mhuppertz

29 psi before the cone bomb, 34 psi after. I only see this boost in 3rd, 4th, and sometimes 5th. These are thin air numbers. I'd hate to see my boost at sea level or in humid air! The drag racers around here tell me the air is so dry that they factor for 10,000 ft most of the time!

edwinsmith

I just installed my boost controller and if I screw it down tight the boost pegs my 0-35 psi gauge. I backed it down to 34 psi.

Mine is a WH1C. 12 cm WG exhaust housing and a MAP enhanced compressor.

Edwin

Boatnik

ANd I thought I was doing all right. My mods are in my sig except I polished the inlet horn to the turbo and radiused the edges to smooth the air flow. I am seeing 20 pounds in an empty truck and 25 pounds pulling the boat. Time to tweak up the fuel screw some more!

edwinsmith

What size turbo exhaust housing do you have. 91-92.5 years had a 21 cm which is a dog. More fuel will make more boost but also higher EGT's.

[edit] OOPS! I finally saw in your sig you got a 16 cm.

Edwin

highwayrepair

Hey guys, Ive been reading the boards for a while now, but finally decided to join and start posting. I have a stock truck with the banks "stinger plus" setup on it, My boost never goes above 20, should i be worried, i thought my truck seemed to run great, until i read your guys' stock boost #'s.


Branden

edwinsmith

Welcome! Please go fill out your sig so we know what you have. If you have the VE inj pump you can turn it up to get more fuel and then more boost because of more heat. If you have a wastegate you could probably benefit from a boost controller.

Edwin

Underpsi

These are not stock numbers! Under 20psi for a stock truck is nothing to worry about, they are usually around 16 stock.

6Lpowerstroke

well last time i had it on the road i was getting like 18 maxed it at 22. and i want more!!!!!!!!

Bushy

I'm gonna throw my hat onto DieselMachine's numbers....the efficiency map on the H1's is at best 22-23psi....beyond that and you're pushing to hard and the boost is not doing you any good.
The "newer" HX35's (that came on the second gen trucks) have a 'map' slightly higher when in stock condtion...about 26-27psi as I recall....
When modified the map is extended upwards to 35 psi (+or-). This is the range that alot of us guys should be running.....
This map improvement is the very reason we go with modified turbo's like the PDR HX35 or the HTT kits...we want to increase the effective efficiency range of the turbo not only to achieve higher boost pressures but achieve them more efficiently.
Remember, the smaller the exhaust housing the more it becomes critical to watch your overall boost numbers....running, say, 40psi boost using a modified '35 and a 12cm housing is not as desireable as 40psi with say, a 14cm or 16cm housing because you're keeping your drive pressures under better control with the larger exhaust housing. I think it's a bit of a missunderstanding when it comes to the larger housings as well....
You can make a 16cm work well for you by doing the tuning and tweaking dance. In my case for example I can spool my 16cm pretty darn quick when I want to and in the process keep my drive pressure's under better control....until I get up into the higher boost numbers (eg: over 36psi +or-) and that is 'moderated' to some degree by using the larger exhaust housing.

The trick is to generate only enough boost to burn the fuel you're supplying and no more....this keeps drive pressure's down, EGT's better controlled, cylinder pressures down and so on.
You can modify the hot end by gasket matching or 'porting' it and that will help with the moderation (to some degree) of drive pressures. This goes up real quick when you use lots of fuel and an overly small exhaust housing....
The exhaust gases just can't exit the manifold quick enough and start to contribute to even higher EGT's. The delay in passing thru the exhaust housing and into the downpipe allows for that hot exhaust gas to transfer more heat to the ex. manifold and cylinders due to 'back up'.
The thing we're all trying to accomplish is quick spooling, good (but not too high boost value's), smoke control and throttle response.
You really need to match all the components to get it just right.

Ok, that's it....now, since it's late AND I'm getting a tad on the old side I'm gonna use the "you'll have to give PB a break cause he's gitten old) card if I've made any mistakes here....

pb....

PapeCAT

24psi pre getrag
30 psi post getrage

JD730

Saw 35psi peak, did some tweaking, tuning, and advanced the timing a bit and its running around 30psi now.

6Lpowerstroke

pre NV4500 22
Post 26

im loving the sound of the manual tranny

FrdRdnk

On my 21cm h1 I could push it to about 28 pounds, this was only from 3rd up. First and second I would get about 20. This was with my pump maxed out, normally, I'd run somewhere around 20-24 pounds. BTW, got a call the other day. A guy down in Bristol, VA bought the old girl.

gman07

I've got a 12cm housing with the WG held shut. Pulling I can get around 34 psi, but by then the pyro is at 1400*. With the old 18 and a little less fuel, I was only getting around 25.