im rebuilding my 2.8 this winter, im trying to figure out if i want to do a turbo or a supercharger. i just want to hear both sides... also ive been serching the internet but ive only found one turbo kit so far, anyone have any kits for either a supercharger or a turbo?
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03:27 PM
PFF
System Bot
Ace McCloud Member
Posts: 167 From: Marble Hill, Missouri, United States Registered: Jul 2007
2.8's may not be the "best" engine for a turbo or supercharger. I know of a few turbos (Miller-Woods) for the 2.8, but I havent heard of any superchargers for the 2.8. Good luck with the 2.8 rebuild..make it strong.
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03:36 PM
crytical point Member
Posts: 569 From: sanford FL USA Registered: Feb 2006
Faegol makes a supercharger and some one has made a M90 from a Tbird fit. Turbo's are not Free power they provide restriction to the exhaust and reduce engine life and increase the heat in a poorly vented fiero engine compartment.
I think he meant turbos do not produce parasitic drag like a supercharger does with the belt. You are utilizing exhaust air which was going to be dumped overboard anyway to produce horsepower.
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06:19 PM
TD37 Member
Posts: 746 From: Howards Grove, Wisconsin Registered: Jan 2004
When it comes to big power adders, you really have 4 choices. Roots supercharger, centrifugal supercharger, turbocharger, and nitrous. The best for less power adder hands down, is nitrous. You will get the biggest gain, for the least money and the least amount of modification. Nitrous has a terrible reputation from people that don't know how to use it. If it is setup properly and you have enough safety nets, you can have a long and happy relationship with nitrous. Even a stock motor can take SOME nitrous. In my opinion the next best is a tie between a centrifugal supercharger and a turbo. This is pretty easy to understand considering a centrifugal blower is basically a belt driven turbo. I'll break it down like this.
Turbo Adv. Less power loss per power gain (efficient) high output possibility cool BOV sound (even if it is the worst thing you could do for performance) can be mounted almost anywhere per application
Dis Adv. intricate exhaust and headers larger exhaust required BOV / wastegate plumbing intercooler plumbing lots of heat in an already toasty engine bay turbo lag exhaust maintenance (cracking from extreme heat cycles. You've seen the videos of glowing white exhaust on turbo cars.)
Centrifugal Blower Adv. turbo efficiency without the lag no exhaust restriction or heat build up more compact than roots blower blower wine!!!
Dis Adv. intercooler / wastegate plumbing definite mounting may not work for applications not as much maximum gain as a good turbo setup still pretty hot
Roots Blower Adv. sticking through the hood is always a crowd pleaser easy install, cut a hole, bolt on BLOWER WINE!!!
Dis Adv. robs power to make power low efficiency intercooling/aftercooling is tricky huge pulley off the crank say goodbye to the sleeper very hot
I've never really priced out a turbo setup, but blowers are usually $3000. In the same vein for $500 you can add 50 - 100 hp with a quick shot of nitrous and you can install it in a weekend. If I just wanted a little zip I would have to go with nitrous. I will put it on my SBC car eventually. My 2cents, hope this helps.
-Tim
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06:23 PM
bmwguru Member
Posts: 4692 From: Howell, NJ USA Registered: Sep 2006
2.8's may not be the "best" engine for a turbo or supercharger. I know of a few turbos (Miller-Woods) for the 2.8, but I havent heard of any superchargers for the 2.8. Good luck with the 2.8 rebuild..make it strong.
The 2.8 is an excellent engine for a turbo or supercharger. I've put a dozen turbos and s/c on BMW 2.8 liters. My wife's soon to be a VR6 Fiero, also a 2.8, is a great turbo candidate. I think the only 2.8 that isn't worth putting a turbo or supercharger on would be the GM engine....oh wait....I'm posting in a Fiero thread......dang......I mean....er.....uh..........oh....... nevermind me Dave
if you are mechanically inclined and have a good tig welder or even a mig welder with gas you can do a Turbo for less than $500.00 easily. USED tbird T3 turbo and weld everythign else together. Cracking on turbo exaust is from not building the thing right. you need slip joints and flexible joints.
After learning about them, a Turbo is actually quite easy. Easiest is a Centrifugal Supercharger. Hardest and absolutely most expensive is a roots blower.
If you get a good used turbo that is RIGHT for the car and what you want to do, that makes it cheap, but of you cant weld, or are afraid to learn then it's not cheap.
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08:29 PM
Dennis LaGrua Member
Posts: 15741 From: Hillsborough, NJ U.S.A. Registered: May 2000
On the 2.8. 3.1 and 3.4L family of V6 engines I would only turbocharge as there is not much room to mount a blower and also keep the A/C.. The turbo has the slight disadvantage of a small amount of lag while the power in the roots (positve displacement) blower is instanteous. However, we solved the problem on the turbo 3.4L by using an automatic with a 3000 RPM stall speed torque converter and 3:33:1 gearing. With this setup we can shoot out of the hole with boost already present which makes for a very exciting 0-60 time.... And Dave we do run Ross Forged Racing Pistons, Total Seal Rings, a Comp Cams turbo grind cam and kit, blueprinting, balacing and the rest. Point is that you can safely run a GM 60* V6 if it's built for the application. Have you sen what a turbo 3.4L can do in a Camaro in the 1/4 mile? Check out this link and the video: http://www.force-fed-fabrications.com/index2.htm you can see the dyno test in a 3.4L Camaro (337HP@ 397 ft lbs torque) and you can see the same car running the 1/4 mile in the 13's. It may not be an intercooled modified 3800SC or V8 but still not bad at all for the 60* V6.
------------------ 87GT 3.4 Turbo- 0-60 5.2 seconds 2006 3800SC Series III swap in progress Engine Controls, PCM goodies, re-programming & odd electronics stuff " I'M ON THE LOOSE WITHOUT THE JUICE "
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08:37 PM
craigsfiero2007 Member
Posts: 3979 From: Livermore, ME Registered: Aug 2007
Don't do that to yourself, I believe you'll get a brief efficiency increase at opening throttle. I've seen a leaf blower connected to a Honda 4 banger on the dyno and it moves serious air compared to that contraption on Ebay but it still didn't increase power enough to make one bother trying to use one on a car. Someone's trying to take your money, I'd put that thing in the same pile with the turbinator thingy that you put in your intake system to swirl your intake air to the tune of whatever mpg and hp increase they claim it will despite the local news story performed on several alleged power adders tested under organized conditions proving they were garbage and in nearly every test decreased power/mpg. I can't believe PepBoys is allowing it to be sold in their stores.
[This message has been edited by Joseph Upson (edited 09-04-2007).]
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08:57 PM
PFF
System Bot
Firefighter Member
Posts: 1407 From: Southold, New York, USA Registered: Nov 2004
I agree with J. Upson. ALL electric supercharger/turbos are snakeoil. They all are nothing more than a car heater motor painted nicely. I took my electric leaf blower and hooked it to a 2,500 watt power inverter just to see what would happen. Pretty much nothing - it ran at about 1/3 the rpms and had no power at all. So, electric anything is just a joke. As Dennis points out,-if you go the centrifugal supercharger route, you loose your A/C, but no matter what you do in the form of a kit, it will cost you $ 3,000. I think that Design 1 is the only turbo kit maker left that makes a setup for the 2.8. Save your pennies for a Northstar conversion. Ed
On the 2.8. 3.1 and 3.4L family of V6 engines I would only turbocharge as there is not much room to mount a blower and also keep the A/C.
Dennis raises an interesting point. The one supercharger kit for the V6 Fiero that I'm aware of requires you to lose your air conditioner, unless you can figure out how to successfully relocate its compressor somewhere else.
You'd have to be insane to toss your A/C in a daily driver for a blower, if not and you live in Florida you will be insane after the heat finishes with you. Turbos really don't require as much plumbing as some alledge, it depends on the positioning of the turbo, hanging off the manifold in a 4 cyl car is quite uncomplicated and attached to the crossover in a V6 the same. Turbo lag just isn't true anymore, technology has come a long way as well as fuel injection and the ability to combine high compression and boost in the same engine. The only down side to a turbo engine now is heat and you can wrap a good exhaust system to make that a moot point. More and more manufacturers are turning to turbos now than ever before it seems, and as far as mileage is concerned a properly sized turbo will pose little resistance to exhaust flow and some are actually designed to have the wastegate open during non boost conditions to help reduce exhaust flow interference.
If I ran a company that used trucks for hauling and medium duty work I would take a small turbocharged engine for my fleet and take advantage of the fuel economy of the small engine with the ability to put out big engine power only when necessary. That's the principle behind DOD in the GM engines, reducing power output closer to what is necessary to maintain cruising speed by shutting down half the cylinders. Without it you end up cruising at a horsepower level far in excess of what's needed and you have to feed that efficiency level with the proper amount of fuel eventhough you don't need it for the load the engine is driving.
On the 2.8. 3.1 and 3.4L family of V6 engines I would only turbocharge as there is not much room to mount a blower and also keep the A/C.. The turbo has the slight disadvantage of a small amount of lag while the power in the roots (positve displacement) blower is instanteous. However, we solved the problem on the turbo 3.4L by using an automatic with a 3000 RPM stall speed torque converter and 3:33:1 gearing. With this setup we can shoot out of the hole with boost already present which makes for a very exciting 0-60 time.... And Dave we do run Ross Forged Racing Pistons, Total Seal Rings, a Comp Cams turbo grind cam and kit, blueprinting, balacing and the rest. Point is that you can safely run a GM 60* V6 if it's built for the application. Have you sen what a turbo 3.4L can do in a Camaro in the 1/4 mile? Check out this link and the video: http://www.force-fed-fabrications.com/index2.htm you can see the dyno test in a 3.4L Camaro (337HP@ 397 ft lbs torque) and you can see the same car running the 1/4 mile in the 13's. It may not be an intercooled modified 3800SC or V8 but still not bad at all for the 60* V6.
I was just making a joke. I really didn't think you could make any power with the 2.8/3.4 turbo. Then again, I never took a ride in your car...yet. I guess if you look at the $$$ invested, most people would just drop in a 3800s/c for the same price. Dave
Originally posted by Firefighter: ...electric anything is just a joke. ...
This is not true, there are electric superchargers out there that work very VERY well. Problem is you need to carry with you about 8 deep cycle car batteries and you get 1 maybe 2 boosts from the batteries before you have to stop and recharge. They are made by putting a real turbo compressor onto a high power high RPM motor. they cost between $1600.00 and $3800.00 for a kit and are for strip racing only.
Contrary to the guys here that believe the 2.8 can't be boosted, it can, ANYTHING can be boosted. without building up the inside you can't go far, maybe to 175hp safely on a older tired engine. if you build up the inside you can go farther. if you want to sacrifice longevity you can go even farther. If you build it for a single run down a strip expecting it to explode, you can go insane.
What are the sacrifices you want to make? If you were expecting to a buy a kit, slap it on in 2 hours and go driving, it does not exist and will never exist all your options are lots of work, time, and money.
[This message has been edited by timgray (edited 09-05-2007).]
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08:13 AM
Ace McCloud Member
Posts: 167 From: Marble Hill, Missouri, United States Registered: Jul 2007
the kit is not the way to go $3K for prebent pipe and a turbo. "KIT" step one get a T3 from the junkyard rebuild it then get some exhaust and intake pipe and pipe bender at harbor freight is like $99 then weld up. These are not all of the steps but most of the basic ones there are lots of threads on here on how to make one yourself you would prolly save yourself $2500.
P.S. mass produced does not allways mean well engineered.
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09:24 AM
Will Member
Posts: 14275 From: Where you least expect me Registered: Jun 2000
Originally posted by TD37: In my opinion the next best is a tie between a centrifugal supercharger and a turbo. This is pretty easy to understand considering a centrifugal blower is basically a belt driven turbo. -Tim
I'll have to strenuously disagree with your assesment. A centrifugal blower is NOT a belt driven turbo. It is a belt driven centrifugal compressor. It only makes max boost at redline. A turbocharger will yield approximately the same peak power but with utterly destroy the centrifugal supercharger in mid range torque.
A magazine did a comparison among a roots blower kit, centrifugal blower kit and turbo kit on a built 302 (or was it 351?). The roots was at the bottom of the heap. The centrifugal just edged out the turbo for peak horsepower (about 600 IIRC), but the turbo made OVER ONE HUNDRED FIFTY more ft lbs at 3500-4000 RPM.
[This message has been edited by Will (edited 09-05-2007).]
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03:12 PM
ITwasntME159357 Member
Posts: 17 From: naperville, il Registered: Sep 2007
No a 3800sc blower will not work on a 60V6 without ALOT of work. Search I and others have beat it to death.
The centifugal may make more peak but as far as usable power it sucks ass. If you want to make cheap power for racing go nitrous, if you want to make cheap power all the time roots, if you want to make big power go turbo.
When looking at dyno charts look at the curve not the peak numbers. Peak numbers mean nothing.
[This message has been edited by goatnipples2002 (edited 09-05-2007).]
Call me an ol' fogey but I still like a belt drive double screw supercharger.
Put a big 'ol carb on top and a chrome air breather sticking up out of the hood and you have instant eye candy. You also have something that gives you some pretty respectable power without complication. Yes, you do have to know how to tune a carb, and no, you don't have to lose your A/C.
You can build up an intake that will take a roots blower though. All it takes is money.... lots and lots of money. Or knowing someone at a aluminum foundry and someone that can make a investment casting mold for you. Although you could weld one up I suppose.
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07:30 PM
Zac88GT Member
Posts: 1026 From: Victoria BC Registered: Nov 2004
Welding one up is a piece of cake. My friend hamish and i did this in high school for a 671 blower on our drag car. We made our own intake manifold from steel and booty fabbed a drive system using volvo and vw timing gears and belts.
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07:36 PM
ITwasntME159357 Member
Posts: 17 From: naperville, il Registered: Sep 2007
The 2.8 is an excellent engine for a turbo or supercharger. I've put a dozen turbos and s/c on BMW 2.8 liters. My wife's soon to be a VR6 Fiero, also a 2.8, is a great turbo candidate. I think the only 2.8 that isn't worth putting a turbo or supercharger on would be the GM engine....oh wait....I'm posting in a Fiero thread......dang......I mean....er.....uh..........oh....... nevermind me Dave
Ah but what about the new GM global 2.8? hehe that one would rock with direct injection and a turbo.
------------------ If you can't be good, be good at it.
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06:06 AM
crytical point Member
Posts: 569 From: sanford FL USA Registered: Feb 2006
Read about the engine in the SAAB Aero X and be suprised because that 2.8 with twin scroll turbos put 400hp 400tq to the wheels on ethanol and maybe 10psi.
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03:22 PM
GKDINC Member
Posts: 1813 From: East Tawas MI Registered: Dec 2001
JMO, but I have drivin a v-8sbc, a 3800SC motor, and a turbo installed v-6. If i wanted HP I would go the turbo route. Again, Just My Opinion, This and a dollar will get you a cup of coffee Good Luck Gary
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05:14 PM
Firefighter Member
Posts: 1407 From: Southold, New York, USA Registered: Nov 2004
I stand corrected. TimGray is right. There is an electric supercharger out there for between $ 2,500 and $ 3,500, and we have all seen it. But as Tim says, it takes 1.5 giggawatts of power to operate (like in the flux capacitor - Back to the Future). And if you have to carry around another 250 lbs. of batteries that need a charge after every boosted run, WTF it makes no sense at all. It's like putting your 250 lb. friend in the passenger seat and challenging someone to a 2 out of 3 drag race. You only have one shot with your fat passenger so you can't win even racing a Yugo; you only get one run. Years ago, I bought a Turbo kit from Dennis which was a KFG T/3 kit at the time. Here are the stats on my stock 2.8; engine has only 15,000 miles on it. At 8 lbs. of boost: Stock 10 degree BTC timing 0-60 in 6.5 to 6.8 secs. 199 hp Approx. 230 lbs. torque Increase air flow of 51 % MSD 6A ignition (of questionable value) Water / Alcohol Injection "Poor Man's Intercooler" Turbocharged hot intake air cooled by 53% as it enters the intake
[This message has been edited by Firefighter (edited 09-06-2007).]
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08:17 PM
ITwasntME159357 Member
Posts: 17 From: naperville, il Registered: Sep 2007
don't forget about a magnacharger. im sure if u put a scoop or something on top and find the best place for the intake that would be the best way to go. im not a big fan of turbos. especially since when i hear turbo i think rice burner. get creative and think of unlikely places to put things. and from what i hear u can have a superchager and a turbo that are the same size but the supercharger will put out more power than the turbo since it will run cooler. i know thats the point of an intercooler but just saying what i know. i was actually looking into this also. i just rebuilt my engine (2.8 bored to about 3.0) with forged pistons and all that good stuff and was lnterested in putting a superchager on their. from all the videos iv'e seen (which im sure are 3800 SC's) they looked pretty quick. then got talked into dumping that idea and saving the 3000 dollars that i would have spent to go to a 69 camaro that im gonna use for racing while keeping my fiero as my everyday driver.
You have it way backwards a turbo is the key to REAL power. Turbos are way more efficient than superchargers. Blowers are easier to install most of the time and most times have less components in their system. Whether you feel they are rice or not turbos out perform all other forms of boost. The only thing that MIGHT compare is nitrous. No matter what company names their charger whatever you still only have a centrifugal, roots, twin screw or turbo.
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11:48 PM
Sep 7th, 2007
fieroX Member
Posts: 5234 From: wichita, Ks Registered: Oct 2001
Originally posted by fieroX: Care to explain how a blow off valve reduces performance?
I always was under the impression that a blow off valve is wasting a shot of air that could be used to keep the turbo spooled between shifts, like a recirculating valve. It may not hurt performance, but it may help.
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01:42 AM
Firefighter Member
Posts: 1407 From: Southold, New York, USA Registered: Nov 2004
Guys, Goatnipples2002 is correct. Unless you already have a 3800 Series II SC which was put together at the factory, a turbo is the way to go. Also, it is not a rice burner idea. The first turbo car was built in the United States in the 1960's by Oldsmobile (I believe). And for you 5 speed guys, a 2.8 Fiero 5 speed with turbo is slower than a 2.8 automatic, with the same turbocharger. I do suppose however that a Vortec belt driven supercharger is easier to install than even a turbo kit. But you have to give up your A/C, and that's no OK for us non Alaska and Canada guys.
[This message has been edited by Firefighter (edited 09-07-2007).]
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10:11 AM
Will Member
Posts: 14275 From: Where you least expect me Registered: Jun 2000
The purpose of a BOV is to keep the turbo spooled. It dumps excess flow when the throttle is closed to keep turbo RPM from dropping as quickly as it would without the BOV
Everything I've read says the BOV is a good thing as Will said. The part I do not understand is the use of Bypass valves which are nothing more than a BOV with the air routed back into the incoming air instead of to the atmosphere. It would seem that adding this hot compressed air to the incoming cool air would not be good.
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10:35 AM
fierosound Member
Posts: 15217 From: Calgary, Canada Registered: Nov 1999
I do suppose however that a Vortec belt driven supercharger is easier to install than even a turbo kit. But you have to give up your A/C, and that's not OK for us non Alaska and Canada guys.
My car never had A/C. If it did, I'd have taken another route for boosting the engine But don't kid yourselves, the centrifugal S/C does make more power than you'd expect. If it didn't, nobody would be shelling out $$$ for the aftermarket installs on Vettes etc.
------------------ 3.4L S/C 87 GT www.fierosound.com 2002/2003/2004 World of Wheels Winner & Multiple IASCA Stereo Award Winner
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10:55 AM
Zac88GT Member
Posts: 1026 From: Victoria BC Registered: Nov 2004
Everything I've read says the BOV is a good thing as Will said. The part I do not understand is the use of Bypass valves which are nothing more than a BOV with the air routed back into the incoming air instead of to the atmosphere. It would seem that adding this hot compressed air to the incoming cool air would not be good.
I think the idea behind the bypass valve is that the expelled air will be directed back at the compressor wheel to try and not lose any rpm that you would just venting it. I don't think that mass airflow cars like to be vented to atmosphere because you're losing metered air. I know some talon guys and they all keep there BOV bypassing because it doesn't run right if you vent it. One guy vents is but he's running some weird vain pressure control thing.
Originally posted by fierosound: My car never had A/C. If it did, I'd have taken another route for boosting the engine But don't kid yourselves, the centrifugal S/C does make more power than you'd expect. If it didn't, nobody would be shelling out $$$ for the aftermarket installs on Vettes etc.
No matter what they are on the bottom of the list for their USABLE power band. People pump out money for them cause they just don't know and they think all SCs are the same. They are the easiest to install as well. Not knocking anybody's choice, they just don't perform as well as other forms of boost for the racing I want to do. They produce sweet PEAK numbers, but we all know peak means nothing.
quote
Originally posted by Will: The purpose of a BOV is to keep the turbo spooled. It dumps excess flow when the throttle is closed to keep turbo RPM from dropping as quickly as it would without the BOV
The purpose of the BOV is to let that air out so it doesn't damage the turbo by making it change directions. If you didn't have a BOV the air would be forced back into the turbo fighting the impeller. If the vented air is used as a recirculating valve then the rpms on the turbo/motor will stay or slightly raise. Where as in a BOV shooting into the atmosphere, when you shift the rpms will drop.
hehe that one would rock with direct injection and a turbo.
