Outer Limits 4x4 Board

Forgive me if I go over any old ground as I havent read all pages. Except for the last 12 months I was running the chassis dyno for Swift Automotive/Gasresearch in Dandenong, prior to that I worked for Gasresearch Aust.
I did a LOT of turbo LPG, my previous ride was a shorty 4.2 straight LPG, intercooled and valve springs, it made 180 rwkw on 14psi and 230 rwkw on 18 psi.
I have and still do tune LPG for Ontrack, Andrew is a top operator who does great work.
Chinese coolers do work, there are better ones but on a buget sure beat having none, you can run more timing or boost due to the lower intake air temps, I've seen intake air temps 10 degrees above ambient with outlet temp as high as 100 degrees, this could mean as much as 5 or 6 degrees more timing and that can mean 20 30 kw at the wheels.
Turbo sizing is much debated, personally I think some people go too small in turbo to eliminte lag, this is just an opinion, I've found that with very small exhaust housing the turbo dose certaily spool fast but exhaust temps are significantly higher and considerably more boost is required to make the same HP. You need to run a roller like a GT28RS which will work but will not last as long or make the power of a GT3582RS which has a larger exhaust housing and A/R ratio as the exhaust is being restricted by the small housing. Autos work best as the turbo dosen't loose speed on gear shifts.
Without a cooler you have to run less timing, less timing means late ignition and the combustion charge comes out the exhaust valve much hotter, high exhaust and engine temps result, the more timing you can run without detonation the cooler the exhaust temps as the combustion has more time in the cylinder to complete, also you make more power as your not wasting heat energy out the exhaust.

The more you decomp your engine the poorer it will perform off boost, if you want to run 20 psi a lot decomp to 8.5psi if you want maximum driveability and low torque keep the compression std, all I did to mine was valve springs as the valves blew open and I modified a dissy to accept a Hall effect and used a delco 808(VN_ computer to control a 3d ignition map with 2 bar MAP sensor.
My engine ran 16 degrees total at 14 psi.

Joel

PGS 4WD wrote: You need to run a roller like a GT28RS which will work but will not last as long or make the power of a GT3582RS which has a larger exhaust housing and A/R ratio as the exhaust is being restricted by the small housing. Autos work best as the turbo dosen't loose speed on gear shifts.

Joel

Well said. I agree with pretty much all of that, especially the part about getting away with bigger turbo's with Auto transmission's.

A big turbo on a small engine with a manual gearbox and it's fairly rapid how fast the boost falls after the throttle is closed.

Grant.

Huh, I may have confused myself, isn't that sort of what I said, I was assuming all the discussion was on a 4.2, the beauty of a auto is that you dont have to throttle off on gear shift and you can stall it up to take off, if your brave enough you can even two foot it keeping boost on round corners if you're game. Like you said, shutting the throttle on the turbo will kill the boost fast, hence the manual is disadvantaged as you close throttle to gear shift. Big blow off valves help and set the spring loose, I like the Bosch ones that are actually always open when the engine is in vacuum as it allows the turbo to freespool faster than what the engine is consuming air. You get boost more rapidly when transitioning from cruise, they are not big though so I usually put one before and one after the intercooler, this when dumping to atmosphere also keeps the intake air temps down as it reduces cooler heat soak.

are the bosch ones off a particular vehicle or do they sell them as a acessory?

They were factory fitted on Porche, Volvo and Saab to my knowledge, you can get them through petroject though cheaper.
Joel

WOW This thread has turned into the most interesting read now you certainly know your stuff PGS 4wd.

I would love to bring my car to VIC for a dyno tune but it think it's to much of a drive from here in QLD. Do you have any contacts up here that know there stuff as well as u do?

Also that Bosch bov's sound a awersome investment.


Thanks alot for the great info mate !


Thanks

Rick.

Ive been burnt recomending people, I would suggest ring Gasresearch who are now in QLD they may have someone they recomend.

Joel

This is the only qld place they recommend,

Tony Motson's Performance Centre Brisbane 07 3277 7766 Ben

It looks like your car is tuned in good anyway looking at your dyno sheet. Wait till you intercool it then pump up the boost.


I sent you a pm pgm cheers

PGS 4WD wrote:They were factory fitted on Porche, Volvo and Saab to my knowledge, you can get them through petroject though cheaper.
Joel

They are also fitted to Ford Xr6 Turbo's and Fpv typhoons/tornado's so they are very cheap from ford...

You'd think I'd remember that given my other car is a BF 6 spd XR6T, built after may 06 with the Typhoon rods and valve springs. I tune SCT also, it makes 245 KW at rear, tune only on 9psi, they are a kick ass donk with a huffer.
Joel

terrytuffnut wrote:This is the only qld place they recommend,

Tony Motson's Performance Centre Brisbane 07 3277 7766 Ben

It looks like your car is tuned in good anyway looking at your dyno sheet. Wait till you intercool it then pump up the boost.


I sent you a pm pgm cheers

Yeah that's who they told me to go see...

I wounder if anyone has been there or not.


Before i even attemp fitting a cooler i want to find a tunner that will be able to tell me how much i'm looking at paying for the tune and what i should look at upgrading or whatever before i go there so i don't waste my money finding out that i needed something ...

To up the boost i was going to get a turbo smart bleed valve thing would this be the best way?

I have to go to work

Cheers

Rick.

Adjust your wastegate to what psi you want

Dont go crazy adding boost, you may find that your fuel supply may be insufficent for more boost/power and also if the timing has been set to run your current boost level adding boost will cause detonation and potential engine damage.
Fit the cooler as lower intake air temps reduce the likely hood of detonation.
If you lean the engine out or it detonates you can kill it very quickly, particularly with LPG.
When the cooler is fitted the LPG balance line needs to go between the turbo and the cooler.
Joel

well now it has been running for a bit now and i have done a few extra things ..

Fitted a sus lift 3" and fitted 33's tyres.

Also put silcon oil in my clucth fan and now it keeps my car heaps cooler.



Bit of a problem now though


Before i did anything to my car i could hit a certain hill at 100 and could climb to 130 quite easy.


Now i hit the hill at 110 and get to the top doing 105 or so


WDF is going on my car feels like it goes like shit now feel like it has a massive flat or something i'll try explain..


Say i'm doing 100 and i push the pedal down 2cm it starts to take off ok but when i put my foot to the floor my car seems (no joke) to go slower Like it has no ballz or nothing at all just touchy for that first 2cm or so but nothing after it really dissapointing really for the amount of $$$ i spent

I'm thinking maybe my timming as when i do push it down the 2cm i'm not 100% sure but i think it not making huge boost so my Boost Timming Master isn't retartding it.. ( that's all i can think of).

How much of a diff will a ZD30 air cleaner box make as i'm trying to get hold of one to replace that bloody noisey annoying pod filter.


Thanks for any help

Rick.

dont have any experience with LPG and Turbos but Ive been following this thread for awhile now.

Keep in mind that with the 33`s your speedo will be out by approx. 10%, depending on how accurate it was.

At a guess it sounds like you cant supply enough fuel/LPG????

On carbys you get an initial squirt of fuel via a plunger or power valve which gives you the initial punch, I dont know what happens with LPG though.

Also, the 33's are a heavier tyre, which will affect the performance. Also the change in diamiter will lead to the speedo being out.

Layto....

azzad wrote:dont have any experience with LPG and Turbos but Ive been following this thread for awhile now.

Keep in mind that with the 33`s your speedo will be out by approx. 10%, depending on how accurate it was.

At a guess it sounds like you cant supply enough fuel/LPG????

On carbys you get an initial squirt of fuel via a plunger or power valve which gives you the initial punch, I dont know what happens with LPG though.

Yeah thanks mate it's werid i don't know ey ... it has me worried as i don't want to blow up the car and turbo

I just farking wish there were someone in south QLD or north sydney way i don't mind driving if i know someone can get my car going the way i want!!!!!!!!!!!!!!!

It feels like it has just jumped out tune and now has lost any power/tourqe it used to have...

Unless 33's and a lift make it go like barely any faster then a stock tb42..

Thanks

Rick.

lay80n wrote:Also, the 33's are a heavier tyre, which will affect the performance. Also the change in diamiter will lead to the speedo being out.

Layto....

How much out are we talking like 1 or 2kms ? the tyres are barely any smaller then my friends MTR 35's the Micky Thompson tyres are big compared to others..

Thanks for ya help

Mulisha it sounds like something has changed and it is leaning out. Check all your hoses.

If it's lean the more throttle you apply the worse it gets.

Does sound lean.
Would be good to go for a drive with a sniffer in it.

Thanks alot guys

What hoses am i looking at raptorthumper?

Thanks alot

Rick.

33's and a 3" lift will knock a far amount of power out of it. there is a lot more wind drag. plus there is a lot more rubber its trying to spin, and if you went a mud tyre you loose more, chapmans ran a before and after with a set of baja claws and they lost 30-40 rwhp.

How much out are we talking like 1 or 2kms ? the tyres are barely any smaller then my friends MTR 35's the Micky Thompson tyres are big compared to others..

its not a matter of how many kms. its a percentage. approx 10% for 33's on a patrol.

60kmh = 66kmh
100 = 110

its no comparison, but i ran NO muffler on my tb42....then when i put the 6in lift and 35's on it, i put a straight through performance muffler on it, and GAINED power.

hopefully you will get there in the end.

PAUL

Mulisha wrote:

lay80n wrote:Also, the 33's are a heavier tyre, which will affect the performance. Also the change in diamiter will lead to the speedo being out.

Layto....

How much out are we talking like 1 or 2kms ? the tyres are barely any smaller then my friends MTR 35's the Micky Thompson tyres are big compared to others..

Thanks for ya help

As the guys have said, the amount the km's on your speedo are out will the the same percentage as the increase in the tyre diamiter over standard. So say if you had 30's on standard, a 33 inch diamiter tyre is 110% of that, so at 100Km/h indicated, you are doing 110, at 60 you are doing 66 etc. Make sure you factor this in to your testing. Also, the extra height will give you a less aerodynamic efficiency, which shows up at higher speed. It takes something like 8 times the power to get to 200km/h, as it does to get to 100km/h (i said something, if im out dont flame me ). The increase in tyre weight will also effect not only the feeling of power, but also the response to throttle, as they have a greater inertia to overcome. Also the open void style of tyre increases the amount of torque required to turn them. Try running your standard tyres and see if it makes a difference. Even check your tyre pressure .
Also check over your motor, make sure a vacum hose etc has not come loose.
Layto....

i agree, sound like its leaning out, on road high speed o2, Check for boost leak to converter on balance line. I've seen some plastic converter lids leak under boost (B2 Converters) will cause lean out and gas smell. The location of the balance line may be incorrect, sometimes you need to put the tube through the intake pipe with a chafer towards the air stream to increase the converters reference.

Joel

Thanks all so much for ya help there are a few things that seem like they would loose me a bit of power...

PGS 4wd:

I have a werid BOV that has ports right around the outside of it and it used to make a gas smell when it opens but yesterday when i was on the highway doing my 110 on my boost gauge was saying 0 boost maybe a little under and i could smell gas and the BOV should be closed becuase my foot was still on the pedal..


Might have a good look under the bonnet now and take some pics and stuff..

Cheers everyone for ya help ..

If this converter cover has cracked i hope there is some type of warranty becuase it's like 2 months old

o well i'll have a look now..


Rick.

It takes something like 8 times the power to get to 200km/h, as it does to get to 100km/h (i said something, if im out dont flame me

).

it makes sense i think. in 5th gear i do 1100rpm at 50kmh.....2200rpm at 100kmh. now my tb42 revs out to 5300rpm...i got a thinking the other day, in theory i should be able to do 200kmh at 4400rpm.

so i guess wat ur saying lay8on is the fuel/power/right boot needed to get to 200kmh would be a hell of a lot more then all the forces acting agasint the car (wind, friction etc)

Make sure the BOV isnt after the mixer!
It may be sneaking open, they can do this when there is a restrictive mixer/throttle as the boost pressure on the BOV exceeds the boost in the manifold where the BOV gets it equalizing pressure from(this hose goes to vacuum when you close the throttle) If you have 10 psi at the intake pipe and 7 in the manifold the BOV can open if its internal sping pressure is less than 3 psi.
Joel

Well i had a look and i couldn't see anything out of whack by the looks of it went over everything a little started the car and tryed to smell for gas couldn't smell anything. Couldn't see any cracks or anything and the converter has a metal lid.

Umm a few things that i kind of took notice of ..

My alarm makes a beep noise when i turn the lights on like there a low battery maybe not sure will see about that tommorow and see if that is anything to do with anything lol...


One other thing when i flick my key on to just turn the sterao on and not to start the car sometimes the car will lick kick over never used to


Anyway i'm off

Thanks everyone for ya help hope i can get to the bottom of this turbo thing in the end becuase i'm kinda regreating doing it almost becuase it's a biatch to find good service and nice people to talk to and willing to hear me out and not just try make a quick $$$...

It's like i need to drive to vic to get someone that knows how to dyno a car i swear lol...

Is there anyone up here that someone knows of that does a good job and knows there shit and trys to get decent reliable power out of ya car...


Cheers

Rick.