Boost or Timing

[Brian Verson]

I just upgraded to a TA49 from stock I'm running 40 lbs red stripe injectors with an SMC Alky kit , exhaust , 3 ss atr dp , v-booster and 7pos chip from caspers , adj. wastgate , adj fuel pressure reg , atr cold air kit , 160 thermostat , bla bla bla .
I had it at the track and was tring to tune it in . I found that it ran better with only 18deg of timing and 21 pounds of boost .

My question is this what will give me more , timing or boost ???

My best run was 13.57 at 105.98mph , It had NO midrange power came out of the hole hard and on the top end was great .
My best run on my stock turbo was 13.14 at 103.53mph
On street tires .

What am I doing wrong ???

 

[Dan Thompson]

Not that I can be of much help, but the questions are going to be what is the fuel pressure, O2 reading, knock reading.

Do you have a scantool?

What is the converter stall?

 

[Brian Verson]

Thanks for the reply .

My o2's are around .85 / .95 volts in first and second and in drive goes to .65 / .75 volts , TPS at wot is 4.22 volts .

Yes I do have a scan tool its a snap-on MT2500. I can tell if it is knocking but not the deg. of timing retard .
Fuel Pressure is around 34 / 35 psi. with vac. line off . and I have the alcohal injection that fattens up the mixture .

The converter is stock.

On the run when I went 106mph once it hit drive I was gone 21 psi of boost 20 deg. of timing & no knock.

Also the boost is going crazy back and forth 15 /21 /15 /21

Thanks .

 

[Orion231]

Bigger better stuff...

I didn't think there would be much in the way of tuning my new PT 51 and setup...but to start I had to reset my Minimum Air Rate(IAC, TPS) for the new chip, spring clean, then I set the turbo to "tuner" mode for boost control, you simply run one single line from wastegate to turbo, and bypass the factory wastgate, turn the boost down and it should remian calm, do you notice a funny noise unde rboost before you let off like the turbo is tryign to sneeze while boosting? It's called compressor surge, happens with bigger turbos, try that and you can set the boost and turn it up easier also. What else is it doing?

 

[ghall]

I can't be a whole lot of help either----but i can tell you that you will told to adjust your tps--need more like 4.60 at wide open throttle.

I have a Casper's chip also---i am sure you will be asked what position it is on and if it is programmed for those inj's--just trying to throw some ideas.

Geoff Hall

 

[ACME RACING]

Fuel pressure

With vacuumn off the regulator you should have 40-42 LBs of pressure. Check the O2's at wide open throttle in third gear above 4000 rpm (more load on engine) , should be .770-.820 to be safe. TPS should be set 4.50 - 4.70 at wide open. I run a Caspers Version 4.00 that has 7 settings for advancing timing, 18-28°. With 112 octane and 19 LBs boost and 24° timing i run a 109 MPH, with 28° timing i run 111 MPH. 20° i run 107 MPH.......You have to try all the settings, but be sure your fuel pressure is 40-42lb with vacuumn unpluged alan

 

[tminer]

Boost or timing? Age old question (at least since 1984 ). And guess what, opinions vary!

The best bet is probably to methodically keep trying combinations. With alky on the street you also need to be careful about timing. Since the alky only sprays basically at WOT and high boost you can have some extra timing there, but if there is also extra timing when the alky isn't flowing you can be getting some knock. Probably won't blow a head gasket, but it does take a toll. So you might come up with one timing for general street duty and another for kill.

Tom

 

[Brian Verson]

BOOST & TIMING

The people that own Buicks have got to be the best people on the planet !!!
I took all of the info given and went to work on my BB . Reset my TPS to .42 at idle and 4.56 WOT , Cleared the KAM (Keep Alive Memory) so my computer could relearn fuel delivery , and adjusted fuel pressure 40psi no vacuum . I played with timing and my alcohol . I think I've got her dialed in

Now if can just find a doctor to pry the smile off my face ???

Thanks to all that helped

 

[quickt]

Boost v/s Timing

I say as much as you can on both.

There are many articals that can help you tune your car on the www.gnttype.org. Check them out they will offer the most detailed information. When tuning with the MT2500 I used that thing for years. Make sure you put the tool in the road test mode and it will show knock retard. also when tuning by yourself you can touch the y button before decel and it will hold the last recorded frame so you can scroll and view your info on the side of the road v/s at 100 plus MPH. (Like I have never done that one).