempetures?

And lastly, is installing the manifolds a total nightmare on these cars? I would be bringing it to a shop to have done (I'm not a mechanic like many on this site) but is it possible to install them from bottom or car while up on lift?

I'm seriously thinking about it, but before I drop $1200 on parts, would love some opinions on it.

Thank you for all replies....
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CowsPatoot
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Report this Post09-11-2013 11:45 PM Click Here to See the Profile for CowsPatootClick Here to visit CowsPatoot's HomePageSend a Private Message to CowsPatootEdit/Delete MessageReply w/QuoteDirect Link to This Post
First, you will probably notice a larger difference from swapping to ported manifolds or headers than with the rest of the exhaust. The replacement manifolds at the FS are simply replacements, and will not improve performance. I can't comment on temps though, I have never made the comparison. Watch for a set of Sprint or Truleo headers...they come up from time to time. Even the old FOCOA ones would be an improvement. Or, port the manifolds you have (sorry, going to make you search for details on how...I would have to search it myself if I wanted to do it).

The front manifold requires approval from Congress to replace. Seriously....it CAN be done in the car...but I think it would be easier to pull the head. Of course...saying it can be done is assuming you don't break any bolts when removing the old one.

Skip the chip.

Regardless...you are unlikely to notice any of these changes with the butt-dyno.
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trotterlg
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Report this Post09-11-2013 11:50 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
But if you do some work on the exhaust you will probably "think" is is faster. (It really won't be). Larry
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James Bond 007
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Report this Post09-12-2013 08:43 PM Click Here to See the Profile for James Bond 007Send a Private Message to James Bond 007Edit/Delete MessageReply w/QuoteDirect Link to This Post
I agree....port the exhaust manifolds.
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cam-a-lot
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Report this Post09-13-2013 05:00 AM Click Here to See the Profile for cam-a-lotSend a Private Message to cam-a-lotEdit/Delete MessageReply w/QuoteDirect Link to This Post
By taking off and porting perfectly good manifolds for miniscule gain...2-5 HP at best... you are asking for broken head bolts and other grief. The Hypertech chip has been discussed a million times on the forum and proven to be worthless. I have one that came with one of my cars and you can have it for free if you pay for postage, but it is honestly a waste of time

The car is heavy and slow. It looks and sounds cool. If it is a show car, just enjoy it- the stock 2.8 Fiero has one of the better sounding exhaust tones out there. It is an ancient engine design and many here have put tons of time and effort into making it perform better (different intake, exhaust, port and polish, etc) and they would still lose in a race to my wife's Toyota Sienna minivan full of 3 spoiled kids. If you ever blow the engine, then a 3.4 swap would add some ponies with very little fab work necessary.

Removing a catalytic does nothing for performance if the cat is working properly on a factory motor. All it does is needlessly pollute the environment and annoy the people having to breathe behind you in traffic. Not sure why people remove them...

Just an opinion.... Enjoy your ride!

2011 Toyota Sienna 4800 lbs..... 15.8 sec 1/4 mile While Watching Hannah Montana in the back seat

[This message has been edited by cam-a-lot (edited 09-13-2013).]

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Arns85GT
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Report this Post09-13-2013 10:32 AM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Practical track experience will tell you that removing an old CAT, porting your exhaust manifolds and Y will give you better performance, period.

End of story. Having done it I can tell you that you will pick up 5-8 hp. at the wheels and on a care that puts down 115 at the wheels, that is significant and cost effective.

Have fun.

Arn

(15.47 sec. on the quarter mile)

[This message has been edited by Arns85GT (edited 09-13-2013).]

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DaytonTD
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Report this Post09-13-2013 05:10 PM Click Here to See the Profile for DaytonTDClick Here to Email DaytonTDSend a Private Message to DaytonTDEdit/Delete MessageReply w/QuoteDirect Link to This Post
I wouldn't waste time or money, I have done pretty much everything besides stroke and turbo my V6 and I think it feels the same as when I got it originally. This includes FS headers, ocelet exhaust, 262 Cam, 1.6 rockers, bored .040 over, FS performance engine rebuild kit, FS chip etc...
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Arns85GT
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Report this Post09-13-2013 06:41 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
The only thing helping your build is your headers.

The 1.6 rockers won't help if you don't port the heads.

Porting the heads won't help with a stock intake. The stock intake restricts everything down stream. Even a bored throttle body isn't enough

Now the Trueleo setup covers more territory and makes porting an 1.6 rockers a real plus.

In my case I started with a 390 cfm carb and a ported exhaust. It made a big difference.

Arn

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sco77
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Report this Post09-13-2013 06:52 PM Click Here to See the Profile for sco77Click Here to Email sco77Send a Private Message to sco77Edit/Delete MessageReply w/QuoteDirect Link to This Post
With the stock engine I felt a noticeable improvement by porting the exhaust manifolds, so I could only imagine headers would atleast give a noticeable improvement. Maybe run higher octane and advance the timing more.

------------------
86 Fiero GT 4spd - L67 swap: VS cam, GenV Build Progress
98 GTP - Some mods

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DimeMachine
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Report this Post09-14-2013 07:53 AM Click Here to See the Profile for DimeMachineSend a Private Message to DimeMachineEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by cam-a-lot:

By taking off and porting perfectly good manifolds for miniscule gain...2-5 HP at best... you are asking for broken head bolts and other grief. The Hypertech chip has been discussed a million times on the forum and proven to be worthless. I have one that came with one of my cars and you can have it for free if you pay for postage, but it is honestly a waste of time

The car is heavy and slow. It looks and sounds cool. If it is a show car, just enjoy it- the stock 2.8 Fiero has one of the better sounding exhaust tones out there. It is an ancient engine design and many here have put tons of time and effort into making it perform better (different intake, exhaust, port and polish, etc) and they would still lose in a race to my wife's Toyota Sienna minivan full of 3 spoiled kids. If you ever blow the engine, then a 3.4 swap would add some ponies with very little fab work necessary.

Removing a catalytic does nothing for performance if the cat is working properly on a factory motor. All it does is needlessly pollute the environment and annoy the people having to breathe behind you in traffic. Not sure why people remove them...

Just an opinion.... Enjoy your ride!

2011 Toyota Sienna 4800 lbs..... 15.8 sec 1/4 mile While Watching Hannah Montana in the back seat



1. It is true that you are asking for broke exhaust studs on a 2.8. They can be a pain in the ars to fix on the car.
2. I have had Fieros for 20 years. I started with the manifold porting (broke a couple studs) and did not really notice any power gain.
3. I went with a slightly bigger cam - and did not really notice a power gain. Yes you are gaining a few HP but it is not changing the cars power to weight ratio much. 2650/135 = 19.62 lbs per HP. 2650/145=18.2 lbs per hp.
4. IIf you like your fiero, chances are you bought it because it is sporty looking. If you have not done so, you owe it to yourself to take a spin in someones 3800 Fiero. 2750lbs/240hp =11.45 lbs per HP = Holy Crap! You may find that you like it a LOT. I have had Fieros for 20 years and IMO, the 3800 is the engine that belongs in the Fiero. Sorry, I know you did not ask about swaps, but when a person feels so strongly about something, it is hard to control your enthusiasm.


------------------
84/87 NB, 3800SC, E-85, VS Cam, 2.8 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, Regal GS Gauges, S-10 Brake Booster. 1/4 mile -11.906 at 111.93mph

[This message has been edited by DimeMachine (edited 09-14-2013).]

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st88fiero
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Report this Post09-16-2013 10:55 PM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you all for such good insight on this topic. After reading all the replies(I really do like the mini-van comments!, sad but true) I think with the very modest gains you can get form this stock power plant, it's really not worth it to mess too much with it, just enjoy it for what it is, and it still handles great!

I do have to say, if you whole shot the car at 4k rpm and powershift through the gears, the car does get up and go, and it really does not have enough power to blow up the tranny while your foot is pinned to the floor while rowing through the gears, so , if I want to go fast (well sort of) that is what I will do instead of spending 2k.....or I'll just jump in my 87 5.0 Mustang and rip off a few quarter mile runs and be happy to have my pretty little girl Fiero to cruise around in....I have been truly amazed how much attention these cars get, so that's all that really matters, as long as you look cool ;-), right?

[This message has been edited by st88fiero (edited 09-16-2013).]

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st88fiero
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Report this Post09-17-2013 06:48 AM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by DimeMachine:


4. IIf you like your fiero, chances are you bought it because it is sporty looking. If you have not done so, you owe it to yourself to take a spin in someones 3800 Fiero.




Is there anyone in the Long Island aera that has a swap done that I could see in person?
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