Diff. between Petrol TUrbo and Disel turbo.
04-23-2005, 10:09 PM
#21
3.0 BAR
Join Date: Jan 2003
Posts: 7,082
Re: Diff. between Petrol TUrbo and Disel turbo.
anybody have an egt gauge? my dad has one on his duramax, while driving normally egt sits around 500-600 degrees, if you get on it it gets up there, but cruising it doesn't go over 600. I don't know how gas engines compare though.
04-24-2005, 12:15 AM
#24
1.5 BAR
Join Date: Feb 2005
Posts: 691
Re: Diff. between Petrol TUrbo and Disel turbo.
Originally Posted by Kyle
anybody have an egt gauge? my dad has one on his duramax, while driving normally egt sits around 500-600 degrees, if you get on it it gets up there, but cruising it doesn't go over 600. I don't know how gas engines compare though.
You cant rely on just one EGT to give you accurate results when we are talking about diesel turbos in general.
I know for a fact, that diesel compressions are much higher than with petrol.
Because of their resistance to detonation, I would assume they use leaner AFRs and that would equal higher combustion temps.
But I'm not 100% sure, so feel free to correct me.
04-24-2005, 08:21 AM
#25
1.5 BAR
Join Date: Aug 2003
Posts: 1,194
Re: Diff. between Petrol TUrbo and Disel turbo.
Resistance to detonation? They don't resist what doesn't exist 
In a diesel there IS no detonation, because there is no fuel being compressed.
Also in a diesel, because the burn only happens where the fuel is being injected, you have no lean limit really.
And the more fuel you inject, the higher the exhaust temperature will be, thus too rich means melting your engine, lean is playing it safe.
In a diesel there IS no detonation, because there is no fuel being compressed.
Also in a diesel, because the burn only happens where the fuel is being injected, you have no lean limit really.
And the more fuel you inject, the higher the exhaust temperature will be, thus too rich means melting your engine, lean is playing it safe.
04-27-2005, 12:33 PM
#26
0.0 BAR
Join Date: Feb 2003
Posts: 0
Re: Diff. between Petrol TUrbo and Disel turbo.
Originally Posted by BLAAST
AHAH!!! 
The first turbo I installed on my H22 was a HOLSET 3LD coming from a ford powered industrial snow blower.
This turbo was HUGE, approx equivalent to a T04B. Obviously designed for 24/24hrs heavy duty boosting.
I sharpened the split scroll in the turbine to reduce restriction and slapped it on my prelude without any idea of the specs and flow of the turbo.
It ended up that the turbine, despite it's size, was too small! Boost was coming on like a violent explosion at 2500 RPM and while it was sutaining power all the way to red line, I blew it in a day of track abuse (it was overspinning like crazy)
The downside on truck/indsutrial turbos that are not garrett, is that the specs are not disclosed so it's up to you to do some trial and error. Luckily, it's a lot of fun!
The first turbo I installed on my H22 was a HOLSET 3LD coming from a ford powered industrial snow blower.
This turbo was HUGE, approx equivalent to a T04B. Obviously designed for 24/24hrs heavy duty boosting.
I sharpened the split scroll in the turbine to reduce restriction and slapped it on my prelude without any idea of the specs and flow of the turbo.
It ended up that the turbine, despite it's size, was too small! Boost was coming on like a violent explosion at 2500 RPM and while it was sutaining power all the way to red line, I blew it in a day of track abuse (it was overspinning like crazy)
The downside on truck/indsutrial turbos that are not garrett, is that the specs are not disclosed so it's up to you to do some trial and error. Luckily, it's a lot of fun!
Holsets like high pressures - most don't become any more efficient than a dinosaur T04B until they hit above 12-15 psi. I'd say your blown turbo - wasn't. Diesels don't run a lot of oil pressure, and the ~0.080" 'restrictor' found in the OEM feed line is typically way to big for a high oil pressure gas engine. You probably just flooded the bearings, the turbo started passing a ton of oil, and the turbo might be a happy little camper again with a little dissassembly and cleanup. Look for minor coking where oil was passing the turbine wheel/ring seal - if you're lucky you won't even have to replace the ring seal and can just clean off the coking and toss it back together.
I've got a pretty good grasp of common US Holsets made through the 90's - more or less. When I have a question, or am looking to buy one with a warranty for cheap (lots cheaper than Garrett equivalents, the HX series are GT series equivalents), I call Jaymez at Diesel Injection Service in Cincinnatti, OH. He's a super cool guy, racer friendly, and has busted his hump for me over speshul riceboy requests in the past.
Thread
Thread Starter
Forum
Replies
Last Post
