1.6 T/D boost pressure

[Rabbit TD]

What kind of boost pressure should be expected from a just rebuilt 1.6 T/D with the stock t3 turbo and factory settings on the pump and rebuilt 155 bar injectors and what is normal boost at just cruising at 65 mph with this setup.  I need to establish a base line for this engine as I don't think this turbo is a good one that's on it now.

[jtanguay]

What kind of boost pressure should be expected from a just rebuilt 1.6 T/D with the stock t3 turbo and factory settings on the pump and rebuilt 155 bar injectors and what is normal boost at just cruising at 65 mph with this setup.  I need to establish a base line for this engine as I don't think this turbo is a good one that's on it now.

it all depends on how much pedal you're giving it, and what rpm's the car is at.  with the wastegate disabled i was at about 15 psi @ 65 mph @ 3000 rpm or so with light acceleration.  i tuned it back a little and hooked the wastegate back up and saw about 5-6 psi.

just cruising it should be about 5 psi or so.  more than that to me is counter productive, unless you have a nice intercooler setup.

[Rabbit TD]

What kind of boost pressure should be expected from a just rebuilt 1.6 T/D with the stock t3 turbo and factory settings on the pump and rebuilt 155 bar injectors and what is normal boost at just cruising at 65 mph with this setup.  I need to establish a base line for this engine as I don't think this turbo is a good one that's on it now.

it all depends on how much pedal you're giving it, and what rpm's the car is at.  with the wastegate disabled i was at about 15 psi @ 65 mph @ 3000 rpm or so with light acceleration.  i tuned it back a little and hooked the wastegate back up and saw about 5-6 psi.

just cruising it should be about 5 psi or so.  more than that to me is counter productive, unless you have a nice intercooler setup.

Thanks for the answer.  I am getting 5-6 just cruising on flat ground at 65 with the wastegate actuator still hooked up.  I thought they didn't start bleeding off till around 11-12 and I haven't messed with the actuator hoses yet.  I was thinking even if the actuator is worn {bad diaphram} it just would take a higher pressure before it would actualy start to bleed, am I thinking wrong on this as I am new to the turbo world here .

[jtanguay]

What kind of boost pressure should be expected from a just rebuilt 1.6 T/D with the stock t3 turbo and factory settings on the pump and rebuilt 155 bar injectors and what is normal boost at just cruising at 65 mph with this setup.  I need to establish a base line for this engine as I don't think this turbo is a good one that's on it now.

it all depends on how much pedal you're giving it, and what rpm's the car is at.  with the wastegate disabled i was at about 15 psi @ 65 mph @ 3000 rpm or so with light acceleration.  i tuned it back a little and hooked the wastegate back up and saw about 5-6 psi.

just cruising it should be about 5 psi or so.  more than that to me is counter productive, unless you have a nice intercooler setup.

Thanks for the answer.  I am getting 5-6 just cruising on flat ground at 65 with the wastegate actuator still hooked up.  I thought they didn't start bleeding off till around 11-12 and I haven't messed with the actuator hoses yet.  I was thinking even if the actuator is worn {bad diaphram} it just would take a higher pressure before it would actualy start to bleed, am I thinking wrong on this as I am new to the turbo world here .

nope your right.  the wastegate opens only as the 10 psi is achieved.  so regardless of wastegate being enabled or disabled, you should see whatever below 10.

[Rabbit TD]

Yeah that's what I thought, I have a feeling I just have a pretty useless turbo as the most I ever saw was 7 one time with the T/D pump on it and the temps went up to 1350 going through the gears pretty hard.  I never did try that pump on my mountain pull.  I think I'm going to be in the market for anoher turbo soon but damn it did run pretty good though and didn't smoke to amount to anything.  I still have the original t3, I never tried it because the actuator was all rusted away but I didn't know about the boostvalve tricks then, it probably does need seals though but I might give it a try just to see if it makes any difference.  I have to get the turbo balanced if I put the other compressor section from the old one on this stage 1  as they call it contraption.

[Rabbit TD]

5-6 for flat 65 cruising is right.  If max boost is around 10-11 then all is normal.

That's the problem, I never see anywhere near 10-11. I did see 7 one time and the temps were getting close to 1400 just going through the gears with factory settings on the pump timed to 1.0 and those injectors were pretty good but I have rebuilt Giles ones now to make sure they themselves are at least right {155}

[Smokey Eddy]

i didn't read all posts except for OP. but i have a fresh 1.6 with a 1.9 head on it.

Mine, with no waste gate or BOV, will do 25psi pretty quick. probably more if i had a road i could drive that fast on.... not much over 30 though. not without some heavy fueling and stupid big exhaust.

highway 90-110 km/h runs about 6-8 psi. at 140-150 km/h it hits 10-15 range.

I have the idle screw backed all the way out and the fuel screw turned IN until it started to change the idle higher than i wanted.

it boosts VERY hard in 3rd going from 70-100 at half throttle and ,my car anyways, makes terrible drive line noise at WOT - bust CV's.

I'm very happy with the T3. Merging onto the highway i make no black smoke visible in my mirrors or a quick shoulder check anymore.

a BOV set to 8 psi (or what ever it is) is such a pointless value for a T3... driving it i feel like the T3 should be regulated to 20 psi. 10-20 is when it really shines.

[Rabbit TD]

Probably a leaky wastegate.

Yes I thought about that too but I think the guy actualy did a good job when he rebuilt this thing, it was totaly diasembled and glassbeaded before the rebuild and I did remove the cover at the wastegate end to look at the valve and it's all clean in there too.  I wanted to just go ahead and hand lapp the valve but the actuator on this is one of those tin can pressed together types that only Houdini could get apart without ruining it but I do think the valve is sealing.  I read here a lot about the t3-t4 hybrid turbos and I looked at gpopshop's website and they talk about different stages as well as MJMturbos were I bought this one.  I didn't know a damn thing about turbos when I ordered this thing but he said he would upgrade it to the next size compressor  wheel amd machine the case for it to fit.  I don't know what the next size wheel is, could that be the t4 wheel and I just have a turbo that is too big for this stock motor to spool right?  I feel so damn dumb that I can't give any specs on this thing other than the wheel is definately bigger just looking at it.  Would a stock 1.6 T/D with factory fuel and timing settings spool a hybrid like the t3-t4 if that is what I actualy have and I want to keep this an economical motor as well and don't want to turn the fuel waay up :lol: .  If I could get 80 horses out of it I'd be happy, I'm not trying to set the world on fire because it's doing that all by itself

[AudiVWguy]

What kind of EGT are you seeing at 65mph? What size is the down pipe?
Doesn't boost equate to heat? So crusing at maxium efficency would be almost no psi?

I'm still trying to understand where the sweet spot would be for crusing speed vs. boost pressure vs. EGT = best efficency

In my case, at 70 mph I'm at about 1.5 psi boost, EGT's ranges from 590 to 650 F. If I get a little head wind or a slight incline the EGT's go to 800-850 and the boost is at 3 psi.
This is with a Srarion IC. Oil temps are at the 175 F range. 2.5 in dp.
If I understand correctly, you're trying to balance the least fuel to get the most boolt. So maybe my turbo(Roto-Master) is a little on the big side?

[jtanguay]

Probably a leaky wastegate.

Yes I thought about that too but I think the guy actualy did a good job when he rebuilt this thing, it was totaly diasembled and glassbeaded before the rebuild and I did remove the cover at the wastegate end to look at the valve and it's all clean in there too.  I wanted to just go ahead and hand lapp the valve but the actuator on this is one of those tin can pressed together types that only Houdini could get apart without ruining it but I do think the valve is sealing.  I read here a lot about the t3-t4 hybrid turbos and I looked at gpopshop's website and they talk about different stages as well as MJMturbos were I bought this one.  I didn't know a damn thing about turbos when I ordered this thing but he said he would upgrade it to the next size compressor  wheel amd machine the case for it to fit.  I don't know what the next size wheel is, could that be the t4 wheel and I just have a turbo that is too big for this stock motor to spool right?  I feel so damn dumb that I can't give any specs on this thing other than the wheel is definately bigger just looking at it.  Would a stock 1.6 T/D with factory fuel and timing settings spool a hybrid like the t3-t4 if that is what I actualy have and I want to keep this an economical motor as well and don't want to turn the fuel waay up :lol: .  If I could get 80 horses out of it I'd be happy, I'm not trying to set the world on fire because it's doing that all by itself

if the wastegate wasn't lapped, i would highly suspect it to be leaking some if you can't develop more than 7 psi boost.  even with a larger turbo, they will spool but later in the rpm range depending on size.  its either that or you have a boost leak.  

don't forget to check that cloth line's connections.  over time they get hard and crack and leak boost.  mine actually fell off once and i lost a lot of power and the boost gauge showed 0 psi.  i cut off the end of the hose and re-attached it, and bingo problem solved.  

since the turbine is still spinning, EGTs go up and since there isn't enough boost pressure compensating, they will rise even higher than normal.  essentially its like having an exhaust restriction, due to the lowered efficiency.  the turbo pressures should be at a 1>:1 ratio for maximum efficiency.

[Rabbit TD]

Probably a leaky wastegate.

Yes I thought about that too but I think the guy actualy did a good job when he rebuilt this thing, it was totaly diasembled and glassbeaded before the rebuild and I did remove the cover at the wastegate end to look at the valve and it's all clean in there too.  I wanted to just go ahead and hand lapp the valve but the actuator on this is one of those tin can pressed together types that only Houdini could get apart without ruining it but I do think the valve is sealing.  I read here a lot about the t3-t4 hybrid turbos and I looked at gpopshop's website and they talk about different stages as well as MJMturbos were I bought this one.  I didn't know a damn thing about turbos when I ordered this thing but he said he would upgrade it to the next size compressor  wheel amd machine the case for it to fit.  I don't know what the next size wheel is, could that be the t4 wheel and I just have a turbo that is too big for this stock motor to spool right?  I feel so damn dumb that I can't give any specs on this thing other than the wheel is definately bigger just looking at it.  Would a stock 1.6 T/D with factory fuel and timing settings spool a hybrid like the t3-t4 if that is what I actualy have and I want to keep this an economical motor as well and don't want to turn the fuel waay up :lol: .  If I could get 80 horses out of it I'd be happy, I'm not trying to set the world on fire because it's doing that all by itself

if the wastegate wasn't lapped, i would highly suspect it to be leaking some if you can't develop more than 7 psi boost.  even with a larger turbo, they will spool but later in the rpm range depending on size.  its either that or you have a boost leak.  

don't forget to check that cloth line's connections.  over time they get hard and crack and leak boost.  mine actually fell off once and i lost a lot of power and the boost gauge showed 0 psi.  i cut off the end of the hose and re-attached it, and bingo problem solved.  

since the turbine is still spinning, EGTs go up and since there isn't enough boost pressure compensating, they will rise even higher than normal.  essentially its like having an exhaust restriction, due to the lowered efficiency.  the turbo pressures should be at a 1>:1 ratio for maximum efficiency.

The wastegate valve might have been lapped or at least should have been,  I just wantd to do it to make sure but the way those damn actuatos are made you can't get things apart unless you saw the top off which I did on an old one just to see how it was put together.  I drilled and tapped the manifold elbow  that connects it to the turbo and installed a brass fitting there for the boost gauge line as I suspected these could be a source of problems coming apart or leaking so I 'now that's a good seal there.

[Smokey Eddy]

my egt at 120-130km/h is about 700-800 maaaxxxx

I haven't burnt a full tank yet but im getting almost 40 mpg i think?

I put 30 litres in from dead empty, i've gone 300 km and the needles is between 1/4 and 1/4. on the fuller side of 1/3 i guess you could say.