Turbo tb 45 compression

[mudbug]

Hay guys could some one lead me in the right direction , I have a TB 45 with a garret turbo stuck to the side of it placed in a GQ wagon , the patrol goes great but the compression from the standard motor is to high and pings every now and then I am running 9 pound max (with a modified fuel rail and injectors, it also has 42 rods for added strength) but want more . I have to remove the head due to oil leaking from the front of the head and block , what might be the best way to reduce the compression : thicker head gasket , do some head work , or maybe looking at different pistons and where could I start looking , I am from Adelaide

cheers
ready to pop !!

[nissannewby]

Is it intercooled? What size turbo?

[mudbug]

yes its intercooled and a garret 3582 ballbearing

[nissannewby]

Yeah I would be looking at custom pistons to suit.

[BigRAWesty]

Is decompressing the way to go? To me that's just offsetting the turbo so why not just turn down turbo?
Could it be more timing or Fuel mixture?

[nissannewby]

Is decompressing the way to go? To me that's just offsetting the turbo so why not just turn down turbo?
Could it be more timing or Fuel mixture?

On a petrol it is, it's already on the low side for that setup boost wise. He could get the tune looked at and make sure its nothing simple like timing. If it hasn't had the compression lowered then what they do is basically start to diesel (compression ignition) so it's already starting to ignite before its even sparked.

[Ben-e-boy]

big rig had the head done. I think its about 7.8:1 but he still had to take some timing out as it was still pinging. the mechanic would have prefered about 7.5:1 so some decent timing could be put in to it

[Alitis007]

You could fit a Cometic layered steel head gasket so it will act like a decompression plate, i had a 1.9mm thick one on my vl to lower the compression enough so it wouldn't ping but i don't know how that will affect the push rod length. To do it properly you should fit some low comp pistons but that would be a 2k exercise but you will have piece of mind knowing its done correctly.

[davo94]

Talk to any smart engine builder and get you compression chamber cc'd mod the head to lower the comp slightly and ensure the flame front is correct. Get a mls head gasket slightly thicker than standard. Have you looked at a tune if so ditch the maf and map tune it.
Are you running standard fuel pressure? Whats your air fuel ratio (with wide band installed)

[05_ENFORCER]

As davo94 said, if you have the head off, talk to a head guy.
If you were in W.A I can point you in the right direction.
You may as well grab some head bolts and a Cometic head gasket also


.

[mudbug]

I am running an aftermarket ecu EMS I think I have 14 degrees in the timing and running standard fuel pressure I supplied a fuel regulator to increase pressure but they never used it not sure what air fuel mixtures it is but as it is that's the maximum timing and boost I can run with standard compression

[davo94]

I would look into another tuner. Standard n/A injectors and pressure is where you problem lies. The comp ratio you have is ok any lower and you will drop low down torque and pick it up higher witch we all know isnt what you want for good bush work.

[mudbug]

I did have standard injectors they weren't good enough I could only get about 5 pound boost before running out of fuel , I had the fuel rail modified to suit bigger injectors which worked managed to get up to 9 pound, timing was left at 14 degrees due to pinging and I asked if they needed the fuel regulator to increase fuel pressure the answer was no I didn't chase up on why but it might be due to low boost due to compression and don't need it yet, not sure , might now chase that one up with another tuner

[davo94]

I did have standard injectors they weren't good enough I could only get about 5 pound boost before running out of fuel , I had the fuel rail modified to suit bigger injectors which worked managed to get up to 9 pound, timing was left at 14 degrees due to pinging and I asked if they needed the fuel regulator to increase fuel pressure the answer was no I didn't chase up on why but it might be due to low boost due to compression and don't need it yet, not sure , might now chase that one up with another tuner

How many lbs are the injectors? Do you know if they are maxed out ? If you lift the fuel presure and inject more fuel I cant see why your stuck at 9psi..

[mudbug]

Not sure on lbs but as a number they are 550 or 600 they are good for 200 plus rwkw at the moment I have 161 rwkw on 33 with 3.9 diff ratio running an auto box Im not the tuner and all I have been told is that with the compression 9psi and 14 degrees on the timing is all I can get without destroying it but I will chase up the fuel pressure with the tuner and see what comment I get back, you have me thinking now, they did how ever tell me that they don't do high kw tunes on standard motors they stick with a safe tune for reliability don't think they want a bad name of blowing up engines which I guess is fine

[scottmeister]

Mate it shouldn't be pinging at 9psi. Do not reduce the compression unless you want a dog of an engine to drive. Is it pinging under full boost - and if so, at what RPM? Do you have a wideband - how is the fuelling at this boost? The 4.5s like a funny ignition timing curve, they like full advance by 2500 rpm, then you need to pull timing from then through to about 3500 rpm before adding it in again. I have run 17 psi though the TB45 on 98 with no worries, around 12-14 degrees @ 4000 rpm, AFRs around 11.5. Nowadays I just run 15 psi on E85, needs a bit more timing and makes great power :-)

[jff45]

@mudbug, as I'm currently in the process of doing a similar turbo install on my TB45E auto, I'd be interested to know if you've done any mods to your auto trans and how long how have you driving it with that sort of power?

[mudbug]

Mate it shouldn't be pinging at 9psi. Do not reduce the compression unless you want a dog of an engine to drive. Is it pinging under full boost - and if so, at what RPM? Do you have a wideband - how is the fuelling at this boost? The 4.5s like a funny ignition timing curve, they like full advance by 2500 rpm, then you need to pull timing from then through to about 3500 rpm before adding it in again. I have run 17 psi though the TB45 on 98 with no worries, around 12-14 degrees @ 4000 rpm, AFRs around 11.5. Nowadays I just run 15 psi on E85, needs a bit more timing and makes great power :-)

Hey scottmeister you sound like you no what you are talking about I don't fully understand the tuning side of things when it comes to ( wideband fuelling at boost and so on ) but would like to. Getting 17 psi would make my 4bee unreal compared to what it is now. Your beast must be a monster is it still a standard motor , Can I bring your information to the people who tuned my car and see if they can improve on what I have , Thanks for that info I much appreciate it cheers . PS running on E85 .....Wow would not have thought of that how is the economy compared to 98 , not saying a tb45 turbo would get great economy ! I didn't turbo mine for that but in saying that I have improved my economy especially on the open road compared to the standard tb42 I had in it prior ( fully loaded I get approx. 17L per hundred ) but as I said I didn't do it for economy , fun factor was my intentions and still is so more psi is what I want .

[mudbug]

@mudbug, as I'm currently in the process of doing a similar turbo install on my TB45E auto, I'd be interested to know if you've done any mods to your auto trans and how long how have you driving it with that sort of power?

Hi jff45 at first my trans was standard but after the first tune it was a little worse for ware but I have had some great fun with it prior for years so I had a shift kit put in ( not full manual ) but one step before , so you can still drive it normal or you can manual shift it . It shifts harder now and under normal drive its quite smooth , I also had the converter re done and a valve body from a GU ( mine is a GQ ) put in .I had one problem with it, due to the power / torque increase the factory trans computer could not function properly, the shift would change real quickly ,EG just as you take off ( under normal driving condition ) it changes to second then third shortly after that , its not a problem because the torque you gain from the turbo makes up for it ( approx. 700nm is what I have ,so I have been told) and the lock up converter would not stay in, it would unlock it self under slight acceleration and would not go back in unless I turned the car off , but still the lock up would not lock . you have to do one of two things put a manual lock up switch on it ( with the GU valve body you can lock the converter in all gears , an advantage when going off road ) or fit a aftermarket computer to the trans these can all be sourced from wholesale automatics , I chose the switch mainly due to cost , the switch is simple to install and does the job ,the computer how ever does quite a lot of things such as short shifting holds gears longer shift harder or softer auto lock up or manual lock up it does quite a lot of things and you can program it to suit and you can change it at leisure .If you want to spend close to $2gs then the computer is the way to go if not under $300 for the switch delivered to your door with instructions . As for how long I have been driving it I did the conversion in August 2013 other than the pinging under heavy acceleration and the oil leak from the head ,( that was not from the conversion ) its been unstoppable and is still going strong with no signs of fatigue

[jff45]

Did you have a shift kit put into your own valve body or did you do a valve body swap?
I fitted a TransGo shift kit to mine some time back but it's not a real performance kit.

The Wholesale TC lockup kit is way overpriced for what it is. I did my own with a Jaycar frequency switch that arms the circuit at 60 kph and I can switch it on with the rear demister switch. Her's a copy of the circuit diagram..

http://i257.photobucket.com/albums/hh207/JFF45/FSschema.jpg

My concern is that the increased torque will put too much of a load on the TC clutch... and the other standard components as well.
I do have a spare trans that I could redo with better components if mine starts to show signs of not handling it.