Well, its IMO true the head is the limiter.

[turbows6]

Yeah, id say that a really big hot side turning over 6k rpm would probably make 9 sec power on lower boost. Fwiw, my motor is over 9:1 compression. That probably doesn't help either. It does make for better throttle response and gas mileage though.

 

[turbows6]

Maybe I'll put gaskets on it, turn the boost and timing down a hair and see if it will make a glory pass in the 9's. lol

 

[TT/Ameasap]

Screw that glory pass. Keep running 10.3 and have fun.

 

[1fastcobra]

Steve C. (TTA850) worked with Harland Sharp years ago to complete. I have the 1.6's

Joe

I run the 1.7 rocker ( Harland Sharp)
Stock tta rocker is 1.65
# 1 (440) 238 3260 there number

 

[rollie]

What timing were you are at WOT

 

[turbows6]

21/19

 

[turbows6]

21 at the top of 2nd when it went.

 

[TTA976]

I run the 1.7 rocker ( Harland Sharp)
Stock tta rocker is 1.65
# 1 (440) 238 3260 there number

Thank you, I didn't want to modify the stock valve cover so I went with 1.6

 

[TTA976]

21 at the top of 2nd when it went.

Starts happening around the 1000' mark ?

Joe

 

[TTA976]

21/19

I wonder if you lowered the boost 1.5# and dropped the timing to 18.5/17 if you would have an issue?

Joe

 

[we4Mateo]

I run the 1.7 rocker ( Harland Sharp)
Stock tta rocker is 1.65
# 1 (440) 238 3260 there number

I thought TTA's ran the same stock 1.55:1 rocker as the GN? Please correct me.

 

[we4Mateo]

DP is another issue. If we could turn the turbo exhaust side facing the back of the car that would help a lot... Run it straight out without the 90* elbow.

I would think that the Buick 3 hole exhaust housing would be a problem way before the downpipe or the exhaust runner. If air is stacking up there, it's probably a result of the turbo exhaust housing restriction more than anything. I don't know, just thoughts.

 

[TTA976]

I thought TTA's ran the same stock 1.55:1 rocker as the GN? Please correct me.

Stock TTA rockers are 1.67-1.7 ***edit*** they measured 1.62

You will have to modify the center valve cover studs to fit the rockers. 1.6 you do not

Joe

 

[TTA976]

http://www.turbobuick.com/forums/threads/tta-roller-lifters-rockers.174106/

Here is an old post. Maybe it was 1.55

Joe

 

[rollie]

21/19 isn't a lot of timing if he is running alky or 110 race fuel

 

[bison]

21/19 isn't a lot of timing if he is running alky or 110 race fuel

What should his timing be if he's trying to make 9 sec power with those heads?


BPE2013@hotmail.com

 

[bison]

http://www.turbobuick.com/forums/threads/tta-roller-lifters-rockers.174106/

Here is an old post. Maybe it was 1.55

Joe

Maybe someone can go verify this with an indicator so I can clean up the incorrect info?


BPE2013@hotmail.com

 

[bison]

I wonder if you lowered the boost 1.5# and dropped the timing to 18.5/17 if you would have an issue?

Joe

The issue would be losing 40-50hp. I don't disagree with doing either but the operating range of the engine would need to be changed to offset. Not gong to happen with current CR, cam, and turbo.


BPE2013@hotmail.com

 

[turbows6]

I might put a dial indicator on and check the valve lift and see what the ratio is. I checked valve to piston clearance, but never checked the rocker ratio.

 

[BEATAV8]

The DP isn't an issue at all. A good fabricator can easily fab one. More turbine with the correct cam and use nitrous for spool assist. Moving the engjnes peak mass efficiency up the rpm range with a little less mass efficiency will do it. You don't need more boost. You need more rpm. 9's with effective operating range 5800-6300 should be plenty to get 9 sec power with boost in mid to low 20's. Get the converter to flash to 5800 with the correct turbine, CR, cam, cam timing, and a well worked set of heads.


BPE2013@hotmail.com

this makes perfect sense.

it might be ironic? but I'm working through the same scenario on my setup right now. Mine was lifting the head too. Sounded like an exhaust header leak at WOT. Did it for quite a while before I found out what it was. The cometic head gaskets were very forgiving and allowed the head to lift and leak combustion gas without blowing out and dousing the crankcase with coolant so I was fortunate to avoid all that drama.

I did not change my cam, but I did improve cylinder head flow considerably and will be moving to a larger more modern turbine as well.