gbentink Turbo Upgrade Users Thread (6 Viewers)

[SAM1HDT]

You might of just had more fuel, so it was giving you more boost, I don't think my cruiser is any where near 214rwkw. Probably not even 214rwhp haha.
How did you find low range with the 3.73's? I was running 37's with standard gearing and 1st low is a bit to high. Didn't really have a crawling gear.

 

[Locked79]

I had absolutely no problem with low range gearing. In saying that, it was never used as a rock crawler.

 

[ForealBoreal]

remember the autos run at a lower rpm compared to the manuals.

I'm running 2300rpm @ 100km/h on 255/85/16 and 12lb boost. H55F transmission and stock 4.1s

If I were to switch to a badboy I would be running 7-8lbs at the same speed. Works for me.

It boils down to what you hope to use your truck for.

3.7s would be the ticket but I cannot justify ripping into changing them for the cost of the parts and job alone. The cost could buy a lot of fuel. If I ever wrecked a ring a pinion, I would be going the 3.7 route.

The dream would be 3.7s and a 3:1 low range kit.

 

[SAM1HDT]

I just discovered marks 4x4 are doing 3.54 ratios for 80's now. What do you guys think they would perform like? I would need reduction gears for sure with them! But on road would be awesome I think.

 

[ForealBoreal]

Well what would that drop your Rpms vs 4.1 and 3.7?

 

[SAM1HDT]

3.54 1970rpm 100km/hr
2160rpm 110km/hr

3.73 2070rpm 100km/hr
2270rpm 110km/hr

4.10 2280rpm 100km/hr
2500rpm 110km/hr

All with 33" tyres. 35's would be ~130rpm lower on all of these.

 

[mudgudgeon]

3.54 1970rpm 100km/hr
2160rpm 110km/hr

3.73 2070rpm 100km/hr
2270rpm 110km/hr

4.10 2280rpm 100km/hr
2500rpm 110km/hr

All with 33" tyres. 35's would be ~130rpm lower on all of these.

Too low IMHO.
Puts your cruising rpm to close to your peak torque. Doesn't leave enough torque in reserve for pulling up a hill, or passing without dropping down a gear.

 

[mudgudgeon]

@ForealBoreal, out of curiosity, what do you see as a problem with 12lb boost at highway speeds?

 

[ForealBoreal]

@ForealBoreal, out of curiosity, what do you see as a problem with 12lb boost at highway speeds?

Well my turbo came with a 15lb wastegate. Turbo is good for 20lbs boost. 12lb on cruise with a max of 15, not much of a reserve. I ran the 15lbs boost for awhile until I intercooled, it's now on 20. The turbo is getting to much back pressure and I believe the added boost at cruise is slightly effecting my fuel economy as its allowing my fuel pin in my compensator to fuel more when it's not needing to. I also notice I lack power up top in the RPMs where I wish I had a little more steam.

The 1hz for me has enough power low end before the boost really turns on, and honestly I'm wanting the boost more up top at this point. I'll sacrifice a bit of spool up with the bigger turbo for greater efficiency, less back pressure and more boost

 

[ForealBoreal]

Too low IMHO.
Puts your cruising rpm to close to your peak torque. Doesn't leave enough torque in reserve for pulling up a hill, or passing without dropping down a gear.

What's the h150 or 151 cruise at rpm wise at 100km/h?

Yet again everyone's circumstances are different as well as their goals. I think 3.73s would be the ticket for me and a bad boy.
3.54s and a grunter ex would probably rock because it would lower the load on the engine thus creating a lower cruising boost...

 

[SAM1HDT]

Puts your cruising rpm to close to your peak torque. Doesn't leave enough torque in reserve for pulling up a hill, or passing without dropping down a gear.

Isn't that what lower gears are for? Extra power when going up hills and passing.
5th is for cruising down the road at 100km/hr or more.
I don't know, but if the engine was at peak torque, wouldn't it hold that speed better going up hills too?

 

[ForealBoreal]

I think you may have it backwards (don't roast me if I am wrong)

Yes lower gears would keep you at more of a power range depending on your engine/transmission and where this power and torque range is.

Lowering your gear ratio would be the equivalent of going from 4.11s to say 4.56s
Higher gear ratio would be 4.11s to 3.73s

 

[SAM1HDT]

Sorry I ment to lower gear numerically, as in changing down from 5th in to 4th or 3rd when going up hills or passing.

 

[IanB]

Well my turbo came with a 15lb wastegate. Turbo is good for 20lbs boost. 12lb on cruise with a max of 15, not much of a reserve. I ran the 15lbs boost for awhile until I intercooled, it's now on 20. The turbo is getting to much back pressure and I believe the added boost at cruise is slightly effecting my fuel economy as its allowing my fuel pin in my compensator to fuel more when it's not needing to. I also notice I lack power up top in the RPMs where I wish I had a little more steam.

The 1hz for me has enough power low end before the boost really turns on, and honestly I'm wanting the boost more up top at this point. I'll sacrifice a bit of spool up with the bigger turbo for greater efficiency, less back pressure and more boost

Could you not play with the pump tuning and tighten the pre-load a bit so it takes more boost to move the fuel pin to suit your highway cruising needs? At the same time, if the pin is adding fuel at that boost level, would you not require less gas pedal to maintain the cruising speed, thus cancelling things out anyways? I'm still a total noob at pump tuning, just done a bunch of reading on the subject so far, no real world experience.

 

[zipdoa]

So... based on what I've read from ForealBoreal, and based on the assumption that 50% of my driving will be city/hwy, I think I'm going to pull the trigger on the Badboy (not extreme). Since there's no apparent disadvantage to running high boost (my 1HDT is in the process of a complete rebuild, including injectors and IP), I'll shoot for 30PSI and try and get a good quality intercooler on at the same time.

Hopefully this will make for a satisfying hwy bomber but still be livable in the trails.

 

[mudgudgeon]

Isn't that what lower gears are for? Extra power when going up hills and passing.
5th is for cruising down the road at 100km/hr or more.

Yes, obviously this correct. But if you'rew cruising at too low an rpm, you'll be grabbing for lower gears sooner.

Maybe not a big issue with a torquey 1hd-t. In my 105 with NA 1hz,fitting larger tyres had me cruising at 2500rpm(previously around 27-2750 rpm), if I came to a hill and revs were dropping, I'd be downshifting before 2200rpm (right on peak torque ). That slight drop in rpm occurred far more often than you'd expect.
Larger tyres lowered cruise rpm, but you're at that rpm less due to down shifting. Economy went backwards

 

[ForealBoreal]

Could you not play with the pump tuning and tighten the pre-load a bit so it takes more boost to move the fuel pin to suit your highway cruising needs? At the same time, if the pin is adding fuel at that boost level, would you not require less gas pedal to maintain the cruising speed, thus cancelling things out anyways? I'm still a total noob at pump tuning, just done a bunch of reading on the subject so far, no real world experience.

Not really, with the boost comp you can essentially tune the low end, overall delivery and maximum fueling. When you get this tuned to a safe AFR it's one of those things you just leave alone.
Pedal travel feels the same really, even switching from 10mm to 12mm headed pumps. The 12mm pump wants to fuel more and boost more on cruise.

Gearing ultimately is the #1 thing that would get my goal but I am not willing to play with that as of yet. For now it's going to be playing with the turbo in 15,000km at my 200,000km service interval.

So... based on what I've read from ForealBoreal, and based on the assumption that 50% of my driving will be city/hwy, I think I'm going to pull the trigger on the Badboy (not extreme). Since there's no apparent disadvantage to running high boost (my 1HDT is in the process of a complete rebuild, including injectors and IP), I'll shoot for 30PSI and try and get a good quality intercooler on at the same time.

Hopefully this will make for a satisfying hwy bomber but still be livable in the trails.

Don't take my word as gospel, it's my opinion. If you are shelling out $2500 on a turbo from Graeme I would expect you would consult him with any questions you have and discuss what truly fits your needs.

If you are running a stock pump there is a limit to how much boost is actually doing you good. Yes it cools the air charge, If your pump is good for 90cc@1000st which odd the top of my head the 1hdt does you will tune your desired AFRs.

More boost won't equal more power. If you are running the boost comp set up correctly and at 22lbs you are getting 20:1 AFR full load, raising it to say 25lb to raise the AFR to around 22:1 for safety sake. If you were to run 30lb boost and the number rose to 28:1 well yes you have a really lean running truck but you are losing power you can be putting down.

Sorry if I am losing everyone here.

 

[Dougal]

Too low IMHO.
Puts your cruising rpm to close to your peak torque. Doesn't leave enough torque in reserve for pulling up a hill, or passing without dropping down a gear.

My three diesels are all geared higher than that. Two of them I have geared up intentionally.

My 4BD1T is ~1950rpm at 100km/h cruise (speed limit) and it climbs all road hills in that gear. Torque currently mid 500's (Nm)
My 2.0tdi is geared the same and once again climbs all road hills in that gear. Torque a bit less than 400Nm.
My 2.2tdi is doing about 1850rpm at 100km/h and with a turbo that's a fraction bigger than I'd like it does need changed down to 4th for hills. Torque is about 280Nm. But it gets better fuel economy than the 2.0tdi above.

Basically, if you've got enough torque then climbing road hills isn't an issue. But grabbing a lower gear for passing is something you do anyway (unless you're going to run out of rpm).

 

[Dougal]

Well my turbo came with a 15lb wastegate. Turbo is good for 20lbs boost. 12lb on cruise with a max of 15, not much of a reserve. I ran the 15lbs boost for awhile until I intercooled, it's now on 20. The turbo is getting to much back pressure and I believe the added boost at cruise is slightly effecting my fuel economy as its allowing my fuel pin in my compensator to fuel more when it's not needing to. I also notice I lack power up top in the RPMs where I wish I had a little more steam.

The 1hz for me has enough power low end before the boost really turns on, and honestly I'm wanting the boost more up top at this point. I'll sacrifice a bit of spool up with the bigger turbo for greater efficiency, less back pressure and more boost

Advancing your timing will reduce boost and improve fuel economy. If reducing drive pressure is the goal then a better turbine design will do it. Rather than a bigger turbine.

 

[Tapage]

Important note it's 1HD-T rely more on boost to low end .. compression number are lower compared to 1HZ and that's why IMHO a 1HD-T will be happy with low end boost ..