PappyDan

iTrader: (4)

just finished yesterday completing the intercooler set up.

before: at 6000 rpm's with a 2.73 pulley I would see just about 9.0 psi on hot air.
after: at 6000 rpm's with a 2.73 pulley I am seeing 6.3 psi on intercooled air.

I have gone over the whole system with soap and water, no leaks.
checked the bypass valve, holding boost and working just like it should.

is this intercooler working so good that I am seeing a pressure drop of 2.7 psi.

the intercooler core is 24" long, 12" high and 3" thick.
overall it is 31.5 X 12 X 3 and rated for 600 hp system.

need some experienced turbo people to give me some ideas on this.

fullthrottledan

iTrader: (2)

thats a big drop. I saw only 1lb drop with my cheap OBX ebay intercooler that everyone says doesnt work,lol . throw on a bigger pulley!

PappyDan

iTrader: (4)

it was not a leak, and it was not due to pressure drop from cooling down the air.
feel kind of lucky I was able to make 5 runs tonight at the track.
I shredded my internal belt tonight and came to the conclusion that size does matter,
and no the truck is not down I have already replaced the belt.

I can only blame myself for this mistake as nobody offered to tell me because I did not ask
( what size pipe should I run with a intercooler? )
I used 2.5" pipe when I should have used 3" or larger.

with the 2.5" I was able to make 6 psi when I was at WOT but at the supercharger going in to the 2.5 pipe I was making 12 psi, when the pressure hit 15 psi on the supercharger I was still only making 6 psi inside the motor and that is when the belt bit the dust.
I just rebuilt the head unit not to long ago so the belt was brand new.
I know their is some smart long haired people that are apart of the board that could work up why I was doomed to fail on the whole chalk board.

at WOT the vacuum is high.
a 2.5" pipe can only flow so much.
pressure is higher from a supercharger when the out going flow is restricted by a smaller pipe.
pressure = amount of force on my internal belt to create boost.
and 13 psi is death to the internal belt on a powerdyne. i hit 15 when i toasted mine.

now i have to start all over again with 3" pipe and connectors, and toss all of this 2.5" pipe and connectors in the trash.

i can now say if your pipe is smaller then the butterfly valve inside your throttle body then your pipe is too damn small.

live and learn.

ktmrider

Bummer on the re-tooling and belt, glad it is not putting you on the bus.
Out of curiousity, I assume the bypass valve was on the outlet side of the IC. This would make the 15psi compressor output make sense. If you had the bypass on the IC inlet side you would not have seen the manifold pressure drop unless the tap for your boost gauge was the intake. Some of the early STS turbo guys saw similar problems when installing IC's. Once they moved it after the IC things were back to normal.
Good catch, keep us informed on the progress!

AintNoHo

9 psi of restriction in that pipe? That seems like a heck of a lot. Are you sure you didn't maybe leave a rag or piece of paper in the pipe that is now stuck in the intercooler core. Just a thought before you redo all that work.

TurboGibbs

iTrader: (6)

Yeah, sounds like too drastic of a drop. Maybe I'd believe 2-3psi. I think there are some serious blockage issues going on.

dewmanshu

iTrader: (4)

shake it off! School of hard knocks is the only diploma I have!

kbracing96

iTrader: (26)

I ran 2 1/2 tubing all the way from the turbo to the intercooler and then 3" from the intercooler to the TB to keep pressure drop down. I don't think it is too restrictive at all. I guess that the nice thing about the turbo being referenced to the manifold for boost, I saw the same 7 psi before and after the intercooler install. The turbo, just makes up the difference. Good luck with it though.

TIM Z

iTrader: (12)

just 2 cents but i did not see any psi drop going intercooled and i have my wastegate referenece from the turbo and boost gauge refer. from the manifold, but im only running 5.5 psi now and will be at 10 shortly and am curious to see if i have any loss of boost. BTW sorry bout your probs Dan, hang in there!

PappyDan

iTrader: (4)

I taped the pipe for a fitting after the supercharger to help me see what was happening.
after supercharger before intercooler high pressure at wot.
after intercooler and before throttle body 6 psi of pressure.
inside intake off of vacuum line 6 psi of pressure.
slowly letting my foot off of the throttle the pressure would remain the same until vacuum was restored inside the motor.
just before vacuum took over the boost the throttle blade would be just closed enough and the by pass valve was still closed.
I would see a pressure spike jump from 6 psi to 12 psi on a 9 lb pulley
after this spike the vacuum would be restored and the bypass valve open to release the pressure back down to 0.
I did this several times until I hit 15 psi and lost the belt inside the head unit.
even after I hit 15 psi all I still saw on the motor was 6 psi of boost

this told me that the size of my pipe was too small to force feed the motors suction at wot.
I thought under pressure the 2.5 inch pipe would be sufficient to feed the motor.
the system proved me wrong.

I am going to try a few things after my vacation.
set the bypass valve in a different location.
build an air duct from the maf to the throttle body so I can run the supercharger on a flow test of the intercooler.
use 3" pipe from the intercooler to the throttle body.
then 3" pipe from the supercharger to the intercooler.