HELP!!! do these # sound right 2.80 4# lower

[icu812]

well I just got back from the dyno and my new #'s are as follows
max HP was 482.4 and TQ was 509.4 with my new set-up (2.80 / 4# lower). boost was 17.8 psi
till around 4500 rpm then it started dropping off. 14# at 6000 i believe
we did the boost by-pass mod manually then through the tune no change these #'s seem low (correct me if I'm wrong ) with my old setup I made 501hp/470 tq @ 12.5 psi boost w/ just a 2.93 & stock lower and a port.
would putting the 2.93 back on give me the 520-520 that I see with all other combos or what could be wrong? weather was great in the 60's
belt slip is not the issue as we thought, so we sprayed some VHT on and only gained .2#
total timing was 21* and a 11 A/F BAP set to 40%
any insight would help as I'm lost to what it might be.

 

[NotoriousGT350]

When i dynoed mine earlier this year with a IV port and same pulley combo, I had seen boost up to 18-18.5psi, then drop to 14-15 after 5000rpms. I'm getting belt slip and my a/f ratio on my Wide Band has been going from 11.6 a/f to 10.3 right around 5000rpms and up. I'm seriously thinking about just switching to a 2.93 upper with 4-piece BF idler setup. I'm tired of losing boost and power up top where I need it.

My numbers were 490rwhp/522rwtq. I have 60lb injectors and BAP set to 0%. I know I have a lot more in it. Let me know how things turn out.

J.R.

 

[Antex]

my a/f ratio on my Wide Band has been going from 11.6 a/f to 10.3 right around 5000rpms and up.

My numbers were 490rwhp/522rwtq. I have 60lb injectors and BAP set to 0%. I know I have a lot more in it. Let me know how things turn out.

J.R.

I see the problem - you're running rich at the top end - 10.3. Not sure what type of octane you're set up for. I've got 93 here and on my street tune A/F at the top end is 11.5. Bap is set at 40%.

 

[NotoriousGT350]

I'm actually setup for 93* octane. I have the BF 4 piece setup and have only added 2 idlers since I'm running a Gates 080780 belt and now my boost doesn't go up to 18psi then drop to 14psi. Today I made a couple of passes and I had seen 16psi and holding steady with drop to 14.5-15 around 5500rpms. I'm going to go ahead and add the other 2 idlers, make a few more runs and see where my a/f ratio is at b/c it still drops into the 10s pig rich. I put the BAP a 0% since I have 60lbers.

Are you still on stock injectors Antex?

I'm also trying to figure out the Predator with the Short term and Long Term fuel tables and figuring if the tune is pulling fuel out where I need it or adding it. My Maf counts around 5000-6200 are from 810-864 going up and down with the MAF.ia set on 2. Lot of datalogging I've been doing.

 

[DSG2003]

Torque looks a little low. I don't have a port and I have to run 91 octane here in CA and I put 508TQ.

 

[ricksterman]

I have the same combo with a Stage 4 port, and heat soaked I get 500/525 (corrected). You are running a Gates belt, although there are numerous opinions about this subject matter, if you can't find anything else wrong try a Gaterback. I have both, but I run the Gaterback, it seems to slip a little less, but there is a lot more belt dust. The boost drop is certainly in the air temperature, not necessarily belt slip, remember that with this combo you are spinning the living hell out of the Eaton. At the track bags of ice for both the Eaton and the LFP tank are a must.

Datalogging the SHRTF trims is only for comparison. The 1 V sensors are not accurate when you get away from 14.7 for gas. Wideband is the way to go for forced induction. Running a little rich is ok, better that than BOOM!

 

[95YellowGTBeast]

:shrug: i made good numbers with a 2.8 and 4lb lower there in my sig...

 

[Antex]

I put the BAP a 0% since I have 60lbers.

Are you still on stock injectors Antex?

I'm also trying to figure out the Predator with the Short term and Long Term fuel tables and figuring if the tune is pulling fuel out where I need it or adding it. My Maf counts around 5000-6200 are from 810-864 going up and down with the MAF.ia set on 2. Lot of datalogging I've been doing.

I've got the 60lb injectors and when my tuner was data logging some of my street pulls he also tested the bap and found it was giving the best voltage at 40. I'm not a tuner but the BAP doesn't control fuel just the voltage from my understanding.

 

[ChicagoMike]

Bap at 0% .. bad idea. Injectors are the doorway to combustion. So it's set at 0%, the fuel pumps cannot possibly keep up with 60 lb injectors at full boost.

Boost a pump = increases fuel output of the pumps

Injectors = headroom for more fuel if you were to increase the pump voltage or the pump size

 

[NotoriousGT350]

Makes sense now :read: Guess I'll turn it up to around 20-30%, make some passes once I get my iders on and rethread an idler hole(posted on Terminator Talk), and put on a slightly larger belt 080785 to check everything.

If I still get my a/f reading from 11.6 then dropping to 10.3 at 5000rpms, then it has to be in the tune. I just want to get everything just right before I take it out to the track again which might be a while since I'm saving up for other things, baby *cough,*cough, fixing up the 89' GT, etc.

 

[BADASS03SVT]

same boat here...2.93 / 6# and i get 17psi then drop to 13 at 6k rpms. the guys with 2.93 / 4's get to 16.5-17 and its stays up there....better curve and the hp will rise more which will net a higher peak. I'm switching this week

 

[NotoriousGT350]

same boat here...2.93 / 6# and i get 17psi then drop to 13 at 6k rpms. the guys with 2.93 / 4's get to 16.5-17 and its stays up there....better curve and the hp will rise more which will net a higher peak. I'm switching this week

Let me know how you like your new setup once you get the #4 lower on and the results :thumbsup:

 

[icu812]

just got my 2.93 in today I'll be switching it out in the morn then see how she feels

 

[lthlsnake]

why is the 2.93 with 4lower better than the 2.8 and 4lower? sorry to get off the subject

 

[BADASS03SVT]

why is the 2.93 with 4lower better than the 2.8 and 4lower? sorry to get off the subject

i thin its spinning the blower too much in the higher rpms therefore making your curve drop instead of staying steady or going up.

 

[lthlsnake]

i thin its spinning the blower too much in the higher rpms therefore making your curve drop instead of staying steady or going up.

so your saying there is more power with a 2.93 than a 2.8 with a 4lower?

 

[BADASS03SVT]

so your saying there is more power with a 2.93 than a 2.8 with a 4lower?

from what I have seen...yes. if you look at a 2.93/4# dyno graph...they pull all the way up to 6k rpms where peak hp is made. my peak hp is at 5600 rpms. I'm dropping mine down to a 4# or 3.1 upper to raise it up 500rpms next week. going to test 2.93/6#, 2.93/4# and 3.1/6# for the best results.

 

[lthlsnake]

from what I have seen...yes. if you look at a 2.93/4# dyno graph...they pull all the way up to 6k rpms where peak hp is made. my peak hp is at 5600 rpms. I'm dropping mine down to a 4# or 3.1 upper to raise it up 500rpms next week. going to test 2.93/6#, 2.93/4# and 3.1/6# for the best results.

well keep in touch. im curious now lol

 

[BADASS03SVT]

well keep in touch. im curious now lol

plus..people with a 2.93/4# make the sam epower as people w/ a 2.93/6# and it spins at a lil slower rpm thus a lil less heat which i think helps too

 

[lthlsnake]

yeah i know my 2.8 and 4lower is spinning it alot causing alot of heat prolly