CHEVRACER83

Okk I have built 88-89 Tpi motors... as a matter of fact with building so many from the ground up L98 Tuned port motors.... But the discussion on your post says you have a 98 cpi setup.

I have a 98 K1500 Z71....

I had a magnacharged 5.7L..... eventually i killed it once i got gm hot cam....

Then i went to a gmpp crate 383. with the cam it has come with, it is running great.. I did find out that with the hot cammed 350... i melted 3 poppet injectors... And g.m. has a setup for mpfi you can have installed at the dealer.... It is not cheap, but it supplies more tahn enough fuel for the 383 w/magnacharger. when i first had it at stock pulley size it only sees about max 5-5.5 psi.

Now you never mentioned how hot 383 this is.... Is the cam mild? low overlap design to keep from losing boost out exhaust??

Also you mentioned tuning by fast. when you mention driving it you say the whipple is off... well have you driven it with the whipple installed???

Maybe they tuned it and changed all of the tables so taht it is already setup to try to compensate for the crappy poppet injectors....

If its running dead rich, the tune has to be bad, either that or check to make sure your vaccum reference is bringing down teh pressure at the injector..... if it is not bringing it down you are shooting a full 60-80 psi at the injector, which is far too much.

I have had the 383 in mine for over 2 years now, and it runs great with no check engine light or anything. please either post a lil more info, or pm me, and ill see what i can help you with... i think it could be an easy fix.

1fastmofo

iTrader: (3)

cam is a comp lobe seperation is 113 duration @ .006 276/288 lift is 502/520 dur. @ .050 is 224/236 thats w 1.50 ratio rockers i have 1.6;s i called comp along time ago and i wana say thy told me that the 502/520 changed to like 550? something like that.

I ran the truck at first w no charger cause fast said they could only tune it for what i had at the moment and it barely made it. he said he set the peramiters to max and was unsure it if was enough, but running at an idle you could smell fuel at the rear of the truck, did not really road test it though something was wrong, did not want to wash the rings out being that the motor was brand new.

So i installed the charger and it will not make any boost. when you nail it on the road you can hear the whipple but she falls on her face.

When it has been sitting it almosts acts as if its carbed, i have to turn the key off over and over and keep trying to get it to start, wont just fire up. i checked and it has 65-70psi at the line and i also installed a higher gph holley in tank pump, i know that the fuel pump can make enough cause when i had the proflow on it i keep bumping the pressure up with an holley adj. fuel pressure reg. (26lbs hr injectors, thats how they said get more fuel) anyway keep bumping it up and blew a hole in rubber fuel pressure line so it was alota pressure

Whipple claims that their charger will not support the horsepower that my motor should be displacing

I have considered switching to a turbo setup but i am still faced with the limitations of the cpi which fast claims to be 70hp over stock.

I called magnachargers and they said that they have a kit they are currently developing but that it is going to be well over 6800.00, it involves changin the timing chain cover, no wiring is provided nor the injector bungs, and of course tuning. with those kind of prices i might be better off pulling my motor and going with a lsx series engine.

Which i would rather not do just yet but i hate seeing my truck sit due to not wanting to have to tear my motor back down.

thanks in advance

1fastmofo

iTrader: (3)

ne things guys? what should i do

CHEVRACER83

THIS IS REALLY STRANGE THE FACT THAT YOU ARE MAKING NO BOOST WORRIES ME... ARE YOU SURE YOU ARE NOT MAKING BOOST? YOU HAVE A GUAGE.. I KNOW IT MAY SEEM STUPID... BUT DID YOU HOOK IT TO MANIFOLD REFERENCE? OR BEFORE THROTTLE BODY??

i WILL TELL YOU RIGHT NOW TAHT CAM IS A LIL HOT FOR WHAT YOU HAVE.... BUT FAST IS FULL OF IT... WE RAN OURS WITH MAGGIE ON CPI FOR YEARS BEFORE CHANGING. MUCH BETTER WITH MPFI.

I GUARANTEE YOU ARE RUNNING DEAD *** RICH IF THEY MAXED IT OUT.... TAHT IS WAY TOO MUCH....

YOU NEED A RELIABLE TUNER TO START OFF WITH..... FOR THEM TO JUST MAX EVERYTHING OUT... MEANS THEY DID NOO WORK TO FIGURE OUT WHAT YOU ACTUALLY NEEDED.

UNFORTUNATELY STUPIDITY AND MISINFORMATION RUNS RAMPANT IN THE CUSTOM CAR WORLD. YOU DONT HAVE TO HAVE A BRAIN TO TUNE PCMS.... YOU DONT HAVE TO DO IT RIGHT EITHER.....

GET A PROPER TUNE, AND GO FROM THERE... GET THE THING RUNNING RIGHT FIRST THEN WORRY ABOUT THE BOOST ISSUE.... BECAUSE IF IT IS RUNING CRAPY TO START WITH ADDING THE WHIP IS JUST GONNA MAKE IT WORSE....


BTW THE MAGGIE 5.7 KIT MAKES 5 PSI ON MY 383 GM CRATE W/ 431/451 WITH 1.5 ROCKERS ON STOCK PULLEY

1fastmofo

iTrader: (3)

yea i gotta bost guage in jumps up to 0 but nothing over, while running it on the other side of the guage which indicates vaccume, whipple told me how to test the fmu and both ways they told me to test it my fuel pressure increased, they also told me that it could not support my motor that i opened it up to breath too much.

i forgot to mention my etec 200's were 64cc's and i had em decked to 58cc's pistons are -17cc dish, what compression ratio am i at?

1fastmofo

iTrader: (3)

what is a turbo that would be large enough to support what i have. I am thinking of going to the edelbrock 3507 system again and then turbocharging that. should i go for one or two whats the advantages/disadvantages of each.

CHEVRACER83

OK the line taht goes to your gauge..... it sounds like its hooked up wrong..... magnacharger had me hookup a gauge to the tb elbow, and what taht did was under full throtle would show 0.

I sound up hooking up a reducer to the big nipple on the drivers side rear of the manifold. try hooking up there to make sure you are getting boost.

1fastmofo

iTrader: (3)

well i hooked it back to the same location that i had it before right where the elbow goes into the intake. This is where the instructions said hook it and i made boost there. It was a nice improvement over stock, went from lugging off the start with 23 inch rims to putting them up in smoke. I had a hypetech programmer on the truck and was coming down a straigh away it hit at least 9lbs (thats what the old lady saw it at) then the check gauges light came on make a long story short it hydrolocked and there was minimal detonation(edges of a few pistons were detured and when i pulled the pistons out a few of the pistons ring divider fell off. All peices were accounted for. So what better time to stroke it and change the heads. Ever since then it has not made boost. I have talked with whipple repeatidly and they have told me that several guys have tried to make the 1.3l support a 383 and they were unsucessful unless overreving the charger. I just soon go another route then setup the whipple to support or attempt to support my engine. Does that make any sence on where i am at or where i have been? Wish some of you guys were a little closer.

CHEVRACER83

I Wish I Was Too... Because You Should Be Making Some Boost... Even If Its Less Boost You Should Have Something....