Best turbo for pump gas? TA33? 49?

[fullahotair]

Hey guys,

I was wondering what everyones thoughts/experiences were for the best turbo for pump gas. I am being realistic in that i won't be running much else than premium gas in my 85GN. I know a lot of people prefer the TA49 and that its sweet spot is allegedly 23 to 25 psi. Is that a psi that can be obtained on premium pump gas? I don't want to get a turbo who's real potential is only with race gas. I am curious to know the best turbo for a car that will only be using pump gas. Will a TA33 perform the same as a TA49 on pump gas??? Any help would be greatly appreciated.

Thanks,
Nathyn

 

[cool 84]

I think the more air your motor flows, the lower that spot will be. With ported heads, cam, intake, downpipe, that spot should be lower. You won't be disappointed with it, that's for sure. I've heard the 33 is a 49 in the stock housings. If that's true, go with the 33. If not I would have a 49 put in your stock housings rather than try and adapt an actual 49 to fit.

 

[1QUICK85]

I love my TA49.............it spools great with my stock convertor......I cannot notice the difference really......or maybe it is the breaking the tires loose on a 20 mph roll(and that is with just 10lbs of boost) that out weighs the little extra second it takes to spool. But, my V2 intake is probably helping bring the sweet spot down a little??

Nick

 

[fullahotair]

Would i even notice the difference between a TA49 and TA33, since i will probably only ever run premium pump gas? I am curious if anyone has notice a real difference.

Anyone have a picture of a TA49 on their car? from what i understand you just have to mod where the turbo goes into the manifold correct?

Thanks,
Nathyn

 

[irockwithdirt]

My understanding is that the 33 is in fact a ported stock hotair housing with a 49 wheel. It is not as simple as just changing the wheel.

What I don't understand is why it is advised to weld an outlet from a stock hotair turbo on a ta49 to make it fit?

I'll admit I'm going into this blind, but it looks easy enough to just make an adapter. With a little fabrication it should be a bolt on.

Guess I'll find out if I'm wrong

 

[fullahotair]

oh and the other thing is.,...i may be able to pick up a 10,000 mile TA49 for $350 with a turbo saver on it. So that kinda leans me to picking up a TA49, eventhought the TA33 would be a direct bolt in.

 

[Nocooler]

Originally posted by irockwithdirt
My understanding is that the 33 is in fact a ported stock hotair housing with a 49 wheel. It is not as simple as just changing the wheel.

What I don't understand is why it is advised to weld an outlet from a stock hotair turbo on a ta49 to make it fit?

I'll admit I'm going into this blind, but it looks easy enough to just make an adapter. With a little fabrication it should be a bolt on.

Guess I'll find out if I'm wrong

TA33 is not a 49 wheel in a hotair housing. The 33 compressor is marginally bigger than a stock 86/87 compressor. The 33 uses the stock turbine wheel. The 49 compressor and turbine are considerably bigger than the 33. Twins has both turbos and they spool completely different.

 

[irockwithdirt]

http://www.turbobuicks.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=005636

As I said, I'm learning Just what I was told.

 

[Twins]

My car won't build more than 2 psi against the brakes with the 49. Same set-up same tuner ect it would build 10+ psi with the 33. I'm not saying other people don't have better luck, but it sure didn't work for me.

I trapped at 103.5 with the 33 spinning 23-24 psi, and 103 with the 49 spinning 21-22. The diff was 13.0 vs. 14.0 et's because the 49 wouldn't spool at the line. I'm getting mad just typing this thinking about how long I sat trying to build boost. I wore a friggin helmet at the track to have 14 sec GN. What a dumb ass.

Anyway I spent one summer driving around on pump fuel and 15+ with the 33 and it was the best memory I have of the car. It spools as fast as a stocker IMHO and is the best thing for a fairly stock car.

Check with John C. for a new one.

Just my $0.02.

 

[fullahotair]

so i have been reading that for instance 10 psi on a TA33 is not the same as 10 psi on a factory turbo, due to air flow. The TA33 flows twice as much air. In a cylinder of your engine, you have a fixed volume, and if you have 10 psi in both scenarios wouldn't the resultant power be the same? Isn't 10 psi in a cylinder 10 psi, no matter how you get it (aside from the density/temp of the air). You have to cram the same quantity of air in a cylinder to get 10 psi regardless of turbo correct? Perhaps i am overlooking something simple here...


Thanks,
Nathyn

 

[cool 84]

Originally posted by Nocooler
TA33 is not a 49 wheel in a hotair housing. The 33 compressor is marginally bigger than a stock 86/87 compressor. The 33 uses the stock turbine wheel. The 49 compressor and turbine are considerably bigger than the 33. Twins has both turbos and they spool completely different.

Finally, this is what I've been wanting to know. In this case, go with the 49. There is no reason to go any smaller because the 49 spools very close to a stocker and will go mid 11s. Some have even stretched it to high 10s. If you have a problem spooling a 49, something is seriously wrong with the car. I could get whatever boost I wanted against the brake with a 2,600 stall convertor. From a roll it spooled like stock. The only time there was a little more lag than stock was from a dead stop without spooling it up before launch and even then it wasn't bad.

10psi is 10psi period. What a bigger turbo does is heat the air less giving a denser charge at the same psi. So you are getting more air at the same psi. It also frees up exhaust back pressure.

The 12.9@110mph in my sig was with a 49 with boost at 13psi for most of the run. I felt that it had a lot more left in it because at the track it felt much slower with the problems it had that day then how I usually ran it on the street with 19-20psi.

 

[Twins]

.I'm about as far from an expert as you can get but I think it all has something to do with heat. We all know hot-air is tough to work with and an efficient huffer will produce less heat for X amount of boost.

So if a stocker is working at 85% to produce 10 psi because it's max cfm is 390 a 33 might only be working at 50%. (33's are rated at 850). More heat = well we all know bad things like det. and a crash course on "how to do head gaskets on a hot-air".

I may be off base here (and please chime in to inform both of us) but I think that's about the long and short of it.

Don't count on more than 15 psi on pump fuel with any amount of timing though no matter what. Alky really works well for more boost on pump fuel if you can get it to work. After the taste of 22-23 psi 15 psi is just like being stuck with the fat sister. Not really worth doing IMHO .

 

[fullahotair]

cool that answers my question really, i just didn't give the generation of increased temps/density enough credit.

To fit the TA49, i know there is some fabrication involved - -does anyone make the parts needed for this?

Thanks,
Nathyn

 

[cool 84]

Originally posted by fullahotair
cool that answers my question really, i just didn't give the generation of increased temps/density enough credit.

To fit the TA49, i know there is some fabrication involved - -does anyone make the parts needed for this?

Thanks,
Nathyn

Since you're buying the turbo used, have John Craig weld the adaptor if you can afford it. Usually it's no more expensive to have a 49 installed into the stock housings.

 

[fullahotair]

Cool84,

Not clear on what you mean "Usually it's no more expensive to have a 49 installed into the stock housings." Do you mean its no more expensive than a TA33??

how much would it cost to have John Craig weld on the adapter?

THanks,
Nathyn

 

[cool 84]

I meant if you were buying a new one it shouldn't be more expensive to send your old turbo and have the wheels put in your stock housing. Since you got a good deal on a used one I would go with that. Don't know how much the adaptor is because I don't need it with the intercooler.

 

[buickpower]

ta33

just for the record, the ta33 flows ~700cfm, and the ta49 flows ~800cfm. Also, the ta33 does not have the stock turbine, it is a good deal larger with alot different (higher) pitch. i did a bunch of research when i bought my 33 and just wanted clear some stuff up. Hope the info helps.

 

[fullahotair]

Yup,

Thanks "buickpower". let me know how you likey our TA33. My deal with the Ta49 has fallen through, so maybe i'll get a TA33.

THanks
Nathyn

 

[Nocooler]

Email Twins - he has a TA33 he might want to get rid of.

 

[fullahotair]

Thanks,

I'll do that.

Nathyn