gunracer1

how bad would it really be? with a 19 cm exhaust housing. i am planning on a #0 plate, to go with the 370s i have now. or should i just go twins. this truck is a d/d that gets used to tow 28k gross a couple times a month. i am really fighting twins, i can build a good set for towing with the 55 on bottom. i would really prefere a single though. mike

Don M

I have the 55, 0 plate, real injectors, etc.

Expect some lag. Its drivebale for certain though.

Moving from a HX35 to 55 is night and day.

Don~

Stamey

Yeah, but what effect will a smaller housing have?

When you talk lag, this is only the time from the moment you hit the fuel until you get boost, right? If I'm drag racing it won't matter since I preload the turbo on the line, right?
When towing, it will just be more lag off the line, right?

Thanks,
Chris

KatDiesel

[quote author=Stamey link=board=7;threadid=18565;start=0#msg174147 date=1061254132]
Yeah, but what effect will a smaller housing have?

When you talk lag, this is only the time from the moment you hit the fuel until you get boost, right? If I'm drag racing it won't matter since I preload the turbo on the line, right?
When towing, it will just be more lag off the line, right?[/quote]

A smaller housing will spool the turbo quicker, but the downside is your EGT's will go up as will your drive pressure if you are not wastegated. And yes lag is when you dump the fuel, the time waiting for the turbo to spool up. Dragracing your correct, you'll launch at a boost level so the turbo is already spooling, but towing more lag yes and you might not be able to control EGT's since you might not be able to keep the RPM's up to keep the turbo spooled and providing enough boost.

Offshoreracer

Kat is right on target. But also keep in mind that in normal driving, say between 35 and 50 mph or so, you will not have any appreciable boost so if you try to accelerate to hard or fast you will have mega smoke and lag. You would probably need to keep your rpms up around 19/2k to help combat the lag and smoke. Fred

Stamey

OK, things are starting to make more sense now.

Thanks,
Chris

danlit

There is also cruizinblackuphillsmokelag. This is found when hills, traffic in the morning speed and exhaust housing size combined with injector size does not match correctly for the guy or gal BEHIND you.
Danny

Stamey

[quote author=danlit link=board=7;threadid=18565;start=0#msg174226 date=1061261447]
There is also cruizinblackuphillsmokelag. This is found when hills, traffic in the morning speed and exhaust housing size combined with injector size does not match correctly for the guy or gal BEHIND you.
Danny
[/quote]

You say that like it's a BAD thing.

Chris

gunracer1

well the truck runs empty most of the time, or loaded real heavy when i have a load. i am going to try it, and see how it does. i figure it should work all right when i get used to driving it. and it should spool decent with a 19cm exhaust, or that is my thinking anyway. what should i set the waste gate at? where does the hx55 go off the map?

Don M

I have the HX55, balanced by Pius @ Bell turbo. It has the 19CM housing and uses the larger size exhaust wheel that is controlled by the engine manufacturer it was designed for.
(Not available from Holset unless you are the OEM ) With the 19CM housing you will get zero boost while cruising the highway @ 70 MPH.
Put your foot in the throttle and the boost will climb slow at first and then........BAMMM!!! 50-55 PSI.

Its a different turbo for certain and requires some adjustment in driving style.

It has been on the truck nearly a year now and I still like the top end pop it gives.

Don~

gunracer1

what are you getting for egts while cruising at 65 to 70 don?

Don M

450 -500 post turbo. Alot of it depends on the injector I have in it too. Sometimes less...sometimes more.


Don~

gunracer1

well i am getting 600 now at cruise so that sounds great to me.