can anyone clarify whether a diesel turbo could be properly tuned for use on a petrol engine? as far as I can tell I thought a turbo was a turbo... they all produce CFM just some sooner than others. I am guessing by putting a diesel turbo on a petrol engine you may get alot less lag?
any help would be great, the only spare turbos I can find in english breakers yards all seem to be fookin' diesels!

 

turbo is a turbo as far as I know. You just need to find one the right size.

Most turbo diesel engines run lots of boost, and the turbos spool really quickly.

 

I can't remember, but some or all diesel turbos don't have a seal on the compressor side so you'll be leaking oil

 

so which is better

 

i guess most of you do not know about the Holset HX35w, huh??? LEARN, fast.

 

There are alot of succesful gasoline engines using diesel turbos. As for the turbo spooling faster just becasue it is a diesel turbo...is BS. It is all in the usual turbo wheel and housing specs.

There are seals on both turbine and compressor sides of diesel turbos. What you have to watch out for is the type of seal. Diesel turbos have a "less-agressive" passive seal which is more prone to leaking under high CCP and poor drain back capacity.
Gas turbos have "more-agressive" active seals that seal a bit better under harsh conditions.

Which is better? A gas turbo would be the best bet. But considering that you can find some bargains on diesel turbos, you won't know unless you try it out first or know someone who is using it.

Holset HX35w, is a good example of a diesel turbo that has good success. I've talked to a decent amount of BWarner and Garrett engineers about this and they reference the above material as something to keep in mind.


Modified by SLPR at 11:27 AM 8/20/2003

 

the HY35w is good too


but no bigger

 

good answer SLPR but dont forget that most (industrial)diesel engines are very large and redline very low (say like 5000 rpm) so boost has to build quickly and at low rpm or it would be useless

 

http://cgi.ebay.com/ebaymotors...33742

bam....t3/60-1 bascially....and it's CHEAP...but don't bid on this one...it's Speed Phreaks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rb08 &raquo;</TD></TR><TR><TD CLASS="quote">good answer SLPR but dont forget that most (industrial)diesel engines are very large and redline very low (say like 5000 rpm) so boost has to build quickly and at low rpm or it would be useless</TD></TR></TABLE>

True, but these diesel engines also have MUCH more exhaust manifold energy at those low speeds than gas engines could ever hope for. Diesel will alway contain more BTU energy than common gasoline fuels.
If you look at most on road diesel engines the exhaust housings are huge. Just something to keep in mind.
I have an on-road diesel VGT turbo running on a test set-up now, but I really need a different spec turbo to get the best performance. This is why I bring up that diesel turbos are not "always" the best choice.

 

im not trying to disagree with you i am just adding other reasons y the housings are soo big. another thing is that diesels have high compression because they work off of like a "glow plug" design they have no real formal igniton they just get the fuel charge so hot that it ignites itself. nothing can beat a properly matched engine/turbo

 

modern Diesel Turbos have adjustable exhaust blades, those will get damaged when you are using it on hotter burning engines, so it is not a good idea to run them on patrol engine. The adjustable blades are the reason why you get an quick spool up.

VW TDI VTG-Turbo with variable geometry

 

has anyone managed to produce a succesful turbo setup on a petrol engine using a diesel turbo?

 

People use the turbos from TDI VWs on the gas 1.8 and 2.0 engines all the time. Mostly because it just bolts up. The turbo is way too small but it does work and lots of people have used this setup with quickspooling success

 

edited for... A six cylinder pulsed style manifold, assists in available turbine energy by about 10-20% but is a little limited in high rev applications over ~6500 rpms.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SLPR &raquo;</TD></TR><TR><TD CLASS="quote">

True, but these diesel engines also have MUCH more exhaust manifold energy at those low speeds than gas engines could ever hope for. .</TD></TR></TABLE>

? Try much less. Diesels have far less exhaust energy due to greater carnot cycle efficiency.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SLPR &raquo;</TD></TR><TR><TD CLASS="quote"> Diesel will alway contain more BTU energy than common gasoline fuel.</TD></TR></TABLE>

Correct. However, this has nothing to due with available exhaust energy.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SLPR &raquo;</TD></TR><TR><TD CLASS="quote"> If you look at most on road diesel engines the exhaust housings are huge.</TD></TR></TABLE>

This is usually due to the fact that the displacement is generally larger than the *gas* turbos we are used to looking at.




Modified by Signal Auto at 1:41 PM 8/21/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HXMan &raquo;</TD></TR><TR><TD CLASS="quote">turbo is a turbo as far as I know. You just need to find one the right size.

Most turbo diesel engines run lots of boost, and the turbos spool really quickly.

</TD></TR></TABLE>

Diesel turbos do not spool really quickly. A big rig is set up for long distance, trans-continental hauling where if he's spooled the whole time the turbine housing is acting as a restriction which kills fuel efficiency. Aside from that, you've got it

http://www.toohighpsi.com has used $200 used Holset HX40 on Ford V8s to create solid 9 second cars. Just like any turbo, you should plot the compressor map to your engine.

 

For the originator of the thread; usually you can use a diesel turbo on a gas engine. A major difference will lie in the intended rev range of the engine however, and also whether you want torque (low lag situation + smallish turbine housing) or top end bhp (more lag, larger turbine housing). Another detail to remember is usually you can simply change the turbine housing to a bigger A/R which will better suit the gasser engine.

Oh, and VNT turbos have issues with the moving parts (ie vanes, vane actuator etc) in gasser engines.