turbo for pump gas..

[fullahotair]

I posted this thread on the hot-air section, but i guess it is more appropriate over here.


I have an 85 GN, that will probably always see premium gas. Race gas will not a be a staple in its diet. What turbo will be the best bang per buck for a hot air with premium gas. I don't want to get a turbo that will perform the same as a lesser one unles i use race gas.

Any help would be greatly appreciated...

Thanks,
Nathyn

 

[cool 84]

TA49. It's a big jump over the stock hotair turbo and unless you have ported heads/intake, and a lot of airflow I doubt you would see much difference with a bigger turbo. The hotairs are kind of weird though and seem to like things on the big side whether it's a turbo or a cam. What mods do you have?

 

[fullahotair]

well technically none installed yet, but i have the following (except the trans +, and headers)

86/87 comp
Trans +/LS1
Ported/polished heads and intake
poston headers
2.5 Hooker exhaust
2.5 atr dp. and up-pipe
42.5 injectors
980 valve springs
307 fuel pump (hotwire)
K&N filter

I am accumulating the parts, and i am putting them on in stages....

I hear the TA49 has a sweet spot at 23 to 25 psi...can i get that with pump gas?


Thanks,
Nathyn

 

[bishir]

I hear the TA49 has a sweet spot at 23 to 25 psi...can i get that with pump gas?

Not even close.... unless you want to grenade your engine..

You'll need race gas or alky before you can even approach that boost level..

 

[SITHV6]

Originally posted by bishir
Not even close.... unless you want to grenade your engine..

You'll need race gas or alky before you can even approach that boost level..

was running 26 psi on the streets with no audible knock with a TA49. my biggest enemy was my coil harness frying out on me!

 

[bishir]

On pump gas? What are you doing that everyone else isn't? Not using a scantool? Is that why you're rebuilding your engine?

 

[cool 84]

The hotairs are weird, a couple have been known to run around 20psi on pump gas and no alky.

 

[SITHV6]

Originally posted by bishir
On pump gas? What are you doing that everyone else isn't? Not using a scantool? Is that why you're rebuilding your engine?

I'm not doing anything special that I know of, lots of little things that help keep detonation down maybe. jet hot coatings, a nice KB FMIC, fuel may have been on the marginal side with 40lbs. and 190ltr hot wire pump. it WASNT the combo that was flawed...had my shop mech friend who built the motor with me the whole 90 mile trip up to west palm moroso because he was wondering if my TR War stories were true....black marks left at 70mph....guage reading 26PSI etc etc. well it WAS. what KILLED my motor was the DIS harness wiring. after 16 years of abuse and cross country trips it was just about fried. while he was under the hood his elbo bumped one of the bad wires and the car Shut Off in the staging lanes! right there I should have pulled the car for the night....but nooooo ....wanted to run that pretty new white vette next to me! even with a blown head gasket it still ran a 12.80 (beat the vette though!)

 

[fullahotair]

So it appears the TA33 or TA49 will be best choices...

Thanks for the info guys

Nathyn

 

[turbo buicks]

let me get this straight. with a TA-49 you can run 25 psi on a hot air car without detonation and without an intercooler on mpump gas???

 

[cool 84]

Originally posted by turbo buicks
let me get this straight. with a TA-49 you can run 25 psi on a hot air car without detonation and without an intercooler on mpump gas???

I wouldn't try it that high but yes, you can get in the 19-22psi range on a hotair on pump gas. Sounds weird I know but when my dad's car was a hotair that's what we ran with a scan tool and only on the 1-2 shift would we get minimal (less than 1 degree) knock. It had to have been a factory freak because with only a chip, K&N, 21psi, pump gas and street tires it went 14.0@100mph.

I also could run more boost before I added an intercooler and this was after getting my 02s back up in line with where they were in hotair form. With the intercooler I'm stuck at 16psi on pump gas but it makes way more power that way. It goes with what I've always believed and that is you can make more power for a given octane with a good intercooler but it doesn't always allow you to run more boost for the same octane.

 

[turbo buicks]

WOW. WHAT WAS THE TIMING ON THE HOTAIR MOTOR? HOW RICH WAS IT?