I had some more questions, I've got my hands on a 3.1L V6 from an Oldsmobile that I know to be good (ran perfectly before removal). But I was wondering, as the stock 2.8L with the turbo that a previous owner had installed broke due to a piston breaking, what do I need to turbo it right? Should just forged pistons roughly cover the job or do I need a whole lot more to prepare the engine? And also, what would be a good place to get forged pistons for a 3.1L?
Thanks again in advance,
Ren
Edit: Or does anyone reckon I could use the stock internals if I just keep a modest level of boost?
[This message has been edited by Renier (edited 03-11-2015).]
I just want to make sure you know how to run the SEARCH function, because there is a lot of information in there. Make sure you set your drop-down menu to include the ENTIRE FORUM + ARCHIVES and threads will come up from 3 and more years ago. The 3.1 used to be more popular than it is now.
[This message has been edited by Gall757 (edited 03-11-2015).]
AFAIK 3.1's aren't popular at all (save for the McLaren ones)! But I'm asking for myself, not for those guys 3 years or longer ago, I'll see if I can dig something up that I couldn't dig up before however.
[This message has been edited by Renier (edited 03-11-2015).]
Two good things to add that will help the engine handle boost are an intercooler and a water injection system. Both are easy to add, inexpensive, will allow you to use greater boost and will help reduce the risk of engine damage.
Two good things to add that will help the engine handle boost are an intercooler and a water injection system. Both are easy to add, inexpensive, will allow you to use greater boost and will help reduce the risk of engine damage.
Thanks! I've always wondered where to mount the intercooler though? Maybe I could utilize the large way bigger than stock airscoops on the sides of my Fiero, run some sort of tubing behind them to the intercooler.
So if I can put the intercooler in the engine bay, or if need be in the boot then I could possibly have airflow from those with tubes go into the intercooler, right? Or just one of them, I guess.
If you keep boost reasonable , 8 lbs or less I would go with the stock pistons. You must address the compression of the engine and possibly reduce the piston height. Head gasket strenght can be a problem (blow out). The advice above is good . You should read, read, read. You are entereing a very technical area, but one with lots of information.
Actually, the picture I linked is the official Pontiac turbo Fiero prototype. The intercooler is actually the mid-section of the spoiler.
Woah, that's pretty cool actually
And as for the other stuff, you're suggesting that I could have the stock pistons machined to drop compression even lower? These American engines already have quite low compression compared to cars here, but then again our fuel has a higher octane count and hence won't cause engine knock quite as easily, due to this I thought I wouldn't have to do anything with the compression just possibly the pistons to handle the extra power better. I could of course be direly mistaking, for this is the very first time I'm doing something like this and could surely use any help from people with experience.
Thanks either way!
PS: I don't like the idea of having an intercooler in my spoiler, but if that's the way to go then that's the way to go, I thought it might also get enough airflow right about where the stock muffler would normally sit though? I've read about someone else having it there and not seeming to have any trouble getting airflow.
[This message has been edited by Renier (edited 03-13-2015).]
The tough thing with the Fiero is getting the intercooler into a position where you can get maximum cool air flow through it, while keeping it away from excess engine or exhaust manifold heat, whilst keeping the air intake lines as short as possible. There are a lot of trade offs and compromises. Definitely need some creativity...every set up is somewhat unique. As previously mentioned, start by reading/researching as much as possible so you can get a good understanding of the science behind turbos and related equipment. You'll find water injection is a little easier to set up.
you said your engine is from an Oldsmobile so I am guessing its the aluminum head version. You don't need to lower compression at all. Its less than 9:1. You should be able to run 7 psi on your engine no problem and forgo the intercooler with that little boost. you don't need forged pistons either. stock will work just fine unless you are going for 400 hp. I guess we need to ask what your powergoals are
Use an air to water setup for your intercooler .And use water meth injection .Your compression is fine the way it is .Forged pistons are needed to go to higher boost levels , most stock GM cast pistons have weak ring lands .You will need bigger injectors even running low boost pressures like 8 PSI .You can also run an aftermarket mechanical fuel pressure controller , they work really well for the type of old fashioned engine controls on a 3.1 .You can find a lot of this info on my thread in the construction zone "ecotec swap "have fun hope this helps .
you said your engine is from an Oldsmobile so I am guessing its the aluminum head version. You don't need to lower compression at all. Its less than 9:1. You should be able to run 7 psi on your engine no problem and forgo the intercooler with that little boost. you don't need forged pistons either. stock will work just fine unless you are going for 400 hp. I guess we need to ask what your powergoals are
Thanks for the advice guys! As for my powergoals, I'd say anything over 200 is a very welcome extra, but hitting 200hp would be great with the stock internals.
quote
Originally posted by wftb:
Use an air to water setup for your intercooler .And use water meth injection .Your compression is fine the way it is .Forged pistons are needed to go to higher boost levels , most stock GM cast pistons have weak ring lands .You will need bigger injectors even running low boost pressures like 8 PSI .You can also run an aftermarket mechanical fuel pressure controller , they work really well for the type of old fashioned engine controls on a 3.1 .You can find a lot of this info on my thread in the construction zone "ecotec swap "have fun hope this helps .
Many thanks! I'll look into water injection, seems rather unpopular here but there certainly are kits available. I'll also look for bigger injectors and try to find out exactly what you mean with the air to water setup for the intercooler.
[This message has been edited by Renier (edited 03-15-2015).]
check out frozenboost.com a great place for turbo parts and air to water intercooling .Watermeth injection is very effective for turbos , not so great for a supercharged car .It tends to be hard on supercharger lobes , not something you worry about with a turbo .
My bad, my bad, I asked the previous owner some questions about the engine and it's actually from a 1991 N/A Pontiac Grand Prix, which he still drove around in one year ago. All of the gaskets and such have been replaced actually, but due to having 3800 series V6's in most of his cars now he no longer has any use for the engine and I can have it due to me helping him out.
[This message has been edited by Renier (edited 03-20-2015).]
Originally posted by Renier: My bad, my bad, I asked the previous owner some questions about the engine and it's actually from a 1991 N/A Pontiac Grand Prix, which he still drove around in one year ago. All of the gaskets and such have been replaced actually, but due to having 3800 series V6's in most of his cars now he no longer has any use for the engine and I can have it due to me helping him out.
My personal opinion is that if your goal is 200hp, then I would just rebuild this motor to a 3.4 and do intake and head porting (since GEN2 head flow no better than Fiero heads) and order a performance cam from WOT-Tech. Don't tackle the double complexity of swap+turbo at the same time. If you aren't happy with the 3.4 build you could still turbo later.
My personal opinion is that if your goal is 200hp, then I would just rebuild this motor to a 3.4 and do intake and head porting (since GEN2 head flow no better than Fiero heads) and order a performance cam from WOT-Tech. Don't tackle the double complexity of swap+turbo at the same time. If you aren't happy with the 3.4 build you could still turbo later.
His 3.1 can't be taken out to a 3.4 as it would require too much of an overbore. you are wrong about gen 2 heads. they flow way better than fiero heads stock for stock especially at low lifts because of the canted valve design. where do you come up with this false claim? don't tell me you are going to quote GMs horsepower figures as proof. post real flow charts stock for stock.
if I was the op, I would find a way to put the turbo kit that was on his iron head motor onto his aluminum head motor. slot the exhaust manifold holes for the different bolt spacing on the aluminum head, bolt the turbo kit on, and make 200 hp on 7 psi. no water injection needed.
His 3.1 can't be taken out to a 3.4 as it would require too much of an overbore. you are wrong about gen 2 heads. they flow way better than fiero heads stock for stock especially at low lifts because of the canted valve design. where do you come up with this false claim? don't tell me you are going to quote GMs horsepower figures as proof. post real flow charts stock for stock.
if I was the op, I would find a way to put the turbo kit that was on his iron head motor onto his aluminum head motor. slot the exhaust manifold holes for the different bolt spacing on the aluminum head, bolt the turbo kit on, and make 200 hp on 7 psi. no water injection needed.
Many thanks for the information! I can gain a lot too by having custom exhaust manifolds, right? As I take it there probably wouldn't be any premanufactured aftermarket manifolds available for such an application.
the easiest route for you to take would be to modify your existing iron head exhaust manifolds for the bolt pattern of the aluminum heads. that way your current turbo kit bolts on like before. second is finding a set of exhaust manifolds from a turbo grand prix. its sort of like your lho but turbo from the factory. you would prob have to build your own custom y pipe for the turbo. third is building your own headers and your new y pipe to the turbo. that would be the most labor and cost. what turbo kit do you have or can you post pics or a link?
Originally posted by bigformula: His 3.1 can't be taken out to a 3.4 as it would require too much of an overbore. you are wrong about gen 2 heads. they flow way better than fiero heads stock for stock especially at low lifts because of the canted valve design. where do you come up with this false claim? don't tell me you are going to quote GMs horsepower figures as proof. post real flow charts stock for stock.
if I was the op, I would find a way to put the turbo kit that was on his iron head motor onto his aluminum head motor. slot the exhaust manifold holes for the different bolt spacing on the aluminum head, bolt the turbo kit on, and make 200 hp on 7 psi. no water injection needed.
Why would a 91 3.1L block be any different than a 3.4L block? The wall thickness/cyclinder separation hasn't changed and the outer walls are always thicker than the inter-cylinder walls. Plenty of people have bored 2.8 and 3.1 blocks to 3.62" Why are you comparing iron heads to aluminum heads? I told him to rebuild the 3.1MPFI motor into a 3.4L version and to port THOSE heads as part of the rebuild of THAT motor as a simpler job that could match the performance of adding a turbo with mild boost.
My Ferrari kit had a Z-24 3.1. It had the Design One turbo kit and ran the 2.8 intake. It was built for me by a guy I knew in a Nascar teams engine shop back then during off season. I normally ran it with about 8 pnds boost and no intercooler. At that time it was fast as hell. I never had any problems with it for 100,000 miles till it wore out the turbo. It was VERY fun to drive. I really dont know much of what all was put in it. I do know he 'O' ringed the cylinders along with the head gasket.
Why would a 91 3.1L block be any different than a 3.4L block? The wall thickness/cyclinder separation hasn't changed and the outer walls are always thicker than the inter-cylinder walls. Plenty of people have bored 2.8 and 3.1 blocks to 3.62" Why are you comparing iron heads to aluminum heads? I told him to rebuild the 3.1MPFI motor into a 3.4L version and to port THOSE heads as part of the rebuild of THAT motor as a simpler job that could match the performance of adding a turbo with mild boost.
/fail
Are you serious? it is totally different. plenty of people have bored the 2.8 block with a 3.5 inch bore to a 3.62 bore? so a .120 over bore? name one person who has done that. just one name. i am not comparing iron to aluminum. you did. you said iron flows as well as gen 2's gen 2s are aluminum. the iron heads don't flow anywhere near gen2 stock for stock. I am asking you to post flow sheets proving your claim that gen2s don't flow any better than fiero heads. you said it. now I am asking for you to prove it.
My Ferrari kit had a Z-24 3.1. It had the Design One turbo kit and ran the 2.8 intake. It was built for me by a guy I knew in a Nascar teams engine shop back then during off season. I normally ran it with about 8 pnds boost and no intercooler. At that time it was fast as hell. I never had any problems with it for 100,000 miles till it wore out the turbo. It was VERY fun to drive. I really dont know much of what all was put in it. I do know he 'O' ringed the cylinders along with the head gasket.
Are you serious? it is totally different. plenty of people have bored the 2.8 block with a 3.5 inch bore to a 3.62 bore? so a .120 over bore? name one person who has done that. just one name. i am not comparing iron to aluminum. you did. you said iron flows as well as gen 2's gen 2s are aluminum. the iron heads don't flow anywhere near gen2 stock for stock. I am asking you to post flow sheets proving your claim that gen2s don't flow any better than fiero heads. you said it. now I am asking for you to prove it.
Are you serious? Where did I mention iron heads? I said he should rebuild his 3.1 into a 3.4...and port the GEN2 heads as part of the rebuild of that motor...and to skip turboing it for now. I don't give a crap what you believe, search the forum and also ARI sold engines that were bored to 3.4 and I just had a 3100 block bored to 3.4 liters for my up coming Formula swap.
You have issues. You're clearly bringing up things from another thread. Judging by when you registered and your post count, you must be a previously banned troll.
[This message has been edited by lou_dias (edited 03-20-2015).]
Woah, thanks for the information though, guys. I'll see if there's a way to have my engine made into a 3.4 but where could I get good pistons for that?
And damn, Roger Garrison, that's really cool!
As for the Turbo, the pictures I have aren't very clear but it's an IHI RHB5 turbo which is said to be a good reliable turbo for up to 10lbs of boost but worthless for more. Well, I guess that's perfect actually since I'll be wanting to run relatively low boost anyways.
What wftb said up there is spot on - air:water intercooler and some sort of water or meth injection. Really, for low boost you only need one or the other. 8psi will not generate a lot of heat, and 9:1 it reasonably low compression. Personally, I would start out with an inexpensive water injection kit and see if you still need the intercooler. Any place that tunes Saab, Volvo, or turbo Audis will be able to help you with a kit or the parts.
then I would just rebuild this motor to a 3.4 and do intake and head porting (since GEN2 head flow no better than Fiero heads)
Tell me I am wrong and that fiero heads aren't iron heads. you mentioned iron heads when you said fiero heads. now I am going to ask again. provide proof that fiero heads flow "no better" then gen 2 aluminum heads stock for stock. its a simple request which I am sure you have the data for since you made that statement. so I guess you are the one person that has bored a 3100 block .120 over. So how much did you pay for the sonic testing of the bore walls? how thick are they? just how much was your block affected by core shift?
As for the Turbo, the pictures I have aren't very clear but it's an IHI RHB5 turbo which is said to be a good reliable turbo for up to 10lbs of boost but worthless for more. Well, I guess that's perfect actually since I'll be wanting to run relatively low boost anyways.
glad to help. the IHI turbo is small. its only good for about 230 hp tops. just get .030 over pistons for your 3.1 that will make it a 3.2 thin cylinder walls can crack when under boost if machined too thin
What wftb said up there is spot on - air:water intercooler and some sort of water or meth injection. Really, for low boost you only need one or the other. 8psi will not generate a lot of heat, and 9:1 it reasonably low compression. Personally, I would start out with an inexpensive water injection kit and see if you still need the intercooler. Any place that tunes Saab, Volvo, or turbo Audis will be able to help you with a kit or the parts.
Thanks, man, I actually found a company in the Netherlands that sells watermeth injection kits, for about 350 euro I think it was for a solid kit. Would save a lot if it'd be enough instead of also needing an intercooler. Guess I should do that and just keep a very close eye on the engine temperatures.
As for rebuilding the motor, that'd be a complete waste probably, since the engine is in very good condition and there's still a lot of power left in the engine so I wouldn't want to touch for it's not only expensive but also a waste pretty much. Technically it could always be rebuild later on, in let's say a year or two or more.
I had some more questions, I've got my hands on a 3.1L V6 from an Oldsmobile that I know to be good (ran perfectly before removal). But I was wondering, as the stock 2.8L with the turbo that a previous owner had installed broke due to a piston breaking, what do I need to turbo it right? Should just forged pistons roughly cover the job or do I need a whole lot more to prepare the engine? And also, what would be a good place to get forged pistons for a 3.1L?
Thanks again in advance,
Ren
Edit: Or does anyone reckon I could use the stock internals if I just keep a modest level of boost?
The pistons in the stock 2.8L are inferior to those found in the 3.1L and up aluminum head motors. The 2.8L pistons are cast, the 3.1L pistons are hypereutectic and designed stronger structurally. I broke a ring land on one of the old 2.8L pistons under boost although it took a while. All I ever managed to do to the later design pistons particularly those from the 3.4L was chip them after severe spark knock and they are the same as those found in the aluminum head motors minus the considerable dish to lower compression.
In the absence of excessive spark knock you should be able to run 15 psi without any trouble on the stock 3.1 pistons but you'll be very happy with 7-10 psi. Do not lower your compression ratio unless you intend to run double digit boost on less than premium fuel, otherwise the stock compression ratio is fine, let the lower compression for boost doctrine die with the last year carburetors were placed on cars.
Water to air intercoolers work exceptionally well in the Fiero and so does water meth injection. Having run both setups I can tell you for your setup you only need to pick one, you don't need both, I do because I run high boost with high compression.
Do not adapt your old 2.8L turbo manifolds to the aluminum heads because the ports do not match although it will work, you don't want to obstruct exhaust flow coming out of the ports. If 200hp is all you're aiming for you really don't need to bother building a 3.4L since the turbo Grand Prix 3.1L was rated at ~205 hp. Install the proper size T3 turbo and you should be able to get more than that as the T25 on the Grand Prix actually choked it.
If they fit, because I have no idea, with the cradle and all. I do realize that the rest of the exhaust will have to be modified, but it will have to be anyways I think.
Otherwise there's always these, for the Grand Prix 3.1 which seem pretty nice and aren't cheap but I'd say affordable, or worth it would be the best way to describe it I think:
Loaded the engine into a horse trailer today, will be unloading it at my own workplace (it's not much, just a small portion of a warehouse, but hey it's certainly something at least) and doing some things to it before finally putting it under the Fiero. There's like a gasket or two that needs to be replaced, nothing much or out of the ordinary really, and I want to clean it thoroughly first of all.
[This message has been edited by Renier (edited 03-21-2015).]
neither of those headers systems will work. you said you have a turbo setup. those headers are for n/a applications. you said you already have the turbo kit. use what you have. I already said you can slot the iron head exhaust manifolds to fit the aluminum head bolt pattern. there will be no restrictions if done correctly as the port spacing and shape are the same on gen2 heads as the fiero heads. post pics of the engine you picked up so we can all see what you actually have to work with. and once again, stay away from water injection. its not needed for only 200hp
neither of those headers systems will work. you said you have a turbo setup. those headers are for n/a applications. you said you already have the turbo kit. use what you have. I already said you can slot the iron head exhaust manifolds to fit the aluminum head bolt pattern. there will be no restrictions if done correctly as the port spacing and shape are the same on gen2 heads as the fiero heads. post pics of the engine you picked up so we can all see what you actually have to work with. and once again, stay away from water injection. its not needed for only 200hp
What about using water injection instead of an intercooler though? Or would it be less effective?
don't use water injection at all. its not needed for 200hp. based on what you are saying you have an old IRM/design one turbo kit since you said you have the rhb5 turbo. that kit doesn't come with an intercooler and even though it might help a bit to keep intake temps down, its not necessary for a goal of 200 hp. you can do that on 7 psi with your 3.1. if you insist on fitting an intercooler in there, then find a used mr2 stock turbo intercooler. they are cheap and you can find a place to mount it with little problem as it is small.
[This message has been edited by bigformula (edited 03-21-2015).]
Alright, cool, guess I should look for a stock intercooler from a car off the junkyard or from someone who upgraded theirs or something, or an otherwise not too expensive intercooler setup. But what's the real difference between good headers and turbo manifolds? Other than the bolting pattern for the turbo on the end? Which I think would be a lot easier and better to weld onto headers than to weld an entire set of turbo manifolds for example.
Alright, cool, guess I should look for a stock intercooler from a car off the junkyard or from someone who upgraded theirs or something, or an otherwise not too expensive intercooler setup. But what's the real difference between good headers and turbo manifolds? Other than the bolting pattern for the turbo on the end? Which I think would be a lot easier and better to weld onto headers than to weld an entire set of turbo manifolds for example.
An air to air intercooler will be a waste of your time unless you accommodate some kind of extraordinary arrangement that will expose it to enough air to overcome the loss of efficiency to the restriction that it poses and I don't see that happening if you start with an intercooler that was designed for use on a much smaller displacement engine, I've tried it several times, it's near impossible to arrange it in the rear of the car in a manner that will allow sufficient air flow and laying it flat and putting an air dam behind it in the air stream beneath the car is not going to cut it.
For every 10 deg drop in intake air temp you can expect ~1% increase in performance output. It is true that you generally do not need intercooling at upwards of about 10 psi, but it is a difference you can feel having had the heat exchanger from my air water system ripped from my car after running over a deer. Further more it's subject to the turbo choice and how much heat it adds to the intake charge. Turbos that are under sized for the engine choice will add more heat so you are likely to experience an even greater performance loss due to inefficiency.
If you do not have spark knock sensing, some kind of intercooling is a wise idea.
Headers are nice but at your boost level a good low restrictive free flowing log style system is best. The more volume added to the exhaust before the turbo and the more heat lost from the headers due to the individual tubes, the more likely you are to have turbo lag. Wrapping the headers behind a turbo adds another problem, warping and cracks from the much greater heat intensity that will result. If you must, build a header system using schedule 40 weld elbows I believe it is.
[This message has been edited by Joseph Upson (edited 03-22-2015).]
Alright, cool, guess I should look for a stock intercooler from a car off the junkyard or from someone who upgraded theirs or something, or an otherwise not too expensive intercooler setup. But what's the real difference between good headers and turbo manifolds? Other than the bolting pattern for the turbo on the end? Which I think would be a lot easier and better to weld onto headers than to weld an entire set of turbo manifolds for example.
we really need more info on your turbo setup. you already have the turbo setup correct? without details we can only guess whats best for you. provide more info about your existing turbo setup, and how it is routed. post pics please. if you can't do this then we can't really help you.
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