ok i have a couple of questions i will post them in seprate threads for search capabilities one is What is the effect of increasing boost with out increasing fuel delivery ?? i have just installed a 2000 6.5 with an adjustable spring loaded wastegate controller and a 6.2 manuel pump in my 85 k2500 i am told this pump is not capable of delivering enough fuel for this motor but it seems to run good only been in a day and a half though

edited this post both questions are boost related so i think one thresd is ok
has anyone tried to pin the wastegate closed and used a blowoff valve set at the max boost you want like they use on the rice burners with the fart pipe, and the shopping cart handle on the back?? :lol:

I don't know of anyone using blow off, plus in a Diesel vs gasser I think but don't know 100% that difference with way spool up goes not an effective way to regulate boost in a Diesel using a GM-X turbo.

You do need to add both fuel & boost, problem with 6.5 PCM controlled engine boost is clipped too soon, so we fool it ot TM it to sustain boost beyond what PCM is set for, sufficient fuel is available for some additional power with added boost, but you will run out which is why there are rechip & reflash programs to address this. As for mechanical 6.2 IP on a 6.5 I'm pretty confident not enough pump to feed a 6.5.

IMO with a reflash or chip electronic IP is plenty of delivery, remote mounted PMD fixes the electronic most common fail.

the truck runs really well with the 6.2 pump on it there is no computer in my truck i am running a home made turbo master truck has decent power on accell boost comes up to 10 psi on accell drops down to 5 psi crusing i don't have any clamps on the rubber hose that connects the turbo to intake if i accellerate real hard boost comes up quickiy and i can hear it leaking out the hose i think that is why it stays at 10 psi lol o and i am using a gm8 turbo

ok all clamps in place now cdr piped into intake 15 psi boost truck is a lot more powerful than the old 6.2 was. still can't figure out why the 6.2 pump is too small ? tgd how about i come by you can come for a drive tell me what you think

i have a mechanical pump that gives 300 hp worth of fuel to 8 cylinders and it doesn't care weather it's a 6.2 or a 6.5

grape what pump # 4911 ? mine is a 5502 the truck runs very well it is cranked up as high as it will go and it is a lot faster than the 6.2 was

4974 is where they start, there is one other one that is larger but also operates at higher pressure and I'm not certain of the pump number from stanadyne. My local pump shop and I researched this crap for over a year before we came up with the 4974 number.

here are some pics of my 6.5 turbo in my 85 k2500

The reason I say the 6.2 pump won't flow enough fuel for performance use is like you I ran a 6.2 pump wide open on a 6.5 and it ran well, at least I thought so until I put on a 4911 6.5 pump, WOW and then I turned it all the way up YE HA. But you engine is a lot safer with the 6.2 pump, because I cracked a piston after 2 weeks with a 4911 pump:( . In my 18:1 version though, I still could have used some more fuel, although if I nailed it before the turbo spooled up I could lay a very healthy smoke screen):h .

all i want out of it is something that has decent power and good reliability this setup compared to the 6.2 it replaced seemes to be the ticket my 6.2 had about 300 lbs compression across the board and used about 8 litres of oil a week

I like your truck 69camarox, you have all the room for a "big" IC. 15 psi will crack those pistons, :D

To answer the original question, What happens when you add more boost and no fuel increase to match.
The way I understand it, you can't run it too lean. The more air in the more efficient your burn will be. All that a higher capacity pump will do is waste more fuel to take you to the same spot, although perhaphs faster.

This is one of the reasons I havn't gotten a chip for my '94. It burns enough fuel alraedy.

the 15 psi wast the highest i saw i cranked it back so it will peak at 12 psi wot runs around 6 psi cruisin 60-70 mph had it around 90 mph and still climbing but all the other cars were getting in the way):h i aorked out the milage on the first tank of fuel and i am getting 19 mpg "imperial gallon i am in canada" yea QM i can fit an ic in there about the same size as the rad :lol: if i could find one cheap i only have about $600 in the engine swap don't want to spend more money on an ic than i did on the engine :muahaha:oh and i put on a new fender today that old one was making me sick every time i looked at the truck