top speed since intercooler

[rbrettctd]

Before the intercooler, I could easily wrap around my speedo. Well, Id have to let off the throttle a couple times on the way there for temps, but pushing 40lbs of boost I could easily run up to 110-120 in no time. Well for the first time since the intercooler i was on my favorite open stretch of road and opened it up. Ran harder than ever straight to 98 without letting out of it, 32-33lbs boost, 1250*, and 98 was all I could get. Speedo would drop back down when I let off immediately so I know the speedo wasnt pegged. Any clue as to why its doing this? I dont need to go faster, just curious. I was still pushing a good 28-30lbs of boost and am sure I wasnt defueling, cause its a 3.07 getrag combo in 5th.

[GLHS]

Have you checked for pedal/linkage travel?
I have done testing with and without the intercooler and it varies only by 3-4 psi.

[burnt_servo]

is it possible that the lower bost presure was causing the fuel pin to not be pushed down as far , thus pushing less fuel into the engine ?

[dpuckett]

No, the AFC pin is bottomed by 10psi.

How many RPMS were you turning? You may have just hit the wall, aerodynamically speaking, running out of fuel/ power to go any faster, but then again, if you went 120 before the IC, you should do so now, too. Check for boost leaks. There are instructions on this site to do that.

Dropping that much boost with the intercooler doesnt surprise me- the cooler air wont have as much pressure, plus he is closer to the turbo's efficiency range, further cooling the air.

At 3000rpm, I came up with 116mph at 3000 rpm, with a 235/85-16 tire (654 revs/mi).

Daniel

[rbrettctd]

Not sure of rpms but ya Ive been atleast 110 in it before. Ive checked for leaks several times. had a leak right after the install, and it was the boost gauge fitting. I fixed that one. it pulls super hard to 98 and then hits that wall hard.

[dpuckett]

It would be one heckuva coincidence, but have you checked your lift pump output pressure? Other symptoms would be a lower idle, and harder starting when facing uphill. For that matter, a clogged filter will do the same thing.

DP

[rbrettctd]

Hmmmm...This is also since my new stage2 fuel pin. One thing I noticed when I pulled the old pin was a bunch of crud built up on it. Fuel filter is getting changed when I pull it in the shop and have a chance in a few weeks (the truck is parked a lot anyways). Also, it doesnt start hard or anything, but Im sure its time for fuel pusher. I have one bought, just have to pick it up. Thanks.

[dodgetkboy78]

It would be one heckuva coincidence, but have you checked your lift pump output pressure? Other symptoms would be a lower idle, and harder starting when facing uphill. For that matter, a clogged filter will do the same thing.

DP

You know, my truck is starting to idle lower facing uphill, and rev a bit when you stop fast.....................