The 454SS does it again. Little G's turn...

[Fasterthanyou]

So yeah, I'll let Matt post his times but I'll tell you now that it's faster than Little G. Not by much but it's faster.
Matt's also running without enough fuel so expect his mph to go up and ET to go down significantly when he's got the fuel flow.

[badzracing]

So yeah, I'll let Matt post his times but I'll tell you now that it's faster than Little G. Not by much but it's faster.
Matt's also running without enough fuel so expect his mph to go up and ET to go down significantly when he's got the fuel flow. Uh oh. Am I in trouble, John?

[Fasterthanyou]

So yeah, I'll let Matt post his times but I'll tell you now that it's faster than Little G. Not by much but it's faster.
Matt's also running without enough fuel so expect his mph to go up and ET to go down significantly when he's got the fuel flow. Uh oh. Am I in trouble, John?
I can promis you that you will be once his fuel starvation is corrected. As of right now, you're in the clear.

[EVIL90SS]

best run of the day

.160 r/t
1.989 60'
5.683 330
8.757 1/8
80.06 mph
11.411 1000
13.663 1/4
99.79 mph


need more fuel...and a day thats not 300 degrees and im huntin down 12s

[enRo]

best run of the day

.160 r/t
1.989 60'
5.683 330
8.757 1/8
80.06 mph
11.411 1000
13.663 1/4
99.79 mph


need more fuel...and a day thats not 300 degrees and im huntin down 12s

Thats crazy man. Congrats!

[badzracing]

So yeah, I'll let Matt post his times but I'll tell you now that it's faster than Little G. Not by much but it's faster.
Matt's also running without enough fuel so expect his mph to go up and ET to go down significantly when he's got the fuel flow. Uh oh. Am I in trouble, John?
I can promis you that you will be once his fuel starvation is corrected. As of right now, you're in the clear. I think I'm good to go for right now. Nice time Matt. We gotta get you into the high 11's and show these f-bod guys what's up. After I get my belt throwing problem "debugged" I think I'll be in that neck of the woods. On the one full pass I made without the belt popping, I went 13.64. That was half throttle shifting at 4000 ( about 4psi of boost and it's capable of 15lbs) and blowing the tires off through 1st and most of 2nd. Then I got brave, put the slicks on, mashed it to the floor and lost the belt at around the 100' mark....15.90 @ 67mph....goddamn belt!

[badzracing]

That reminds me....Get a blower, Matt. Or a little juice. :twisted:

[EVIL90SS]

yea dave...we gata show these f-bods that pickup trucks own !

[foff667]

time to update your sig matt :) great time though...sounds like theres alot more in it though

[NJSPEEDER]

congrats on teh times matt. now get a new locker!!!! lol

later
tim

[ProtekYoNutz]

:redblob: :banana: :cool: 8)

[Fasterthanyou]

There was an SRT8 (425hp 300c) there that ran a high 13 at 102mph. It only had 800miles on it so it's still in the "break in" period for that car meaning it's not putting down as much power as it would if there were 3000miles (it's a warranty thing). Considering that and let's SAY it was making 425hp, then Matt's truck is bookin :) .
TBI owns all, you will see. Think of it this way, TBI owners save $$$ to put into POWER making mods ;) . The rest just keep blowing it on purchasing a hand-ful of injectors and crappy cold air intakes that do dick when it's over 100 on the track.
There's also a very techincal reason why TBI does so well in the hotter weather. The only hint I'm giving is the reasoning power-adder guys are adding extra injectors WAY upstream :wink: .

[The Fixer]

Damn, I'm impressed. How does a truck with no weight over the rear and no posi pull a 1.9x 60'?? Very nice work!

[j0n]

psssst...post your new times in the timeslip list...sticky in the lounge

[foff667]

Damn, I'm impressed. How does a truck with no weight over the rear and no posi pull a 1.9x 60'?? Very nice work!

big sticky tires

[Squirrel]

Damn, I'm impressed. How does a truck with no weight over the rear and no posi pull a 1.9x 60'?? Very nice work!

big sticky tires
not big...****in monstrous :D

[Tru2Chevy]

Damn, I'm impressed. How does a truck with no weight over the rear and no posi pull a 1.9x 60'?? Very nice work!

29"x10"x15" Hoosier D-5's

Matt - get the fuel pressure turned up! Great runs, well worth the sunburn on my face :)

- Justin

[JL8Jeff]

Sounds like you need the vacuum reference fuel pressure regulator that automatically adjusts the pressure based on vacuum.

[Fasterthanyou]

Sounds like you need the vacuum reference fuel pressure regulator that automatically adjusts the pressure based on vacuum.
NAH. I tried that years ago and so did a few of my friends. None of us liked it. The only time you need to vac reference the pressure regulator is when the injectors see the manifold vacuum. In our case the injectors are always seeing atmosphere (above the throttle body). When you install a vac.ref FPR it helps ONLY if you don't have a good tune. As it stands Matt's got a decent tune but I can't command the injectors to stay open any longer. They're stuck open from like 3500rpm and up (static) meaning he's lean up top where he could be making some monsterous power. The only tuning we did was remove a couple degrees and add a few. Adding a few did appear to make a difference since with a hot engine he ran a better ET... lean engines need more timing... so again, he NEEDS to increase the fuel pressure if he wants to make more power. Right now it's just a torque monster when it could be a torque and horsepower monster.

[JL8Jeff]

From what I've read, the VRFPR will give a higher fuel pressure at max than any of the adjustable FPR so that's why it works better. Sounds like you guys it had it hooked up to the wrong vacuum source. But another restriction could be his fuel line. The factory fuel line is pretty small and can restrict the hp potential in the 450 hp + range which sounds about where he is.

[foff667]

i dont think he has even an adjustable fpr...either that or he just hasnt bumped it up to where it needs to be.

[Tru2Chevy]

I don't know exactly what he has, but I know that he needs to take the top of the throttle body apart to get to the fuel pressure adjustment.

<-- TBI stupid....

- Justin

[Fasterthanyou]

From what I've read, the VRFPR will give a higher fuel pressure at max than any of the adjustable FPR so that's why it works better. Sounds like you guys it had it hooked up to the wrong vacuum source. But another restriction could be his fuel line. The factory fuel line is pretty small and can restrict the hp potential in the 450 hp + range which sounds about where he is.
It won't do that, it's actually the opposite. What it does is use the "set" fuel pressure at WOT and cranking (no manifold vacuum) and then when there's vacuum it will pull DOWN the fuel pressure. So let's say we making his AFPR vac ref. Hook up the vac line and all of a sudden instead of the 12psi he's running now he'll only have 8psi. Then when he puts pedal to floor it'll go up to 12psi. The only reason to need a VRAFPR on a TBI motor is if you're running 450+hp with 2 injectors and having trouble getting it to idle (pulse widths are too small). Other than that, whoever told you it was different needs to get his facts in order because he's not a very good edjumicator :)
Also, we he doesn't have a VRFPR so we can't hook it up wrong. There is no vac ref with decent TBI regulators. The ones that are were patch fixes and were crap, I'd never use one again.
Yes, the fuel line size does become a factor. We'll be pushing it's limits with this motor but I've told Matt that from the beginning. I honestly think the best route to tuning this beast is to get a carb on it and tune that first. That way you know the power potential and with TBI, just try and match it. It's a great way of finding if you're fuel limited.

[NJSPEEDER]

matt has the DIY-AFPR on his truck. we did it back in teh day, i think it was before the manifold swap was even done. :)
if i am not mistaken matt has 80pph injectors, a set of 90pph injectors would not solve teh problem entirely at this point, but it shoudl make the tuning much easier.

later
tim

[Fasterthanyou]

matt has the DIY-AFPR on his truck. we did it back in teh day, i think it was before the manifold swap was even done. :)
if i am not mistaken matt has 80pph injectors, a set of 90pph injectors would not solve teh problem entirely at this point, but it shoudl make the tuning much easier.

later
tim
I'm 90% sure he has 90#ers if he hasn't changed them out. The early BBC's got the larger injectors because they were running at a lower fuel pressure than the later models. Example; the last couple years of the TBI's were running 15-16psi so they flowed ~45# on the 350. So "350" injectors don't mean squat, same with the BBC. The early years got the 90#, later got 80#. That's to say that the 90# were 90 @ 11.5psi and the 80 @ 11.5, higher because they used higher fuel pressure between 92-95.

[JL8Jeff]

You kind of made my point, the vrfpr gives a full 18 lbs of fuel pressure at full throttle(or lowest vacuum) and the stock fpr is only around 13 lbs and the other adjustble fpr's are around 15 lbs. So the vrfpr could be supplying more fuel than the others and give you a better idle to help pass emissions. As for the mods Tim said he already did to it, have you put a fuel pressure gauge on it to see what it's really getting at the injectors? I never installed it on my truck so I'm not sure what pressure I was getting. And I believe the 90-91 454 trucks had the 90 lb injectors so there's nowhere to upgrade to. Just a thought on getting more fuel into the engine.

[Fasterthanyou]

You kind of made my point, the vrfpr gives a full 18 lbs of fuel pressure at full throttle(or lowest vacuum) and the stock fpr is only around 13 lbs and the other adjustble fpr's are around 15 lbs. So the vrfpr could be supplying more fuel than the others and give you a better idle to help pass emissions.
:?: That makes no sense. How did I make your point and where are you coming up with the vrfpr giving 18psi? Stock is not always 13 and the adjustable's can be anywhere you want them to be, not stuck at 15!!! There are some stock regulators running 22psi, there's one on my Dad's suburban right now.
I think you need to re-read my post, you might have gotten some numbers mixed up or something.

[JL8Jeff]

OK, let me explain this the way I thought it works. I'm probably wrong so correct me if I am. The fpr "sets" the fuel pressure at a specific level. Let's say stock is 13 lbs. So your TBI is allowing 13 lbs of fuel pressure to the injectors at all times. The computer tells the injectors to stay open longer or shorter depending on the throttle position. So you now have a set limit on how much fuel it can flow based on the 13 lbs of pressure and the injector pulse width. An adjustble fpr allows you to adjust that pressure between 8-15 lbs say. So you set it at 15 lbs and obviously get more flow at WOT. The vrfpr automatically adjusts the fuel pressure from 8-18 lbs depending on the vacuum signal so WOT would be giving you 18 lbs of pressure which should be flowing more fuel. I know several people have measured the vrfpr at WOT at 18 lbs so that's where I'm getting that number. Now, is there a fuel pressure sensor somewhere in the TBI that the computer reads and can be programmed? If so, I'm not aware of it.

[Tru2Chevy]

FYI - Matt has a nice electric fuel pressure guage, however he hasn't bothered to hook it up yet....

- Justin

[Fasterthanyou]

OK, let me explain this the way I thought it works. I'm probably wrong so correct me if I am. The fpr "sets" the fuel pressure at a specific level. Let's say stock is 13 lbs. So your TBI is allowing 13 lbs of fuel pressure to the injectors at all times. The computer tells the injectors to stay open longer or shorter depending on the throttle position. So you now have a set limit on how much fuel it can flow based on the 13 lbs of pressure and the injector pulse width. An adjustble fpr allows you to adjust that pressure between 8-15 lbs say. So you set it at 15 lbs and obviously get more flow at WOT. The vrfpr automatically adjusts the fuel pressure from 8-18 lbs depending on the vacuum signal so WOT would be giving you 18 lbs of pressure which should be flowing more fuel. I know several people have measured the vrfpr at WOT at 18 lbs so that's where I'm getting that number. Now, is there a fuel pressure sensor somewhere in the TBI that the computer reads and can be programmed? If so, I'm not aware of it.
Jeff, that's not how it has to work but it is how it can work. I think it's easiest if I just tell you what I've done to my car and it might make you think twice about those crappy VRAFPRs.
I had 12psi, it wasn't enough for 330hp so I tried cranking up the fuel pressure because lucky for me, the holley fpr is adjustable. It goes up to 15psi and then anything after that causes the pressure to spike up to 50+. I was bottoming out the spring. Okay, get a larger spring, install it and I've got 28psi :) . Now here's the kicker, I can still control my idle! I don't need lower fuel pressure at idle because I've adjusted my calibration acordingly. Now when I hooked up the VR to my AFPR the fuel pressure went down at idle but my tables in my calibration looked all fubar (because the injectors don't SEE manifold vacuum so pressure differential has just changed). This is why I hate them and why nobody should ever need them if you do the tuning that is needed.
So here's the low down; stock regulator 13psi, AFPR isn't 11-15 it's more like 8-20 as a range, VRAFPR is the same as the AFPR only at idle it pulls DOWN the fuel pressure. Both the AFPR and VRAFPR will flow the same amount of horsepower supporting fuel but the VRAFPR will work best if you haven't touched the calibration, the AFPR will work best if you have.

[JL8Jeff]

Yes, I was looking at it from a point of no custom programming so the vrfpr looked like the best compromise. Did Matt see that Turbo City has the overbored 454 throttle bodys at 2-1/16" bore instead of the stock 2" bore. That could help with the extra flow he needs. He still might be maxxed out on the injectors or fuel line though.

[Fasterthanyou]

Yes, I was looking at it from a point of no custom programming so the vrfpr looked like the best compromise. Did Matt see that Turbo City has the overbored 454 throttle bodys at 2-1/16" bore instead of the stock 2" bore. That could help with the extra flow he needs. He still might be maxxed out on the injectors or fuel line though.
He shouldn't need more than the 2" TBI. That's equivelant to a 51mm EFI throttle body. Last time I checked the RamJet 502 was using a 48mm TB and had no problems :) . TBI is almost always fuel limited. When you get to about 350hp that's when you wan a 2" TBI, at about 450 the largers might help, might not. I would consider the TBI upgrade a waste when he hasn't gotten the fuel traightened out yet.

[DieselKickYoAss4Sure]

throw a ****ing carb, on it a blower in between would be nice, and a better rear god damnit all. Because as soon as he starts to hit that lucky number 12 its gonna break into a few.............hundred peices. Ill have to get the duelly running wish i was home i think i can trap at the same speeds. Conversations between my father and I have touched the surface of propain injection then ill be pulling both fronts of the ground big smily faces across the screen.
:lol:

OH AND JUST FOR ALL YOU WEIGHT NAZZIES ITS COOL AND EVERYTHING WHAT YOUR DOING BUT THIS JUST PROVES IT CAN BE DONE WITH AC. TRUCKS ****ING RULE

[foff667]

throw a ****ing carb, on it a blower in between would be nice, Â*and a better rear god damnit all. Because as soon as he starts to hit that lucky number 12 its gonna break into a few.............hundred peices. Ill have to get the duelly running wish i was home i think i can trap at the same speeds. Conversations between my father and I have touched the surface of propain injection then ill be pulling both fronts of the ground big smily faces across the screen.
:lol:

OH AND JUST FOR ALL YOU WEIGHT NAZZIES ITS COOL AND EVERYTHING WHAT YOUR DOING BUT THIS JUST PROVES IT CAN BE DONE WITH AC. TRUCKS ****ING RULE

did you take your meds today phil?

[DieselKickYoAss4Sure]

did you take your meds today phil?

no sorry i forgot