In my continued quest to find more power I decided to add a little more boost,
AMOF A big WOO HOO and Thanks to Mark of LFP
FINALLY someone makes A REAL 10lb ring to fit the interchangable lower hubs,
THANKS MARK, and thanks for the overnight shipping too

So we put it on last night (10-1/4" od) along with the 2.7 Upper.
Sal Dyno'd it with Mark (St Lou) sitting in the Pass seat watching the Boost Gauge, CAN YOU SAY 24 LBS OF BOOST
BUT unfortunately we lost power, A LOT of power, like 20HP and massive Torque.

Now if thats not bad enough, as Sal made a second and third pull it continued to drop more and more, like another 10HP loss, SOB was down to like 420 HP
AND the IAT temps were through the roof, like 150+, (usually they are more like 120). He let it sit and cool a while and we gained back some, but it was still A GOOD 20HP down from my normal #'s

Bottom line we have once again found the limits of something on my truck,
and that is a 112 Cu In Supercharger (on stock heads and cams) CAN NOT and WILL NOT take 24 lbs of Boost. I will keep the 10lb lower and try to swap the 2.7 Upper out for the 3.0 Upper I have (If I can find it, been missing for weeks @$(%(@$@%$@$%)@$%)@$

OK who can do some math

Had 9-7/8" od + 2.7" upper
What would 10-1/4" od and 2.9 / 3.0 = ????
WILL IT BE WHAT I HAD BEFORE
MORE
LESS
?

Thanks.....

 

Rob,
I have exactly what you are looking for. An Excel spreadsheet that will give you hours of fun. Just pm me your email address and I will send it over.

TB

PS: My spreadsheet says that you are totally insane...

 

I hope your not paying for all this dyno time. You could have bought a KB by now and be done. HaHaHa

Good luck with whatever it is you will be trying next though.

 

Not a bash in anyway, but why do you guys keep throwing boost at and making dyno pulls with this thing if you can't get it to run 100%>??? I am just curious about that. I think a vehicle should be 100% perfect before any WOT attempts are made. You have a decent amount of $$$ into that motor and whole lot to lose. I just don't understand. -Mat-

 

Any questions?

















LOL




.

 

Mat

The truck runs PERFECT on the dyno or at WOT
The ONLY ISSUE left is the bogging issue and that only shows it's face SOMETIMES, and ALWAYS when giving it gas from idle, hence the reason we couldnt race it "YET"

We had it up to 470/615 STD last week and I was quite happy with that,
so I figured why not try a little more pulley. Charles, Sal, Me, (we all agreed) that just maybe a tiny bit more Boost would help make some more power, so we tried it. The Motor is perfect, the tune is perfect, and the truck is a Beast on the Street. There is no reason I cant continue my quest on adding mods and power "inbetween searching for the Gremlin" BTW, I ever catch the MF Gremlin down a dark alley, IT'S MINE

Last night just proved one thing, THERE IS A LIMIT TO WHAT IT WILL TAKE VIA BOOST POWER, and we found it. SOME may find the info helpful so I'm posting it. Now I'll install the larger Upper, end the slipping belt issue due to the small 2.7 upper pulley, and get my power back.

Then n20 Dyno's will begin
SOMEWHERE INBETWEEN SAL WILL FIND THE GREMLIN

Thanks TB

rob3832@optonline.net

EDIT
LMMFAO @Odin's Wrath, SEE HE UNDERSTANDS

 

rob, sometimes you just got to say WTF!!!!!

my truck had some issues as well, i threw a bounch of nitrous at it and burned the little f'ing gremlin right out of it to the tune of 11.05 @125mph

 

I WILL TRY THAT
THANKS

AND WOO HOO CONGRATS BRO, SMOOOOOOOOOOOOOKING ET

Holy another 10sec L

 

Hey Rob,
Guess what?

We swapped the 8.62 Lower for a 9.00 and I lost 20 HP and 30 TQ.
The street tune was fine, but the race tune took a beating.
Sound familiar?


FF

 

8.62
9.00
What the hell is that like a 1lb Pulley FF
OR SOMETHING
The 3 lower pulleys I currently have have 9-1/8", 9-7/8" and 10-1/4" od
AND I AINT BUYING ANYMORE (I already sold the other two I had

And I just spent the entire day looking for my 2.9 / 3.0 Upper Mag Pulley
and it's gone &*@^#$(@&$#()@$#^$@($^@$()@%$
I know for a fact it was in my truck, I ripped it apart at Sals last night
and it's not there. I catch any of you SOB's with my Pulley AND IT'S ON
While Sal has it we'll try a few combo's and see what happens ???
THANKS

 

Which nitrous kit was this with?

 

Put the ported Eaton back on, sell the MP, and put that money toward heads/cams. Right now that blower is doing nothing for you besides sounding louder. Good luck with whatever you decide.

-Mark

 

The issue is weak stock valve springs. “Master-of-Pain” reported in another post somewhere he picked up 36.5hp after switching to aftermarket springs and he was running nowhere near the boost Rob is. He also reported duplicating my test that showed stock valve springs allow the intake valve to open at only 18-psi manifold pressure. Can you imagine what the valves are doing at 24-psi? Higher boost will raise hp at lower rpm but once the engine gets to 4700 rpm the valves begin to float at boost pressures above 17-psi or so and the higher the boost the more they will float and the more power you will loose at the top end. Once the intake valves begin to float the engine looses volumetric efficiency so the boost pressure goes even higher. The thing is valve springs are cheap and you can change them out in 4 or 5 hours.

Charles

 

Rob started out building a solid short block that he could spray and you have him bolting on 10 lb lowers with 150 degree IAT2's. Maybe it is time to let Rob get back to his original goals instead of the solution of the week?

 

8.62 (measuring the ribs, not the lip) is my 4 pound Metco.
9.00 (rib) is the same as your 9-1/8. (6 pounder)

BTW, Sal: Thanks for the 2.9 upper....

FF