Advantages to bigger turbo on pump gas?

[strikeeagle]

I think what we're seeing here is the effect of a larger exhaust housing when a smaller housing has been pushed beyond what is reasonable. Nonetheless, I defy anyone to strap a TE45A on a bone stock TR and go faster with it.

Now Woody, I agree with you, we've got to get some of these recipes documented, because if I can run 25 PSI on pump gas and go 11.2 then I guess I'm inclined to start all over.

 

[Wes]

Originally posted by Wht87T
I have a CPT65, and my alky kit is on the way. I'm gonna have a blast with that combo. If you guys want any info on the SMC kit just call up Steve, he'll answer all the questions you want.

John

so you think your gonna need that alky kit? how much boost do you plan to run ...maybe i have some sort of "magical" motor...but if you keep these damn cars tuned right..you wont need alky ..i run 23-24 lbs of boost...i rarely get any knock whatsoever..and if i do it stays in the .4-2 degrees of retard...my o2 millivolts always look great ...i just dont understand what can make you turn to the alcohol

 

[Intercooler]

Originally posted by strikeeagle
I think what we're seeing here is the effect of a larger exhaust housing when a smaller housing has been pushed beyond what is reasonable. Nonetheless, I defy anyone to strap a TE45A on a bone stock TR and go faster with it.

Now Woody, I agree with you, we've got to get some of these recipes documented, because if I can run 25 PSI on pump gas and go 11.2 then I guess I'm inclined to start all over.

Well I did manage an 11.5@118 with pump gas, RA-93 chip and breaking up. I think 11.2's were definately in the bag and this was only 19.5 PSI!

 

[azgn]

and your combo was? I can believe 19 psi....what does your car weigh?

just trying to get smarter........I too, am going to start over....everything I have done is for naught!

 

[RealFastV6]

Oh yeah, the Felpros have nothing to do with it either guys right? Those things are junk! My brother's girlfriend's father ran 9.90s on a chip.

Tune Tune Tune, fuel fuel fuel, boost boost boost.

 

[Intercooler]

I had T63E, 55's, AC 9" 3200, Ported big valve heads, 218/218 cam, V2 and probably 3400 lbs. of car.

 

[Bmason]

Well, maybe I have one of those special cars too!

I can run +20 psi on 93 octane and not ping. But, it's not like that every day. On those cold HG popping mornings/nights, I have to take it easy. But for the most part, 20psi isn't unrealistic for my daily driver. Stock block, stock heads, stock cam, FM and PTE-60. I can tell you that my stock turbo wasn't trying to have any parts of that 20psi no pinging nonsense.

Woody, Strikeeagle, there's no need to start over. With my car, I think it has more to do with the state of tune, more than anything else. As you already know, some of these cars react totally different than others! Heck, this thing will run all day long at +25psi on 104 unleaded...go figure!

As for GNSCOTT running 11.2 on low 20psi...beleive it. I happen to know exactly where that motor is, and it runs 11.5 on 19psi and get this....it has hyper pistons too! Maybe on second thought, some of the recipes can be changed!

-Bobby

 

[Richard Inglett]

Big Turbos = Fun (But Not Forgiving)

Definately contrasting comments concerning turbo size and boost. Quite frankly, if you have gobs fuel and can move the air; it is possible to run uncomfortably high levels of boost on pump gas with larger turbos (i.e. TE45, TE63-1 & larger). However, large turbo will make pay if you overboost. A 4 or 5 psig spike with a stock or TE44 turbo is not a big deal, you'll be forgiven. Do the same with a large turbo and it is all over. Nonetheless, as long as you are careful and patient I say bolt on the big turbo and rip up some concrete. Just note that a bigger turbo will give you more with less boost so for everyday driving, please save the 20 plus psig boost for the good gas.

Answer is big turbo is OK but you have to have the FUEL!!!

 

[Wht87T]

Wes

Something is missing. It has to be in the chip or the fuel pressure settings. I'm totally lost.

 

[Richard Inglett]

Lots of Variables

Wht87T

There are so many variables so let me list some scenarios that I have experienced to help illustrate the basics. Assuming use of 93 octane gas and good programming, typical boost limits are as follows:

- Stock turbo with stock injectors: 17 psig
- TE44 with blue tops & front mount: 14 psig (20 psig with alcohol injection)
- TE63-1 with blue tops, ported heads & front mount: 7 psig
- TE63-1 with 009's, ported heads & front mount: 8 psig
- TE63-1 with Siemens 55's, ported heads & front mount: 12 psig (Translators permits 15 psig)

In general, expect to run less boost with bigger turbos and pump gas.

 

[Intercooler]

Richard,

Your numbers are waaaaaay off! IMHO

 

[GNVAIR]

I agree. I was always able to run more boost with my TA49 without knock than I was with the stock turbo. This was on the same chip and injectors as well, so I dont buy into your thinking with the TE44 as it would be slightly more efficient than my TA49 and thus allowing it to run MORE boost. I havent had a chance to try my TE45A yet, but I would beg to say it would also be along the same lines.
As I see this whole thread is turbo choice is a total matter of combo. You have to make some rather severe performance compromises to run pump gas and even then, you will not be going very fast. I run alky so I can have the best of both worlds. I will also be running a fairly loose convertor.
As with most cars, you will probably have to experiment to find out what suits your taste best as there is no clearly written in stone answer here.

 

[Steve Wood]

Originally posted by RealFastV6
Oh yeah, the Felpros have nothing to do with it either guys right? Those things are junk! My brother's girlfriend's father ran 9.90s on a chip.

Tune Tune Tune, fuel fuel fuel, boost boost boost.

Your brother's girl friend must be running a MaxEffort then as a number have been into the nines with the ME....You need to get out more often.

 

[Steve Wood]

This is an interesting topic and one that is not set in stone. I have seen more than one that was able to run more boost than others. It did not always seem to equate with power, tho'.

I had no problem running 21# with a 221 deg cam. It was soft on the bottom end but I ran more compression and more converter. The common denominator is cylinder pressure and charge temperature I think.

93 octane is very sensitive to the conditons that cause detonation and once it starts to detonate, it is hard to stop it. Race gas seems a lot easier tune for detonation prevention. I am not talking about the same boost levels for each, obviously.

The bigger turbos heat the charge less at a given boost level than do smaller turbos. On the other hand, they are harder to spool, more prone to surge, etc.

I am a bit leery of telling anyone that they will be able to run substantially more boost with a big turbo than a small one if nothing else changes in the combination You might get a pound on the average, but maybe not.

There are exceptions to every rule and it is probably bad policy to call some a liar until you have put your boost gauge on his car.

 

[Berman]

Originally posted by strikeeagle
A larger turbo will:

1.) Exacerbate turbo lag.

Can't argue with that, but turbo technology has come a long way since 1986. A te-44 spools basically instantly anyway.

Hell I have a PT52 with a stock converter on my t-type, which according to most people here would be lag-city. No. Spool it up to 0, launch, and within about 7 feet I'd say it's into full boost. (spool it above 0 and you will just spin the tires like crazy on launch, I'm talking about street tires obviously).

2.) Provide a HOTTER charge air temperature.

Umm.. No. A bigger turbo will be more efficient. More efficient = less heat. I garuntee you that the air coming out of my PT52 at 19 psi is much cooler than what's coming out of a stock turbo at 19 psi.

3.) Be more likely to surge.

Blow-off valve. Nuff sed.

 

[Richard Inglett]

I Said Typical. More is always possible.

Please let me clarify. The examples I listed were generated about five years ago. Programming and equipment have come a long way since my experience with a TE44 and blue tops. Furthermore, do not question that a TA49 will let people run the same boost as stock without downsides. However, don't expect to do the same with a TE45 or better yet... a TE70. Not saying it can't be done. there is just more involved and more at stake to make it happen.

 

[James Racing]

Originally posted by GNSCOTT


Matt, i couldn't agree more. I'm wsing now iever changed my old combo. I guess i figure when i'mdone,i'll end up selling the car. My combo was..
AC 3k stall
CPT 66 bb
218 cam
bone stock longblock (except cam above) no head porting, stock tb, plenum etc.
V-2 fm
good fuel system
good exhaust system

I ran 11.2's @119 with 94 octane, 25psi, 18 degrees of timing and zero knock. I wicked it up to 26psi and got 3 degrees. i put in a race chip ad it knocked immediatly @ half throttle. Drove the car almost 200 miles each way to and from the track, and had fun.. I'm sure wth a race chip and good fuel it would have been 10 second slips for me

And then- you woke up. I've heard from
several local TR guys what you *really* ran. It's one
thing to run a legitimate number and another to get
on the Internet and talk a bunch of BS- know what
I mean?? How is it that someone who cannot even
figure out how to install a Scanmaster runs these
times?? See below:

http://www.all-story.com/issues.cgi?action=show_story&story_id=100

http://www.turbobuick.com/forums/showthread.php?s=&threadid=25440

 

[strikeeagle]

Two things are clear:

1. Several of you guys need to get with the compressor curves and understand them, because you're having larger, less efficient turbos providing cooler charge air??? What do you suppose "inefficiency" manifests itself as???

2. Where the hell are these gas pumps?

 

[RealFastV6]

Originally posted by James Racing
And then- you woke up. I've heard from
several local TR guys what you *really* ran. It's one
thing to run a legitimate number and another to get
on the Internet and talk a bunch of BS- know what
I mean?? How is it that someone who cannot even
figure out how to install a Scanmaster runs these
times?? See below:

http://www.all-story.com/issues.cgi?action=show_story&story_id=100

http://www.turbobuick.com/forums/showthread.php?s=&threadid=25440

I was there when Scott ran his car, but thanks for your input James. (In fact, we drove it to the track that day.)

 

[RealFastV6]

Originally posted by strikeeagle
Two things are clear:

1. Several of you guys need to get with the compressor curves and understand them, because you're having larger, less efficient turbos providing cooler charge air??? What do you suppose "inefficiency" manifests itself as???

For the record, Im not so much talking about these guys with the HUGE turbos. But, I will go so far as to say that with a stock block/heads/cam/converter/gears/tires that something along the lines of T60 turbo will be able to run 2 or more lbs of boost on the same gas (provided PLENTY of fuel volume is there).

But anyhow, this goes to show, there is life above 20psi on pump gas.

2. Where the hell are these gas pumps?

CT... you guys all wonder why we pay so much for gas... well, its Magical gas.