tchernobog

I'm currently driving a '91 RS, 3.1 liter 6 cylinder. I had pretty much had my sights set on saving up the whole year, I'm a college student, and selling the car for a nice down payment on a different car. Unfortunately, I got a crazy itch tonight, and figured I'd ask about turbo charging the 3.1. By next summer, I'll have 5-6 thousand to play around with, so pretty much my plan is to buy a junker DD, and keep my car to learn how to build a turbo setup. Of course, this came after a stealership told me they'd offer me $500 for my car as a trade in, which is barely worth it.

On to other stuff. I have zero experience with forced induction. However, I have completely stripped down and rebuilt 5 engines with friends, including my own, so I am, by no means, mechanically stupid or inexperienced. I have friends who've built/worked on DSM's, so I've got help with FI available.

I absolutely love my car, I bought it non-running, and have pretty much learned engines from it, and I'd really hate to see it go, because I love the way it drives, and I know it inside and out. So, I can buy a DD for $2-2500, and spend the rest on a turbo setup. I'd be doing the work myself/with friends, outside of tuning. Would it be possible to build a reliable turbo setup for $2500-3000? Is the 3.1 even a good platform to turbo? If it is, are there any good write ups specifically for the 3.1? I read up on tech articles a lot, and I've got general knowledge as to how turbochargers work and the like, but it'd be a lot easier with a guide specific to the 3.1.

Thanks for any help in advance guys, help me give the million GT mustangs around me something to cry about.

grover85

Depending on your power goals I don't think you can go wrong when turbocharging something. There are a few V6 turbo guys that will be able to chime in on this subject.

tchernobog

I don't want huge amounts of power, maybe shooting for 300 whp, which I'm hoping is an achievable number for $2500-3000 with me doing all the work.

tchernobog

I'm not sure what made me decide to not check the v6 forums haha. I found a walkthrough, but if anyone wants to chime in still, that'd be great.

project89

a t61 with some ported heads and a 260 cam will put u above 300hp with around 11 psi

my current motor is making just a tad over 300 @ 6psi with a smaller t4 turbo (51mm vs 61 mm turbo)

depending on how much u can do urself plan to spend around 1000 to say 2000 depending on some of the parts u opt for i.e fuel management and things like that


edit just saw u mentioned whp to hit 300 whp expect to have to run about 16 psi with a very good port job on the heads an intake,if u have the money i would suggest doing a aluminum head swap,they flow alot better then the stock iron heads,u can make the power with the iron heads its just alot harder and u gota know what ur doing when it comes to porting them.

example guys with 3.4L short blocks with 11.0-1 cr with the 3500 aluminum heads are making 300hp na with large cams
my motor is a 3.1L 8.5-1 with iron heads that have been massively ported with a semi decent cam making that on 6psi of boost

one guys here is planning the 3.4/3500 build with 11.5-1 cr shooting for 300hp na and plans to boost the motor after,personally i think he wont make it over 5 psi before the thing detonates itself to death,but u never know

so if u got time watch the 2 builds see how they go and pick which one suits ur needs and ability to do.

tchernobog

I feel like I'm capable of doing most of it myself, the only thing I don't have the tools for is welding. My motor has 145k miles on it, I'd like to keep it at a lower psi, since this is just a tinkering car, how much would be safe on a stock bottom end/rods etc.? I've heard 5-9 psi is pretty much the limit for a stock bottom end.

If 300hp will be that much work, I'll shoot much lower. I'm really not looking for big numbers or anything, I really want to build this kit to learn how, more than make power.

project89

just a tad shy of 200k miles saw daily abuse of 18+ psi stock bottom end



ran till the day i pulled it to install my new motor,only thing wrong with it was when i did an oil change i started the car before i put oil in it so i kinda hurt the bearings,(low oil presure) but i still beat the piss out of it for another 5-6 months

there is no safe limit so to say,boost dosent kill the engine,detonation does,now granted it will take more detonation abuse at 7 psi then it will at 15 psi,but if u tune it right it wont detonate

project89

i see u just edit ur posts 300hp @ the crank is good enough to get u into the 13's, thats a good 4-5 seconds faster then stock with not to much work. 300 crank gets u about 250 or so to the tires.

heres a shot of an almost full pass on mine 6psi of boost had the girl i was teaching how to drive luanched the car or stayed int he throttle at the top end car would have gone 13's and the car weighed in at just over 3,300 pounds



http://www.fquick.com/videos/tunning...__2_6_psi/6194

some cleaned up mild ported heads, a 260 cam, t61 turbo and a around 11 psi will put u there

Z28ricer

And yet a little 2 liter 4 banger, with a small T25 turbo will go 8.33 in the 1/8th (about a high 12) without the porting, without a cam upgrade, and with a smaller turbo. Go figure...

firstfirebird

Yes, it's worth it

tchernobog

Well...I live within walking distance of my job, so I think I may forgo the cheap beater DD, and do a full build, forged internals and such, and just run low boost and have it as my DD.

And, of course, turn it up when i want to have fun. A fully built engine on low boost should be reliable, I'd think.

bl85c

Like firstfirebird and I keep saying the stock iron v6 heads are crap. You can go all out with proffesional porting just to get them flowing on par with stock 3500 heads.

Do yourself a favor and start with aluminum heads. The rods are factory forgings, the 3500 crank is forged (just needs the rod dowels turned down to fit) and there's forged pistons out there already.

tchernobog

The 3.1 rods are forged? Or are the 3500 rods forged?

bl85c

All 60* v6 rods are forged from the factory.

tchernobog

Well then, that saves a considerable amount of time/money.

firstfirebird

The rods are forged, but the rod bolts like to stretch. I used all stock fasteners in the 3.4/3500 but the 3.1/3400 is getting the best of the best. I hoping to land this deal on a rolling T/A and it will be getting stripped and caged for racing

__________________

daverr

No its not worth it.

dump the v6 and get v8. its a better return on the money.

eeeeeefirebird

i think you should buy a DD for 500 and turbo a 350. or turbo+nitrous the 3.1

GrayTA

My thoughts would be for the money going with a simple NA 350 would get you similar power gains without the on/off power of a turbo. Less moving parts to break and less work going into it.

Now if you just want to build the turbo setup thats another matter. I would still consider getting the 3.8 V6 as that yields a lot more displacement and therefore even larger power gains.

Just my .02


PDG

project89

the abilty to only use the added power when u want is the great part about a turbo setup,if u drive like a human, u get ur good gas milage,hell u will actually see an improvment in gas mileage to start,then the power is there when u want it.

eeeeeefirebird

bump for the 3.8, its a great engine.

83 Crossfire TA

You know, the messed up thing is that you’re getting a fairly mediocre response, but as far as “I want to turbo my shit” posts, you’ve made one of the more realistic posts that I’ve seen here on the board.

Is it worth it? Only you can really answer that… If I had a nice V6 car I would do it in a second. The power of a V8, a couple of hundred pounds lighter, better weight distribution, in theory you should be still be able to knock down MPGs in the 30’s on the highway while being able to run with all but the fastest cars out there and if you want to set it up for handling outhandle most of us V8 guys (who will outhandle a lot of the best cars out there on the road with the right setup).

Power, donno, what does it make NA? if you can get 15psig tuned correctly, figure you’ll be making about 2x that. I know that there are a few 60* V6 guys out there well into the 500hp range. Lets say you go fairly mild and are around 300hp. Setup right that should get you deep into the 12’s (my supposed 305hp 97 WS6 TA runs 13.006@107 at almost 4100lbs. you should easily be 800-1000lbs lighter). The stock 3.8 turbo buick setup used heads that are probably similar if not worse than t he 60* v6 heads, and in factory tune they were mid 13 second cars that again were heavier than your camaro…. Actually, if you’re looking for a mild setup that might be a good place to source a turbo from.

The only thing that I saw here that is a real problem is the lack of welding ability, but that can be worked around. You realistically have enough budget there to pay someone that knows what they’re doing, and you can fit up what you need and borrow a welder (or even grab the $1xx 90amp HF welder) and tack it together or leave index marks/tape thigns together for someone else to weld it up right. I do this kind of stuff for my brother all the time.

__________________
Mark
aka: Silverback, WS6 TA, JYDog, 83 Crossfire TA, mpikas, mmp...

firstfirebird

I thought it was worth it. Even turbo'ing the junk iron heads made it a fun car.

I wasn't trying to give a medocre response, but trying to state a fact. yes it was worth it.


N/A the 3.1 puts about 100hp to the wheels. Now, though, you use some newer aluminum heads (providing you get a grasp on tuning) the heart shaped chambers and canted valves really wakes up these little motors. In fact a member here who never posts on the V6 board took his 2.8 S10 and ran it with ~12:1 compression and says he could hardly believe it was a V6, never mind a 2.8. *But* we are talkking about an experienced tuner.

Another member has a 2004 3500 from a Malibu in his car and dynoed over 270whp with modifications like cam and porting, naturally aspirated.

The 60* V6 with iron heads weighs ~400lbs, i don't think we have that much weight savings over a V8, although, with aluminum heads from a FWD car we can be real close to 300. I just shipped an almost fully dressed roller FWD block to Canada (minus alt, A/C, and P/S pumps) and it was almost 320lbs on the button. You have to remember just as many V6's came with all the options as a V8 third gen would, mine even has everything a T/A would munus 2 cyls.

With my current combination of 11.5:1 SCR, big cam (barely streetable), with self made headers and full port job, we should see around stock LT1 numbers with it.


If you remember correctly, it wasn't that long ago you and junkcltr were giving me advice on welding. My turbo kit was the first real experience I had with welding where leaks and strength were of an up most importance - all on the above mentioned $129 (on sale, lol) flux core HF machine.

I have since built several turbo kits and my welding has exponentially increased, i still use the same welder until I find another in the budget. I'm sad I just missed a deal on a good working Miller gas MIG for $450 (he ended up getting $1200 for it), but timing is everything.

One car i turbo'd is posted here in the power adder section called "0-6psi < 48hrs" and it runs a mid 13 in a FWD body (much slower than an fbod) at 105 with 6psi. The thing pulls like mad and he is still getting in the high 20's for mileage with a fairly large street cam.

To the original poster, you are going to have to decide if doing the work yourself is feasible of not. I was able to build my first setup on a stock motor for about $1200 if you included the cost of the welder, using ebay parts and finding locals who could help me with materials. This also was done where i had or had access to the tools necessary to complete the job.

83 Crossfire TA

I was noting an overall mediocre response, not yours specifically…

Depending on the year we’re talking about something rated roughly 140hp… where the performance V8’s were all in the 190-245hp range. 7-10psi should easily get you into that range, and the lighter weight should get you a faster car. An iron headed SBC will tip the scales around 650lbs so you should be saving about 300lbs over a V8… I’m convinced that someone good at what they’re doing should be able to get a stock/stockish v6 thirdgen with a turbosetup running 10-15psi boost into the high 12’s, and significantly faster than the best of the factory V8’s.

Sounds like a lot of fun to me. Even more so, there is no good reason why with some careful choices you shouldn’t be able to build one of these up to make in the 400-450 hp which should put a V6 car in the mid/low 11’s at close to 120mph…

WRT to welding, I wouldn’t recommend that welder for building a turbo kit… it’s sufficient for tacking parts together, but it is quite difficult to get a nice weld with. My brother actually had me stop by and try his after he wasn’t able to do much more than tack weld with it and after some adjustment I was able to run a nice bead, but it wasn’t as easy as it would be with other welders.

Obviously, if he wants to learn to weld we should be able to talk him through it, but part of my point was that he actually has a realistic idea of budget and if he wanted to make the parts and farm out the final welding he could.

project89

a stock wieght stock motor save for a cam,at 11-12 psi will put u just around 300 crank,enough for 13's nut it wont get u into the 12's,it takes over 19 psi to put a stockish motor into that range.all in all its not that bad the stock motor can take it and u dont have to port the heads or anything u just need to crank the boost.thats with a 52mm turbo

so id say with the 61mm u could prolly do the same for around 3 psi less boost but ur really not gonan get out of the mid 12's with the stock heads

if u look at my current setup 3.1 ported heads custom cam,6psi works out to just around 320 @ the crank so u can deff see the diff in porting the heads will make.

firstfirebird

140bhp is the 3.1 rating. Many have dynoed their basically stock cars (even some with a few bolt ons) and they make right around 100whp, especially in auto's. What "performance" V6's are you mentioning? Even today with VVT and variable intakes we are only seeing 260ish hp (285-300+ DOHC's) in stock GM cars.

I have seen as much as 340hp N/A in a race equiped sprint car yielding a 3.4 v6, and there are a few guys well into the 400's boosted.


Right now the fastest street trim V6 fody's are in the 11.8x range with 3800's in them, one car is in the 8's, but it's nowhere near a street car (also a 3800).