305 vs 6.2L diesel

[CyberSniper]

Yes, i can. As soon as the glow plugs stop cycling i put her in gear and drive away. Normally takes less than 30 seconds, a lot less.

I love your LS2 comment, lets compare something made over 20 years later with an IDI diesel.

As for fuel economy, at 230K miles, with bias ply 36's and 3.73's i still see over 20mpg.


I cant type anymore, im stopping while im ahead. I dont know what to adress next without my head exploding, some of you really are clueless, no offense.

I could be wrong, but I've never seen a 6.2L take off 30 seconds after stepping in the door when it's 10° outside.

You pulled the fuel injected "run on any angle" and "no 350 makes what a 6.2L does" cards. I proved you wrong. I noticed you didn't even touch the TPI 350.

Yes, diesels get better fuel economy than a carbureted motor of the same size. Duh. Add multiport fuel injection, modern engine design, and a diesel doesn't look nearly so good. I bet with 36s and 3.73s and your 20mpg the only thing it passes is the gas station. The only claim to fame the 6.2L has is its fuel economy. It isn't a bad wheeling motor because of its low-end torque but when you compare it to an injected smallblock it doesn't look as good. I'd have me a 2wd 6.2L pickup for tooling around in... but that's about as big of a purpose I see for one. You simply can't get enough power out of it.

 

[grape]

As far as other people and forced induction with a gasser... GM has been using them for 20 years now. So has Ford. Depending on the computer, you might not even have to do anything to go forced induction. It can be cheap as well... everyone knows about the twin turbo 302 setup that costs $3500. But that's a gofast setup. You need a whipple or a roots to get low-end.

I'd like to watch you guys try to dial in a Gen VII dfi on a turbo'd gas engine, even if it had the closed loop wideband that built a target air/fuel map, I'm betting there isn't one of you here that could make one run. The whipple and roots at low end are going to get there ass destroyed by a turbocharger system designed correctly that is at full boost by 2500 rpm on a gas engine. You guys do realize that a blower isn't at max velocity untill the engine is at max rpm right.............use your brain.

 

[PhoenixZorn]

no where in my original post did I say anything about a stock 350... I said a 300HP 350... what I neglected to say was that said 350 has forged pistons, heads, valves, etc... These parts plus a decent low range turbo charger for a v8 application can be had for under the price of a stock NEW 6.2L Diesel...

As for where I got my info, it came directly from the Banks website... and their MSRP for their built 350 twin turbo setup is not 50,000... it's 35,000... I said nothing about using the banks motor... I said a 300 hp starting mark on a 350. Which with forged parts, can easily handle the 30 lbs of boost you'd be puting into it with a twin turbo setup.

So, yes... 15lbs of boost effectively doubles the outbut of a small block v8 that is properly set up. I never said it would be a good thing to drop a turbo on a stock engine.

Stall on a turbo is exactly what it sounds like... if you have 2 turbos of the same size, you need not worry about it... but 2 turbos of the same size are not as effective for a wide power band engine (Corvette for instance) as two turbos of different sizes. The smaller turbo will kick in at lower RPMS and the big one will kick in at midrange, because it requires more exhaust pressure to get the bigger turbine spinning. That is called Turbo Lag... your turbo charger needs to wind up, and can't do that until there is enough exhaust behind it to push the turbine. The smaller the turbo, the easier it is to turn it.

 

[BlueBlazer]

Have you wheeled with both engines CyberSniper?

 

[Emmettology 101]

Yes, diesels get better fuel economy than a carbureted motor of the same size. Duh. Add multiport fuel injection, modern engine design, and a diesel doesn't look nearly so good. I bet with 36s and 3.73s and your 20mpg the only thing it passes is the gas station. The only claim to fame the 6.2L has is its fuel economy. It isn't a bad wheeling motor because of its low-end torque but when you compare it to an injected smallblock it doesn't look as good. I'd have me a 2wd 6.2L pickup for tooling around in... but that's about as big of a purpose I see for one. You simply can't get enough power out of it.

I disagree when you talk about the modern engine design and EFI.... Rene is getting 16+mpg(didn't go back and read to get actual figures) out of a stock J-6.2 diesel in a rig that runs 39.5" tires.... If he were to drop to stock the engine/rig is capable of 20+ mpg..

If you take a stock modern design efi engine and similar rig, we'll say an '02 Yukon with a 5.3. Similar size rig(other than the 4 doors) with a modern efi engine. Best this vehicle has gotten is 13mpg... We're talking a bone stock Yukon.... And that mpg was mostly highway mileage.

I personally dont think you'll get your SBC into the mpg range of a diesel...

 

[grape]

no where in my original post did I say anything about a stock 350... I said a 300HP 350... what I neglected to say was that said 350 has forged pistons, heads, valves, etc... These parts plus a decent low range turbo charger for a v8 application can be had for under the price of a stock NEW 6.2L Diesel...

As for where I got my info, it came directly from the Banks website... and their MSRP for their built 350 twin turbo setup is not 50,000... it's 35,000... I said nothing about using the banks motor... I said a 300 hp starting mark on a 350. Which with forged parts, can easily handle the 30 lbs of boost you'd be puting into it with a twin turbo setup.

So, yes... 15lbs of boost effectively doubles the outbut of a small block v8 that is properly set up. I never said it would be a good thing to drop a turbo on a stock engine.

Stall on a turbo is exactly what it sounds like... if you have 2 turbos of the same size, you need not worry about it... but 2 turbos of the same size are not as effective for a wide power band engine (Corvette for instance) as two turbos of different sizes. The smaller turbo will kick in at lower RPMS and the big one will kick in at midrange, because it requires more exhaust pressure to get the bigger turbine spinning. That is called Turbo Lag... your turbo charger needs to wind up, and can't do that until there is enough exhaust behind it to push the turbine. The smaller the turbo, the easier it is to turn it.

dude, you are seriously lost. do you think 15 lbs of boost with a to4e 50 trim is the same amount of air as 15 lbs with a t76. you can't say x boost will make x power on an engine. I've made more power with less boost on the exact same engine by changing the inlet wheel only and fuel to match the extra air.

 

[Pookster]

Acutally, when you equally add modern design to both... diesels look EVEN BETTER. New for new, you'd have to have, a Factory crate motor with TPI- Wiring harness, computer, etc. have you seen the price of a motor from GM parts direct with what you are looking for? The Eldebrock TPI conversion is over 1 k already. Find a factory motor with forged parts. I think price wise, the gas motor costs more, since they were not orginally designed for turbo's

The new diesels, which I wont get into, knock the PANTS off any production gas motor. So when you apply technology to both, you'll see there are gains in both, but not in the same way.

Can you take off in 30 seconds in 10 degree weather? You could. Some say you even SHOULD because a diesel thermally doesnt produce enough heat at idle. Someone else can chime in, but I think the dodge cummins manual says that you can drive away as soon as you have good oil pressure. Me personally, I prefer to idle for 2 minutes with any motor.

Its not that I dont like gas motors- I think they have their place, but the extra fuel economy is definately one of the #1 perks i like.

 

[PhoenixZorn]

dude, you are seriously lost. do you think 15 lbs of boost with a to4e 50 trim is the same amount of air as 15 lbs with a t76. you can't say x boost will make x power on an engine. I've made more power with less boost on the exact same engine by changing the inlet wheel only and fuel to match the extra air.

That's a valid point... but you are talking about turbos on the opposite ends of the spectrum... While they are not designed for this application, compare a Garrett T3 and T4 turbos... they will behave as I described in my above post... the T3 engaging and provinding boost in the lower RPM ranges, and the T4 proving power later in the middle and high RPM ranges. Both are equally capable of providing 15 lbs of boost, but they behave differently because of the turbine and inlet wheel sizes. Yes, both will produce a different horsepower gain because of their sizes, but they will do what they are designed to do.

If you can't find a GM engine with forged parts for under $3000, you are looking in the wrong places... A decent twin turbo setup can be had for under $1500, so you are back at the $4500 price tag of a new 6.2. Yeah, if you want 1100hp in a street legal application, go to Banks... but you don't need to buy their awesome stuff to get 900hp out of a 350.

 

[BlueBlazer]

Dude, you know not what you are talking about, please do not contribute any more of your useless, incorrect facts to this thread. A 6.2 does not cost 4500 bucks, a twin turbo system for a 350, unless pieced together with used parts is not only 1500 bucks, and your knowledge of turbos is minimal at best, so you shouldn't be giving advice about them and their operation. Regardless, this discussion was supposed to be about a 6.2 versus a 305, which you and cybersniper and dirtwarrior have managed to take way off track with discussions of TPI 350s and turbos and the like.

To the original poster, the 6.2 will make you much happier. I have wheeled a couple rigs with small blocks and my personal rigs have all been 6.2s. The only place the diesel loses out is in the mud, but if driven right with good tires, the difference isn't too bad. The crawlability of the 6.2 and other diesels is second to none compared to any gas engine. 1000 rpm and below no gasser can touch a diesel, so, especially with a manual trans, driveability on the trails with a gas engine sucks because you are constantly having to slip the clutch to get moving.

 

[dirtwarrior17]

Actually the TD 6.5's only came in 93 and 94... the rest were upgraded NA. At least thats what the manual says.

Rene: I know a gas engine won't last as long as a diesel nobody is questioning that. but a low boost supercharger-around 5-7 psi will get 200K miles out of it no problem. Hell i used to know a kid with 300,000 miles on his original 350 in a 1/2 pickup and it still had enough grunt to spin the rear wheels on pavement(I know those things are light as hell)

post up your dyno sheet if you get a chance...

your saying a stock 6.2 put down another 100+ ft lbs than gm rated it at?

Acutally, when you equally add modern design to both... diesels look EVEN BETTER. New for new, you'd have to have, a Factory crate motor with TPI- Wiring harness, computer, etc. have you seen the price of a motor from GM parts direct with what you are looking for? The Eldebrock TPI conversion is over 1 k already. Find a factory motor with forged parts. I think price wise, the gas motor costs more, since they were not orginally designed for turbo's

The new diesels, which I wont get into, knock the PANTS off any production gas motor. So when you apply technology to both, you'll see there are gains in both, but not in the same way.

Can you take off in 30 seconds in 10 degree weather? You could. Some say you even SHOULD because a diesel thermally doesnt produce enough heat at idle. Someone else can chime in, but I think the dodge cummins manual says that you can drive away as soon as you have good oil pressure. Me personally, I prefer to idle for 2 minutes with any motor.

Its not that I dont like gas motors- I think they have their place, but the extra fuel economy is definately one of the #1 perks i like.

Nobody said anything about the new diesels. I was saying a 6.2 and a 6.5 turbo vz a supercharged 350 and 454.

We all know the new diesels will outpull gassers hands down... add a programmer to a new duramax and you get another 100 hp and 250 ft lbs of torque.... a banks kit and you'll see another 200 hp and 350 ft lbs of torque. once you get into that kind of power your right up there with semis-no sh$t. same torque as em but with another 400 hp more than the semi.

to the original question.... a stock 350 compared to a stock 6.2... the answer is personal preference. nobody needs anymore power than a stock 350. I have already posted about the 305 vz 6.2( 6.2 all the way) but if you can find a cheap 350 i would snatch it up... you can easily gain another 65 ft lbs with a cam intake and carb. Some guys say you can turbo the 6.2 for that much but i find that real hard to beleive. the power between a modded 350 and a 6.2 is very comparable( at low rpms) except the gasser will give you another 100 hp over the diesel with very comparable torque numbers assuming you get the right cam.

 

[BlueBlazer]

once you get into that kind of power your right up there with semis-no sh$t. same torque as em but with another 400 hp.

 

[grape]

That's a valid point... but you are talking about turbos on the opposite ends of the spectrum... While they are not designed for this application, compare a Garrett T3 and T4 turbos... they will behave as I described in my above post... the T3 engaging and provinding boost in the lower RPM ranges, and the T4 proving power later in the middle and high RPM ranges. Both are equally capable of providing 15 lbs of boost, but they behave differently because of the turbine and inlet wheel sizes. Yes, both will produce a different horsepower gain because of their sizes, but they will do what they are designed to do.

If you can't find a GM engine with forged parts for under $3000, you are looking in the wrong places... A decent twin turbo setup can be had for under $1500, so you are back at the $4500 price tag of a new 6.2. Yeah, if you want 1100hp in a street legal application, go to Banks... but you don't need to buy their awesome stuff to get 900hp out of a 350.

I'm not going to be an asshole, so I'll help you guys try to figure out what you are trying to talk about. T3, T4, and T6 are family's of turbocharger exhaust wheels only. When they are in the same family the mounting demensions of the exhaust housings stay the same, yet for each family there is 3 sometimes 4 different size exhaust wheels. On the other end of that shaft you can place just about any inlet wheel you choose to make power for. There are literally hundereds of inlet wheel designs and sizes to match with about 8 total exhaust wheels.

saying you have a t4 turbocharger is like saying you are lost in the northern hemisphere and then asking someone which country you are in

a t76 and a t04e 50 trim can both be placed with a p-trim T04wheel, or a stage II T3 wheel.

 

[dirtwarrior17]

??? you dont' beleive me?

stock numbers on a dmax are 595 ft lbs of torque...

banks system 350 ft lbs

programmer 250 ft lbs

do the math.

semis have around 1300-1500 ft lbs with about 350 hp...my uncle owns his own 2002 big rig and can attest to these numbers.

 

[grape]

Actually the TD 6.5's only came in 93 and 94... the rest were upgraded NA. At least thats what the manual says.

why don't you open the hood on a 95- 2000 chevy or gmc diesel and see if you don't find the same style turbocharger hanging off the passenger side of the engine.

 

[dirtwarrior17]

because im not going to go door to door asking if i can pop their hoods lmfao..

seriously... how the hell would gm screw up their manuals like that?

Whos right here? did the td only come in 93-94 or is my manual full of sh$t again?

 

[joez]

Actually the TD 6.5's only came in 93 and 94... the rest were upgraded NA. At least thats what the manual says.
.

I said i was going to stay out of it, but this was to damn good to miss.

Once again your ****ing manual is not the be all and end all for information like you think it is. The 6.5 TD started in '92, 92 was a crossover year so you can find both 6.2's and 6.5's in both turbo and N/A trim. 92 and 93 6.5 TD's were pure mechanical still, with the same DB2 injection pump that the 6.2's used. In 94 they became computer controlled, and stayed that way until 2000. No N/A motors were put in pickups after '94, only optional in vans(AFAIK) and available in the Hummer, unless you are talking about marine applications, which both were available.

Stop talking about things you have no clue about.

 

[dirtwarrior17]

lmao chill.... damn sorry for listening to a gm manual... bahahahahaha. you want me to go around and question everything in there or what...

your playing with fire on that last sentence...but i don't want to screw this thread up any further than the 3 pages that went off topic... find me a quote. YOur gonna have some trouble unless you go back a couple months.

Stop talking about things you have no clue about.

Ditto.

 

[Emmettology 101]

??? you dont' beleive me?

stock numbers on a dmax are 595 ft lbs of torque...

banks system 350 ft lbs

programmer 250 ft lbs

do the math.

semis have around 1300-1500 ft lbs with about 350 hp...my uncle owns his own 2002 big rig and can attest to these numbers.

You're arguing diesel tech/numbers with someone who works for CAT(Blue Blazer)... :histerical:

 

[grape]

I've got a quote..................I said it back a few pages

I'll race any gas engine built by any of the brain surgeons who have posted in this thread against my junky ol'e 6.5 turbo set up that I built myself. After we get done racing, we can then chain them together.

 

[dirtwarrior17]

so because he works for cat he knows all diesels numbers even though he probly works on tractors? If its not 1300 - 1500 then thats false advertising... so what is it then?

I can't remember who made his rig but do a little research and you'll see thats where most semis fall.