3" down pipe - 4" exhaust straight pipe - Mandrel x-over - Re-flashed - Pyro Post Turbo.

60 MPH - 7 psi - 420F EGT

70 MPH - 10 psi - 450F EGT

80 MPH - 11 psi - 540F EGT

Can anyone give a comparison to these numbers with different exhaust sizes and configurations, i'm curious to see if the 4" pipe helps or is more for bragging rights of mine is bigger than yours?

These were made with ambient temps @ -5C or 23F on a flat road for a couple of miles minimum at each speed.

Seems i'm having trouble with boost now - can't get it over 14 psi for some reason.:cool:

Those seem quite low to me for the boost you're making. . .

Hey CR you running per or post turbo on that EGT if post how far down the pipe is your thermocouple

What kind of weight you figger on that truck with those numbers, looks a little low to me also, but IIRC it's pretty cold up in them parts rite now which would make the numbers somewhat lower.

3... maybe 4" below the clamp on the downpipe (post turbo), weight...hmmmm... heavyyyyy..... Tool box as per avatar loaded with a couple hundred pounds of junk for work, fuel tank below box, holds around 35 US gallons. Running around 0C or 32F during the day right now.

Okay 32 F splains why your EGT isn't that high, and why hoppin it up to 17psi boost hasn't caused fuel clip yet from, hi IAT, keep an eye on it when ambient starts getting warm again. From what I've read on other forums not that much difference between 3.5" and 4" pipe, noticeable though between 3 & 4, and marked difference between stock 2.5 and anything bigger than that.

I have 3 inch down pipe and 3 inch exhaust. my temps are running bit different.

at 70 mph it take 6 psi boost and running bit over 500 degrees on level ground in the 30-35 OAT range. I notice a nice drop in temps and increase in boost when I had a magical event happen when my soot trap disappeared! (don't know how that happened) there has been alien sightings around here tho!

The '94 has been running much cooler since the one piston rebuild. going 70mph unloaded at ambient of 65* F, boost 10 psi+, I get 600*F pyro temp in the exhaust manifold, 3" straight pipe.

Thats pretty good and your pre-turbo.

70MPH 2200rpm 4psi 380EGT

3 passengers, full tank of diesel (2 adult, 1 toddler, 1 doberman:D )

Post turbo, so I guess 580 or so EGT

Might be lower than that in a bit. I'm going to put a spearco IC on this truck for awhile.

Bobt, wait for a hill or large overpass and lay into it 'till the boost comes up and hold it there till you make the top. That way you can maitain steady speed for the passengers and watch the pyro climb.

I haven't corrected my speedometer on the blue suburban yet, so I have to guess at about 75 mph, but 2500 rpm nets 9 psi of cruising boost at 600-650F pre-turbo. Currently, I don't have the fuel up past 59 mm^3, so I'm really looking forward to a bigger IP and injectors.

Are you going to try turning up your old pump first?

I probably will, but for experimenting purposes only. I really need some higher pressure injectors to take advantage of any more fuel, since any increased setting on my current configuration will likely gain more smoke than power. My front D60 is the primary money-sucker right now, so it will be a little while before I tinker with hard components on the engine again, though I have found some room in the budget to build a better cold-air intake with a Dmax AFE.:D

I'm one front axle short and the dana 60F is my axle of choice. Do you have anykind of skid plate between the truck and the front axle?

Negative, Ghostrider. There's enough overhang on the front of the 85 that a skid plate would just crash and grind against any rock shorter than the bumper. I can, and have, placed my front wheels against a rock and just climbed up and over where a skid plate would have, in the very least, interfered with that motion.

So no, functional front skid plates on solid axled trucks...aren't that functional; more for show IMO.

That said, I may experiment with a small air dam that just covers the area between the front crossmember and the harmonic balancer. I want to see if it makes an impact on my engine cooling.

I will be pulling my 28' 5th wheel 200 miles tonight or tomorrow, will try to update then.
I did a 0 - 60 yesterday but only used part throttle just down on the peddle to where it gets a little stiffer and still got 13 secs, whats up with that??

3" down pipe - 4" exhaust straight pipe - Mandrel x-over - Re-flashed - Pyro Post Turbo.

Heres the update of my trip home pulling my 5th wheel trailer

60 MPH - Boost 11 psi - 675 EGT's - 2000 rpm

70 MPH - Boost 12-13 psi - 800 EGT's - 2300 rpm

Total weight of truck and trailer = 15,212 lbs (stopped at a scale)

I couldn't find a stretch to get up to 80 MPH but the truck would have done it on the flats no problem, we had 40 to 50 MPH winds today but most pulling the wind was from the side.

Hitting the hills doing 60-65 or so at the bottom the EGT's climbed fast to 1200F and were creaping past so i took my foot out of it to let EGT's come down, also the boost was fluctuating constantly from 13-15 psi when pulling hard once EGT's hit 900+, i'm not sure why the boost was doing that, PCM must not have liked the IAT's it was seeing?? Clutch fan never kicked in once all the way home. Ambient temps around 45F

Comments??

3" down pipe - 4" exhaust straight pipe - Mandrel x-over - Re-flashed - Pyro Post Turbo.

Heres the update of my trip home pulling my 5th wheel trailer

60 MPH - Boost 11 psi - 675 EGT's - 2000 rpm

70 MPH - Boost 12-13 psi - 800 EGT's - 2300 rpm

Total weight of truck and trailer = 15,212 lbs (stopped at a scale)

I couldn't find a stretch to get up to 80 MPH but the truck would have done it on the flats no problem, we had 40 to 50 MPH winds today but most pulling the wind was from the side.

Hitting the hills doing 60-65 or so at the bottom the EGT's climbed fast to 1200F and were creaping past so i took my foot out of it to let EGT's come down, also the boost was fluctuating constantly from 13-15 psi when pulling hard once EGT's hit 900+, i'm not sure why the boost was doing that, PCM must not have liked the IAT's it was seeing?? Clutch fan never kicked in once all the way home. Ambient temps around 45F

Comments??


Comments anyone?