turbo or supercharger

[Joseph Upson]

The new 3.6L DOHC motor is the only 60 degree engine I'm aware of that has a forged rotating assembly including pistons. The closest you can get to using them is in the 3500 block which has a 94mm bore and 84mm stroke, the 3.6L has a 94mm bore and an 85.6mm stroke which depending on the pin placement in the piston might work out perfect if it brings the piston down 1.6mm because the 3.6L has a 10.2:1 compression ratio which suggests you would still have good compression for forced induction. The forged piston information is from GM not speculation or hear say. Even the main bearing caps are steel.

On a different note, until you see it documented there is no telling what type of material GM has used to manufacture various parts especially in the new 34-35 and 3900 the latter two offered with a steel crank and higher compression ratio suggesting a piston upgrade is warranted over straight cast given the added stress. Who knows. Regardless, todays cast piston is certainly a better part than those produced years ago.

Per GM Parts direct:

2006 Cadi CTS 3.6L piston= $50.60, rod $50.22
2006 Malibu Maxx 3500 piston w/pin only= $75.30 rods $42.12 and $29.86
2006 Pontiac G6 3500= $75.30 includes connecting rod

I would say it's worth investigating, I imagine the rod price difference for the malibu involves 3" and 3.31" differences for that year engine. 1.6mm is not a lot and it is very possible the 3.6L piston has the same pin location as that found on the 3500 piston and that's what resulted in a jump from 9.8:1 compression in the 3500 to 10.2:1 in the 3.6L. We just need to know the rod specifications to verify it. The forging process probably accounts for the price difference between the two.

The CTS pistons are forged aluminum and full floating in piston and rod.

[bjornmk1]

gpt pistons

the gpt 3.1 turbo pistons are from MAHLE and are somewhat stronger
than standard(or hypereutic) pistons.

they will hold about 12 psi reliable

15psi is wort forged ones...at least I would upgrade to
forged ones or turn down the boost to 8psi max.

just my 2cts.

[alainman15]

well than maybe i'll go down 2 around 8- 10 psi. i just want more power so i dont get wasted will racing.

if the tgp pistons are better than ill go with those i think unless anyone has any reason that can covince me

what is the octane requirement for a tgp

[ForcedFirebird]

The new 3.6L DOHC motor is the only 60 degree engine I'm aware of that has a forged rotating assembly including pistons. The closest you can get to using them is in the 3500 block which has a 94mm bore and 84mm stroke, the 3.6L has a 94mm bore and an 85.6mm stroke which depending on the pin placement in the piston might work out perfect if it brings the piston down 1.6mm because the 3.6L has a 10.2:1 compression ratio which suggests you would still have good compression for forced induction. The forged piston information is from GM not speculation or hear say. Even the main bearing caps are steel.

On a different note, until you see it documented there is no telling what type of material GM has used to manufacture various parts especially in the new 34-35 and 3900 the latter two offered with a steel crank and higher compression ratio suggesting a piston upgrade is warranted over straight cast given the added stress. Who knows. Regardless, todays cast piston is certainly a better part than those produced years ago.

Per GM Parts direct:

2006 Cadi CTS 3.6L piston= $50.60, rod $50.22
2006 Malibu Maxx 3500 piston w/pin only= $75.30 rods $42.12 and $29.86
2006 Pontiac G6 3500= $75.30 includes connecting rod

I would say it's worth investigating, I imagine the rod price difference for the malibu involves 3" and 3.31" differences for that year engine. 1.6mm is not a lot and it is very possible the 3.6L piston has the same pin location as that found on the 3500 piston and that's what resulted in a jump from 9.8:1 compression in the 3500 to 10.2:1 in the 3.6L. We just need to know the rod specifications to verify it. The forging process probably accounts for the price difference between the two.

The CTS pistons are forged aluminum and full floating in piston and rod.

I don't know if the cyl walls are thick enough to go to from 89mm to 94mm in the 3.1. Anybody know?

[alainman15]

I don't know if the cyl walls are thick enough to go to from 89mm to 94mm in the 3.1. Anybody know?

i think ur confused he is saying that they bave the same bore but the other just has a longer stroke

[ForcedFirebird]

Sorry joeseph, I see where you said if he used the 3500 block.

[ForcedFirebird]

i think ur confused he is saying that they bave the same bore but the other just has a longer stroke

But this means you couldn't use your 3.1, that's where I was going.

[alainman15]

But this means you couldn't use your 3.1, that's where I was going.

ok i get u. i knew that 1 it would be nice if it could fit but it doesn't so i guess my best is now after market. i was just informed that the tgps are cast like the others.

[timg]

Just a forewarning.

Putting on a supercharger or turbocharger is almost never cheap or easy (unless you happen to do that sort of thing all day, every day). Both will require custom fabrication and will probably result in some compromise to daily drivability. Both will require at least 91 octane gas.

For 15 psi, you should look into forged pistons. For 8-10 psi, stock will probably be fine. The temperature of the intake air and the tuning of the car will make HUGE differences in the amount of power you make and how reliably that power is made. Josh (malibuolds) has mounted the complete setup from a TGP on a non-TGP engine with 200k+ miles on it. That engine has held up just fine.

The supercharger from the Grand Prix GTP is a great idea if you either have a machine shop or know someone who does. Otherwise, the cost savings of the used supercharger will be completely blown on the mounting hardware for that supercharger.

Your easiest and cheapest option will be to try to make a TGP clone and hope that it doesn't blow up.

Tim

[alainman15]

91 octane eh? what about injectors would they be fine as is? and how can i lower engine heat so the motor doesn't over heat or mainly 2 try and avoid predetination with a lower grade fuel like 89 gas prices hurt now days (hope i got the heat & detination thing right) im usin 87 octane right now.

im just a cheap guy looking 4 a cheep way i guess. but what must be done, must be done if i really want it.

aww man I feel like an idiot right now.

[ForcedFirebird]

If you are interested in boosting your car, the difference in the gas prices will be insignificant in comparison to the money you are going to spend on doing it right.

[alainman15]

ya i think your right. its just that you have 2 keep putting gas into the car and it adds up. but boost doesnt come without sacrifice.

thx all i keep all this info in mind.

[Joseph Upson]

91 octane eh? what about injectors would they be fine as is? and how can i lower engine heat so the motor doesn't over heat or mainly 2 try and avoid predetination with a lower grade fuel like 89 gas prices hurt now days (hope i got the heat & detination thing right) im usin 87 octane right now.

im just a cheap guy looking 4 a cheep way i guess. but what must be done, must be done if i really want it.

aww man I feel like an idiot right now.

If you can do it yourself you'll save a good bit of money the first time you do it and even more each time after that:

MIG welder ~$250
Saws all to cut tubing ~$35
Mandrel bends/straight tubing ~$125 worth exhaust to turbo needs to be stainless or 14 gauge for longevity against the heat.
Turbo ~$350
Odds and ends ~$150

The most important items that is rarely mentioned in turbo projects because they are missing, GOOD, COMPLETE, TUNING, EQUIPMENT- a data logger and chip programming equipment ~$700 something with exhaust temp reading and wideband O2 sensing.

I've built enough turbo motors to know that for once I need to buy data logging equipment to find out exactly where changes need to be made and I'm going to take the Zeitronix route.

As for pistons to each his own, but until I get definative proof that stock pistons can't handle upwards of 15 properly tuned and cooled psi I'm sticking with stock. I've seen more examples of properly tuned stock pistons surviving long and prosperous boosted use. The break down stories I have read almost always involve some mention of poor tuning and a good bit of track time in that state. I don't intend to race so most of my driving would be sedate sports car driving.

I believe GM refers to hypereutectic pistons as cast also, I destroyed some firebird 3.4L pistons with severe detonation and they chipped up like hypereutectic pistons. How many boosted stock GM cars have forged pistons, and keep in mind GM doesn't tend to run anything on the edge for warranty reasons, there's almost always lots of room between stock and the limit.

If you want good power start with the largest 60 degree V6 you can get not just what you have, that way you don't have to turn the boost way up from the start. The TGP outfit will work on the other engines you just need to work in a larger turbo.

If you tune it properly you can run at least 7psi on 87 octane, if you use an intercooler and water injection together 10 or more.

Get a good up to date book on turbocharging and build your documented knowledge so that you'll have a better idea of what's possible.

The little import 4 cylinders are being run into the psi-teens all the time as well as the stock GM forced induction cars, don't be afraid. Someone needs to find out what the limits are.

[ForcedFirebird]

MIG welder ~$250
Saws all to cut tubing ~$35
Mandrel bends/straight tubing ~$125 worth exhaust to turbo needs to be stainless or 14 gauge for longevity against the heat.
Turbo ~$350
Odds and ends ~$150

The most important items that is rarely mentioned in turbo projects because they are missing, GOOD, COMPLETE, TUNING, EQUIPMENT- a data logger and chip programming equipment ~$700 something with exhaust temp reading and wideband O2 sensing.

Moates.net has GM burning equipment and you can get started for around $200. In your list, you forgot wastegate, BOV, silicone couplers and FMU for a MAP equipped car. Not including the cost of tools, my parts cost almost $1000 (including an intercooler).
And I agree with you that the cast pistons will hold up if tuned properly.
Here's a link to 30PSI on stock cast pistons. First detonation made the piston look like crumpled tinfoil.
http://www.thedodgegarage.com/the_reliant.html

[Joseph Upson]

Moates.net has GM burning equipment and you can get started for around $200. In your list, you forgot wastegate, BOV, silicone couplers and FMU for a MAP equipped car. Not including the cost of tools, my parts cost almost $1000 (including an intercooler).
And I agree with you that the cast pistons will hold up if tuned properly.
Here's a link to 30PSI on stock cast pistons. First detonation made the piston look like crumpled tinfoil.
http://www.thedodgegarage.com/the_reliant.html

First that's a beautiful bird, looks just like my 85 did, same color, I'd like to find a nice GTA.

I didn't forget anything, the couplers and optional external wastegate and BOV were included in the $150 extra. I use internal wastegates which have come with my turbos and as for an FMU I do all tuning in the chip, no add on fuel or timing management. When I'm consistently on a fast internet link I'll try to post my sources for good prices on parts particularly the silicone that gets very pricey. I've seen some ~$50 external wastegates and lower priced BOVs on Ebay however the problem is finding a reasonably priced fully adjustable unit as opposed to spring limited.

By using the internal along with the TGP solenoid setup I can program in desired boost levels over the RPM/MAP range. I also over estimated the tuning equipment costs to allow some price flexibility as well.