Ok cheap things is to one tune up always good then port the exhaust manifolds. Other things are more expensive. Weight reduction and maybe swapping to a getrag if your running the 4 speed for better fuel efficiency
cause this car is nice its red super clean 101,000 but there all highway which is great but i have done alot of research on this car and i found a website that puts alot of points out there http://www.fierofocus.com/a...0-%20Lee%20Brown.htm
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02:42 AM
ktthecarguy Member
Posts: 2076 From: Livonia, MI USA Registered: Jun 2007
A quick fix would be to replace your spark plug wires and plugs. If they are more than a few years old, (or original) they are probably pretty tired by now. I would also recommend an MSG ignition coil while you are at it. You can then open up the spark plug gap a couple points to increase the size of the spark.
That should wake up the engine a little bit. I did all this on my V6, and now it like to rev past 4,000 RPMs. It never used to.
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03:17 AM
James Bond 007 Member
Posts: 8872 From: California.U.S.A. Registered: Dec 2002
Port your exhaust manifolds allso Read Here: V6 power gains
A number of readers of this list have ask various questions about what they can do to improve the performance of their V6 powered Fiero's. The following was excerpted from "FIERO KITS-ALL FIRED UP!" by Herb Adams. Herb Adams has raced a variety of Fieros over the years, and currently sells some of the best suspension upgrade/racing parts for Fieros (see Peter's Fiero WEB page for address and phone number). The article was published in the September 1991 issue of Kit Car. If you would like (and I find the time) I'll enter the remainder of the article that covers tires, suspension and handling. (A quick tease, Herb Adams on Fiero tires: The stock rear fenders have room for Goodyear ZRS 255/50x16 tires on 16x9 wheels, although 255/50x16 on 16x8 wheels will also provide improvement.)
Even the fuel-injected V6 Fiero provides only average acceleration and top speed, so many Fiero owners want to know what they can do to increase their engine's power level, As part of the racing program, I conducted a series of power development tests to determine ways to improve the output of a Fiero V6 engine. Racing applications were at the IMSA Firestone Firehawk Events, which allow open exhausts, so most of the testing was done in this manner. The performance improvements, then, should be proportional of those found on a car with a street-legal exhaust.
Before I made any changes, the stock V6 engine was dyno-tested "as installed" with the factory's exhaust, air inlet, and electronics management systems. As indicated by the power curves and the dyno data sheet, the Fiero V6 engine produced a peak corrected horsepower of 110 at 4500 rpm, significantly lower than the advertised 125hp. The difference might be accounted for by differences in dynos, but the important thing for the evaluation was to establish a good baseline.
Blueprinting an engine refers to the practice of bringing all the internal specs and tolerances up to those published in the MVMA book. The process is simple, but time-consuming because the engine must be removed from the car and completely disassembled, My race team machined the block to provide .005-inches of piston fit and to produce the minimum deck height allowed. We also decked the heads to provide minimum chamber size. The bearings were fit to .0020 / .0025-inch, and all the rotating parts were precision balanced. Head porting is not allowed, but a precision valve job was done to ensure the best possible air flow through the heads. Out dyno testing showed that the blueprinting work increased peak output 3 horsepower at 4500 rpm and 17 horsepower at 5500 rpm. Less friction and better breathing help at higher engine speeds, so if you're interested in using more rpm, it would be worth the effort. Note that the test on the blueprinted engine was done with the stock intake and exhaust systems.
Open exhaust tests showed a six horsepower gain from 4500-5500 rpm. This system replaced the stock muffler and converter with a six-foot long, two-inch diameter straight pipe. Such a system is to noisy for the street, but it does show potential with an improved street-legal system. The open exhaust test was run with the stock exhaust manifolds and with the stock air inlet system.
The next stage of engine development involved a high-lift camshaft. Most stock engines will see a power increase with more valve lift. We needed to keep the idle equally smooth and the emission levels the same as the stock engine, so we didn't increase valve timing. With a higher lift cam, the valves are opened faster as well as farther, but the opening and closing point are the same as stock. A high-lift cam increased the power level by 15 horsepower at 5000 rpm and 14 horsepower at 5500 rpm.
The level of increase might be less on a car with a street legal exhaust, but the effects should still be rewarding. Installing a new camshaft in a Fiero with the V6 engine requires removing the engine, so some owners might want to switch to 1.60 rocker arms instead. The performance improvement will be slightly less, but the installation is easier.
Inspection of the Fiero exhaust manifolds showed some manufacturing related problems that severely restricted flow of exhaust gases. The attached sketch shows where the manufacturer left excess metal inside the manifolds. After these edges were ground away, power increased eight horsepower at 5000 and 5500 rpm. You can eliminate these edges on your Fiero exhaust manifold with a small die grinder.
FLANGE __x_________x__ Grinding off excess metal |_______________| in the exhaust manifold | | can result in a significant | | power gain. (Problem is at | \ points marked with x's) \ \ __________________\xx xx\_______________________
-------------------------> Flow of exhaust Gases ______________________________________________________ COLLECTOR FIERO V6 DYNO DATA CORRECTED HORSEPOWER (read the RPM,then down)
(Approximated from chart) 3500 4000 4500 5000 5500 RPM's
Ported Exhaust manifolds 109HP 124HP 135HP 143HP 139 HP
Installed High-lift cam 103HP 117HP 126HP 135HP 132 HP
Blueprinted Engine w/Open Exhaust 99HP 112HP 120HP 119HP 118 HP
Blueprinted Engine w/Stock Exhaust 96HP 108HP 113HP 113HP 111 HP
Pure Stock Engine w/Stock Exhaust 94HP 107HP 110HP 107HP 94 HP WHAT YOU SHOULD LEAVE ALONE
In searching for more power, my race crew tested the Fiero V6 engine on the dyno without the stock air cleaner and inlet system, and we were surprised to find that this produced no change in power. Apparently, the Pontiac engineers did a good job on these parts because they work well, even though they look restrictive.
Another alteration that made little or no difference was cam timing. Advancing or retarding both the stock and high-lift cam resulted in power level changes of only one horsepower, more at some rpms and less at others. This shows that both cams are optimized at their normal position
Testing various PROM (Programmable Read-Only Memory) computer chips in the electronic engine management system also showed that the Pontiac engineers did their job well. Different PROMS with various fuel/air ratios and timing curves showed no power improvement. We did choose a PROM with less full throttle enrichment at high rpm to help our fuel economy during the endurance races. This change gave us about five minutes more racing on a tank of fuel, so we used it for many events. The last race was run at night. The weather was cool so the air was dense. After about an hour of racing, we burned a piston from being too lean. We weren't too happy, but it showed again that the factory electronic engineers usually know what's best for the average customer.
Owners of Fiero-based kit cars can make a number of performance improvements with a relatively small investment of time and money. Using any of all the above modifications will substantially improve speed and handling. Like most things, though, the results will be proportional to how much effort and money you choose to invest.
================================================================================================================================================ More info can be found at this link but it's for a truck,the info can easily be adapted to a Fiero. http://www.4x4wire.com/tech/60degreeV6/index.htm
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10:22 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
yea but see i dont have time or money to do that kind of stuff or i would
well - theres maybe 10-20 HP to be gained with bolt-ons. that is it. after that - it is time & money a swap is MUCH cheaper in the long run. most folk want at leat 200HP. the only way that is possible with the 2.8 as it sits is by removing the fuel injection system, and going with a carburator. the reason this is, is because the stock intake is WAY to restrictive. it can only breath in at most 150 or so HP's. most dont like this idea. so - next step - is engine swap. a 3.4DOHC or a 3.8/3800 will pop you straight to 200HPs. and, they are not as difficult as you would imagine. yes - they are WAY overwhelimng at first - especially when you start to hear all thats needed. but - one step at a time, and it will come together.
and - it is VERY important to have a actual daily driver other than your project car. you are basicly guaranteed to not get anywhere if the porject car is the daily driver.
The quickest and easy way (bolt-on) to get more power and gas milage is to get rid of the stock intake. It not only restricks airflow and thus power, it makes the engine run rich above 4k and more rpm you try for the richer it gets, rich=poor gas milage.
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04:55 PM
BabyVet Member
Posts: 1173 From: Kansas City, Kansas Registered: May 2008
i suggest k&n air filter or get some tube and make up a short ram intake with a cone filter that will help a little and then if you want to spend a little bit of money i suggest going to the trueleo intake
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10:57 PM
linuxpowered88 Member
Posts: 1220 From: Johnson City , TN , USA Registered: Sep 2007
The stock air filter box is a very good setup and will flow more air then a stock intake will need. You can put a K&N in there but dont do away the setup for a cone type. You lose more power that way inasmuch as you will then be proviving hot (thinner) air the engine. Yes it may look better, but wont work near as good as the stock one with its outside air supply.
Agree. The only beneficial K&N upgrade is the CRX intake with the filter placed in the wheel well. That said, I have a good friend who was pumping a turbocharged v8 using the stock Fiero intake. Think about that one for a sec. before you put out cash. I think he removed the water separator only.
Inexpensive? Well, that is not a great way to get more power. Porting everything is a start. You'll need some carbide burrs and a Dremel setup. The cost for the tools is about $100.
You'll need some new gaskets when you take it apart. More $.
Then you start porting. This means the exhaust manifolds, Y, intake manifolds, then heads. It means removing the valves and re-seating them.
All the while, the $ keep rolling out. If you get good sparks, wires and high output coil, good alternator and a careful tuneup, you will see improved performance. That is your cheapest power adder.
I want to talk about this part of the testing results posted above.
"Open exhaust tests showed a six horsepower gain from 4500-5500 rpm. This system replaced the stock muffler and converter with a six-foot long, two-inch diameter straight pipe. Such a system is to noisy for the street, but it does show potential with an improved street-legal system. The open exhaust test was run with the stock exhaust manifolds and with the stock air inlet system."
A 6' pipe is a no-no. It sets up incorrect pulses in the pipe and robs power. You need less than 6'. This is well documented.
In my case, I used 2.5" pipe with a ported Y and a Muffler in the CAT position. When I finish my new system it will be true duals. But,that will be another story.
the cone filters are good if you want less horsepower and worse gas milage , the stock setup is dyno proven ,, The best performance modification for the V6 fiero is to port the exhaust all you have to do is look at the stock exhaust manifold..I wish i could post photos ..I purchase 2 sets of ported exhaust manifolds from forum members the port jobs were terrible ,incomplete I imagine most port jobs are not completed as they should be it takes about 2 hours per port unless you have hi speed air tools Proper porting of the stock exhaust manifold ,the Y pipe and open up the exhaust with a thrush or cheery bomb will net you 10 to 15 horse power this is a lot for the V6,, this will increase reliability, GAS milage and help the engine run cooler . this is a lot of work.. Port work on the heads should be minimal you need to know what you are doing Any internal modifications are a waste ot time untill the exhaust is free flowing,,because the exhaust chokes the engine The weld at the entrance MUST be smoothed out so it is all the same size ,, the stainless metal that flows to the rear must be removed it is a blocking force,, you have to get in to the runner and clean this up with a file .. the first port should also have the flow smoooooothed ..I get into the inside of the port and sand down the stainless steel that protrudes into the port .. The Y pipe needs to be cut open and the obstruction cut away it will take 20 hours to modify the exhaust system .. the stock manifolds with proper porting will make a big difference in the car Top quality ignition wires ,magnecore or granatelli, single electrode spark plugs "indexed" do not go cheap on the ignition wires set timing as close as you can get proper ground wires when you need a battery get a great one ,,when you need tires install taller ones An engine swap is not the 3 some with pam anderson & paris hilton many on here say it is..Avoid this unless you really want it..the pulling of the exhaust manifolds is a nite mare with the man with the ax chasing you (and catching you) but worth it.. the trueleo headers are the best option for increase performance if you married well or recently imported a large supply of a green leafy medicinal herb from a south american country or hit the lottery ,,Trueleo forum and dyno proven
Agree. The only beneficial K&N upgrade is the CRX intake with the filter placed in the wheel well. That said, I have a good friend who was pumping a turbocharged v8 using the stock Fiero intake. Think about that one for a sec. before you put out cash. I think he removed the water separator only.
We recommend using Rodneys mod to airbox for anyone using our intakes especially with our headers too. It's an easy way to get rid of the water seperator and his pricing very good. Just not worth the bother to do it yourself.
