With a 64mm at 70%
Unless the tune is off
It should never split a 109 down the middle.
More power 6776
- Thread starter Ttype6
- Start date
Unless the tune is off
It should never split a 109 down the middle.
BaldMenace
Member
- Joined
- Sep 25, 2013
I've got a Garrett turbo with journal bearings and if I'm going to use something else now is the time to make that move. I've got a 109 block, 4340 stroker crank, billet center caps. Ported heads and Intake. Roller cam and the desire for instantaneous boost.
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
Team Grumpy went 9.98 at 138 on a stock stroke 109, 6776, 5.7 alky chip, Translator, 9/11 convertor a gazzillion years ago. Boost was approximately 30 PSI. I can tell you when the CEA turbos came out...they were a game changer...even for what I was doing.
Dynomans car went 0 to 34psi off the footbrake in under.5 sec.
That's 990hp with a 6771 .85 3 bolt triple bbb.
With back pressure at 1.8
husek converter and trans.
Boost is as instant as a turbo car can get and great back pressure reading in a 3 bolt for that power level.
Super fun combo to drive.
Now do most need that kind of power
No
But
If you want 700 or 800hp
any power level you choose is damn near instant
After owning this car for 34 years I finally purchased some compression fittings copper tubing, a pulse damper, and a 100 PSI sensor and took the car out and measured my back pressure. At 24.5 lb of boost I had 45.1 PSI of drive pressure which puts my drive pressure to boost ratio at 1.84 to 1. Again, I have a 273 cubic inch engine and a 6776 turbo with a precision .63 A/R turbine housing. I know many people over the years have believed and or stated that the precision .63 housing is more like a .70 - .72 A/R, but when I talked to someone at HPT the other day who had worked with Harry when Harry owned precision, he said it was much closer to 63 and nowhere near 70.
Turbine A/R uses two dimensions, the nozzle area over the radius to that area typically measured at the tongue, so it does not fix or indicate the actual size of housing. It simply is what is, you could have two housings with a .63 A/R and one could be 10 (or any number) times the size of the other. The precision housing is physically larger with more nozzle area than the original garret, but still a .63 A/R, so I am guessing someone came up with a bad analogy early on when it was released.
Nice
Now you know where the turbo is at
As far as ex housings
Not sure who you talked to over at hpt but.....
Not sure I buy into whos casting is a real ar but they are measured a certain way.
I can tell you a pte .63 and .85 ex housings are larger than the tnetics and Garretts in 3 bolt.
The .85 I understand tnetics and garret only made .82.
But the .63 weren't even close.
the initial opening of the pte was 2.5 inches
Tnetics was around 2.25 and that's on an .82
If memory serves.
And on the inside they weren't close
The pte .63 was closer to the tnetics. 82 but not as big on the inside.
So it was easily assumed the pte .63 was larger than .63. And closer to a .70
As many believed tnetics/Garrett's tooling was more accurate and tnetics and Garrett were the same size
After porting and modifying many 3 bolt ex housings
I do believe the pte was not a true .63 and the tnetics stuff is a true .63. As well as the garrett 3 bolts from back in the day.
I know that the 4 bolt stuff is bigger even when the numbers are close to a 3 bolt.
Back the fact is the pte was larger than both tnetics and Garrett leads me to a simple conclusion.
the turbo should have some but not too much more in it
There is a good chance if you can increase more pressure on the gate and get more boost you will see backhand climb quickly for another 50hp.
This is where looking at fuel usage will tell you exactly where things are at
How much fuel is the car using?
As you apply more on the gate,see more boost,look for fuel usage
That behavior will show you how much power your making and when your out of turbo.
Example #1 would be a 6 psi gain and very little fuel usage.
Example#2 would be 6 psi gain in boost needing another say .5 point in fuel off your wideband.
I did discover while I had it apart that the wastegate hole in the turbine housing is very very close to the diameter of the puck as you can see witness marks on the very outside edge of the diameter of the puck and just around the edge of the opening of the hole in the turban housing. I didn't realize I went that large but it was definitely blowing the wastegate open and I couldn't achieve more than 20 or 21 lb of boost and this was when I had it on my smaller engine so I simply added an external spring to pull on the wastegate lever and I could easily achieve 28 to 30 PSI of boost but I believe right now my turbo charger is putting out everything that it can. It's just easier to blow through this bigger engine but I guess I should wire the wastegate shut and see if I can get any more out of it then I'll know for sure.
Well, I guess I should be glad that I have a precision 63 and not Garrett.Nice
Now you know where the turbo is at
As far as ex housings
Not sure who you talked to over at hpt but.....
Not sure I buy into whos casting is a real ar but they are measured a certain way.
I can tell you a pte .63 and .85 ex housings are larger than the tnetics and Garretts in 3 bolt.
The .85 I understand tnetics and garret only made .82.
But the .63 weren't even close.
the initial opening of the pte was 2.5 inches
Tnetics was around 2.25 and that's on an .82
If memory serves.
And on the inside they weren't close
The pte .63 was closer to the tnetics. 82 but not as big on the inside.
So it was easily assumed the pte .63 was larger than .63. And closer to a .70
As many believed tnetics/Garrett's tooling was more accurate and tnetics and Garrett were the same size
After porting and modifying many 3 bolt ex housings
I do believe the pte was not a true .63 and the tnetics stuff is a true .63. As well as the garrett 3 bolts from back in the day.
I know that the 4 bolt stuff is bigger even when the numbers are close to a 3 bolt.
Back the fact is the pte was larger than both tnetics and Garrett leads me to a simple conclusion.
Ah, I see. Have you had an opportunity to compare the precision 63 with the new HPT 70 turbine housing?
No, but I am planning to save my pennies, because an HPT will be my next turbo.
Putting the external controller and co2 will allow that increase in a controlled manner.
It would raise your back pressure and peak the flow earlier in the rpm range.
Exactly.
It’s a complete tear down to switch comp covers most of the time. The backplates are different. I wouldn’t bother unless you’re maxed out on the turbo as it is. Like 9.60-9.70 137mph. If not you’re chasing after scraps and your money is spent elsewhere. Use the ECU to control a pair of solenoid valves and configure your wastegate for external pressure. Use a light spring in the wastegate. Use CO2 to hold the gate closed. ECU should/can be configured to control the pressure in multiple ways. Commonly and somewhat easily dome pressure can be targeted and ramped as needed. The lowest pressure you can “control” will be the spring pressure
