Need idea's to help correct problem. Have searched several site's but to limited success.
- Problem is boost at starting line is only 5.3 lbs. would like to see 10 plus. On recent trip to local track, sixty foot times of 1.57 - 1.59.
- Street and Strip car spec's:

-Twin T-4 62mm turbos
-Large air to air intercooler
-AMS-1000 controller
-347 cu. in. boss b
-AFR 205 heads
-Hyd. roller cam 242/242 at .050 LS 116 Lift .585/.577 6800 rpm max.
-1.6 rockers
-victor jr. intake w/83 lbs injectors
-Big Stuff 3 cpu
-PA c-4 w/brake
-PTC 9.5 convertor
-8.8 rear w/3.55 gears
-weight w/driver 3400 lbs.
Thanks in advance !

 

What A/R's on the hotside of the turbos ?
When PSI do you start pulling timing, and what fuel ?
At 5.3 psi, are you waste gates still shut, or have they started to crack already ?

 

1) Hot side is a/r of .68
2) start to pull timing at 5 PSI --- 5psi = 32 / 7psi = 30 / 9psi = 28
3) Using Track teck 114 octang

* not using bs3 starting line timing table - should I ?

 

add more timing!!! trust me! LOL!

 

Yep!! If ECU has some type of launch control ?? While clutch is engaged and rpm, waiting at the tree ..
Some retard and extra fuel on 2 step .. Agreed with advance till boost arrives but to spool a turbo without load !!
Some anti lag is required... It will POP like hell and not good on exhaust .. Can really only be done with catless exhaust..
I cannot see your compression ?? If under 8.8 to 1 the transition from N/A to boost is large...
Does it seem to fall on its face till you hook third gear ??
Strange as it seems ?? Taller final drive may help ...

 

what is your a/f ratio @ said 5.3lbs. ?

 

Hey bud, we have somewhat the same setup, i run a larger cam and an AOD. But same basic principal. Some things i have done to get mine going. Don't run the car too fat on brake, i keep my A/F at 13.0 on the brake and i keep my timing at 34* until 5psi. You can add more timing, but only do it in 1* steps. One other thing i found that helps to get the turbos going is to footbrake the car into the first and second beam and then engage the trans brake and mash it. I am guessing you roll into the second beam at an idle and then hit the t-brake and mash it? I was doing the same thing and footbraking helped some. Also make sure your gate is staying closed, it may be opening too early bleeding some boost off. Also, how tight is the converter?

How low is your compression? I had some low ass compression and the car did not want to come up on the converter, i recently bumped it by a point to around 8.8-8.9 and helped a TON. Good luck with it man.

Anthony

 

The A/F At 5 lbs of boost is about 12.5.

The compression is 9 to 1.

The Troque converter was just restalled but my be to loose.

Thanks

 

What rpms are you launching at ? Are you using a 2 step rev limiter while on the trans brake ?

David

 

co2 on the gate???

 

What's the lauch psi at on the ams? What rpm on the transbrake?

 

I have tried launching at 3500 / 3800 / 4000 / 4400 . On the trans brake it will rise to 5 lbs very quickly 1-2 seconds.
I can not build more boost staying on the two step, (tried 7 seconds on two step). The log show a steady state after reaching 5.3 lbs.

I have the ams set at one step only at 17 lbs. ,this was for initial testing .

I do have co2 on the ams and it is working.

Have not had a chance to try idea's in this thread, will go to track this weekend if not raining.

Thanks

 

For some reason your wastegates are opening it sounds like. 3800 should be enough rpm to get you at least 8#-10# on the 2 step.

I'm not sure how familer you are with the ams-1000 but go to the options menu and look under launch boost this is the psi I'm refering to. Down track with the programed 17# what do you get for actual boost?

 

Thanks for the help . AMS Launch was wired into transbrake button. Thought we were not using launch fuction. First time with ams-1000.

Boost was waste gate springs only. Now will try this weekend at track to see how much boost at launch. Thanks nailed the problem on the head.