I would assume even though it said "stock" LT1 that it had either bigger injectors or an FMU..

And you guys can call BS if you want, but it is entirely possible. My home brewed twin turbo setup went from 276 RWHP to 405 RWHP with 6 psi boost. That is with a stock DFI timing curve and running safely rich, on a 95 deg Houston day. I also lose because of the T350/3500 stall and 31x16.5 rear tires, so in the average 4th gen, my setup should be good for any easy 450 RWHP, more with some tuning.

The motor was all stock, other than a 58mm TB, Hot Cam and 1.6 RR. All that was on it for the 276 N/A run also.

And when I took it all apart, the motor was in excellent shape. On 93 octane.

Oh, and it made 513 RWTQ @ 3500 rpm. Try that with a S/C and 6 psi.

 

I've seen the vids of this car making 553rwhp on 7 cylinders. Their claims are not bogus.

 

Man what a thread I posted. Numbers are proven I would have to say that turbos make more power over a supercharger. I just cannot beleive the power these things are making. I was going with a procharger but after reading about turbos you can defently get more power out of them. THE WINNER OF THIS THREAD IMO WOULD HAVE TO GO TO -----TURBO------

 

the LT1 had 30 lb injectors and a FMU, the motor however was stock, as was the pcm tune.

 

Atmospheric press = 14.7 psia (pounds per square inch absolute)
+
7psi = 21.7 psia

14.7/21.7 = .677

7 psi of boost is only 67.7% more than atmospheric pressure

 

Nitrous from the intercooler shot definitely made it into the intake tract.

Supposedly a common problem with the co2 intercooler sprayers, my buddies car lost power with the co2 ic sprayer activated , due to dilution of the intake charge (since co2 doesn't enhance combustion much ). It took quite a few tries at building a funky airbox/shield setup for the filter to prevent co2 from being ingested by the motor.
Might explain to an extent the crazy numbers.

The baseline dyno pull would have been made at a nice safe a/f ratio and the boosted pull would have been piston-holing lean, obviously. Not so good for the motor but good for power production in this case I guess .

 

On a T70 Turbo..... you conveniently left that part out.

 

AFR was dipping below 10:1 actually.



but it detonated from too much timing (stock tune) so death occured

 

I didn't mention any of the turbo sizes, that wasn't the question, the question is weather its physically possible, and obviously it is from all the examples.

 

Turbo size matters just as much as psi. 7psi from a T70 will flow more air per psi than say a T04E or T60... etc. at the same level of boost. Making a statment like "i made X amount of HP with Z amount of boost" is leaving out a very important part of the equation.

 

This is getting amusing. 14.7 + 7 = 21.7 very good. Now for the hard part ... 21.7 / 14.7 = 1.47 That is the 1.5 times number I alluded to in a previous post. I did some rounding up, didn't want to make things more complicated than need be. Now SmoknZ 14.7 psi is atmospheric, you add 7 psi to that and get 21.7 psi. If you want to refence that number (21.7) to % of atmospheric you must keep the original 14.7 as the denominator (sorry for the big word), that is the original reference point. Thus 21.7 /14.7 = 1.47

Now we are ready to make the jump to %, just times that 1.47 by 100 and you get 147%. My original premis was that it was not reasonable to expect more than 1.5 times the power you started with, assuming you supply 1.5 times the air. If you start with a bone stock LT1 that makes 260 rwhp at atmospheric pressure, and then supply that same car with 1.5 times the air, that would be 7 psi of boost, then the best you should see is 1.5 X 260 = 390 rwhp. Again, I have rounded that 1.47 up to 1.5 for simplicity.

By the way, where did you take grade 8 math?? I'm not letting my kids go to that school.


How about a plausible real world example?

6psi is 41% more than atmospheric, so 1.41 times 276 = 389, not too far off of the 405 rwhp reported, he may have gained a little from going lean on top, boost guage could have been a little off, point is that these numbers make sense.

To make 485 rwhp, starting with 260 rwhp, would require in the neighborhood of 13psi of boost. And in all likelyhood more than 13psi of boost, because parasitic losses do increase as power levels go up. That is unless you smoke crack cocaine, and in that dream world, everything is possible and makes absolute sence.

Hope this helps

LWM

 

Yeah I guess that really didn't make sence did it, 7 is half of 14 and how the hell could it be anywhere over 60%.

Don't worry my 8th grade school is a pretty far drive for your kids You have nothing to fear.

 

I know damn well it matters, but the question was only if it was possible or not.

 

LWM - I dont want to call you an idiot, but you are missing the points here that make those numbers possible. Firstly, on an lt1 with a turbo setup, you have "headers" or something to that effect, unless 100% stock manifolds are used. So that's important. Also we have a cutout working here. Headers and a cutout will pull the rwhp up without much effort. A turbo is an exhaust restriction, yes, but it is not as much loss as a supercharger with pulley and belt.

You preach flow losses - yet you cannot provide numbers for those losses. They are minimal at 7-10psi. Do they exist? Sure. But you're going to have more of a loss from taking an airfoil off the stock throttle body. 8psi is NOT something to worry about. Losses at that point are minor. Exist? Yes. But minor, no more then a few hp lost in the mix. But while we're on losses - that's from maximum. You act as if we're loosing something. We're pressurizing the intake manifold, which is a large cavity. Not only is a large cavity manifold (with short primaries) more ideal for a forced induction setup then N/A - but because the air follows such a short path anyway, it isnt a big issue. So we might be loosing 5hp do to flow losses from our maximum potential - which means that out of the 485rwhp, flow losses mean if we eliminated them we'd be at 490hp. Comon.

Also you seem to be forgetting the dynamic compression ratio bit. Do you have any idea how much of a difference it makes? Why do you think that cars with even 6-8psi blow apart with a proper tune?!?!! They detonate!! The dynamic compression is too high without adjusting the timing and is asking for trouble. Any supercharger company reccomends programming and boost retard. Neither wasnt used here. It's impressive to say the least that the motor didnt nuke sooner - but as I said, running an engine on the brink of destruction yields the best results... Why do you think race car engines dont last long? In this case they ended up going to far. You chant flow dynamics - but you havent really attacked the CFM and temperature issue. Do you understand the differences? Do you understand how psi is an irrelevant term when it comes to power compared to temp and CFM? Do you realize that running 7psi on a T70 lt1 then merely changing the turbo to a T88 can make more power at 7psi? Do you know why? I'm not going to tell you that you didnt graduate the 8th grade - but I am going to say if you're running 13psi or more through vortech's aftercooler that you're loosing a lot of power there. Do the calculations on it's volume and core. I talked to their very own techs and there is a reason they quote their numbers at 10psi only. You probably have a nice bit of flow loss considering you're pushing more CFM them a 350 will, for the same amount of psi. When I talked through the numbers with them, they were pretty sure putting anything more then 12psi through their own product was a bad idea for maximum power.

Your supercharger setup is loosing a lot of power from that belt too. Dont forget that. You're flagging BS on this, and its really starting to annoy me because you are quoting the same crap again and again "It's flow dynamics" then do the calculations and post them! Dont just try to preach without backing yourself up. I've seen crazy turbo setups do more dramatic stuff then this. Espicially considering Tiago even said that they used the ECU's full timing. Run your air/water on the dyno with a water temp of 100 degrees and log your IAT's. Now run the water at 10 degrees and check the IAT's. You'll see a sick improvement. Not even ice water can come close to the power of spraying liquid nitrous on the core. I dont know if you get that either, considering you have not made any mention of that or to the power gains.

I've seen better numbers. And LWM - I've seen a turbo 5.0L auto foxbody mustang push over 650rwhp on 14psi. And that's on 302cid instead of your 383. That was with an air/air intercooler and no nitrous, no co2, and pump gas. But because he was running a stock intake manifold those numbers must be BS. After all, your larger engine made less power AND you had an air/water intercooler. It must be BS. Totally. And the flow losses on manfold must have been horrible!!! Comon...

These numbers are possible, noting the power of turbos and then using max stock timing with boost and extremely low inlet temps. You do not know all the facts and neither do I. So until you do all the calculations and post them here, I'm going to tell you to put your flagpole away or stick it somewhere.

And if you're going to be so immatureas to go after someone's spelling or grammer, I'm going to have to tell you to grow the _ up. Everyone makes typos - and not everyone uses a computer 24/7. And not only that, I'm not going to go after your spelling errors in this thread or others - you are just as guilty my friend. I'm no college graduate, but after 4 college physics courses and Calc courses up to and not including Diff Eq - I still cant do all the compressor calculations and flow dynamics. I wont pretend to. I wont pretend to know what I'm doing with turbos compared to the guys that know more then I do and have never gone to college or even taken 8th grade math. Some of the pros know their stuff but dont have a piece of paper to prove it - but it changes nothing. I dont think you can do the calculations either, unless you've got handy access to both the flowbench and the metering equipment necessary to tell me exactly what the loss is for having 7psi in that intake manifold. Considering you're not there, you dont know what the full setup looks like, you dont know even what turbo was used, what the IAT's were, where the compressor was operating at on it's map, and what the ambient conditions were - you have no basis to flag BS. The numbers are a stretch, but possible. And like I said - do the calculations and put up the numbers why it cant work, or I'm just going to say you dont really know what you're talking about. You have yet to prove why they are BS.

Then realize how much power you could gain or loose from changing the timing curve and advancing the timing 6 degrees with 7psi in the manifold. Tell me how much power it will make. Tell me how much of an effect it will have to both the dynamic compression and the efficiency of the motor. Tell me why that car cant make that power. Tell me why it wont work. These numbers are possible considering we dont know everything.

EDIT: So can we please get this thread back on topic?

Turbos usually make more power when done right, but cost more. They are both harder to install and harder to tune. They are more of a headache for troubleshooting and have more chances of messing up your engine when something goes wrong (like if a vacume line breaks). More power can be had but it comes at a price.

 

Exactly, you are pressurizing the manifold, to according to the original post, 7psi, which is 1.5 times atmospheric, which makes for 150% more air in the manifold. I'm gonna give you ... no pressure losses through the intake, none, zero, nada ... following me?? The engine wasn't changed or modified. The most that intake will flow is ... 1.5 times what it flowed at 1 atmosphere. Unless of course you have some revolutionary theory on flow dynamics which states to the effect that doubling the pressure more than doubles the flow rate through an orifice (the runners/valves)??

Now we get to the part about chemistry, 1.5 times the oxidizer (O2 in the air), you can burn 1.5 times the fuel. You can make 1.5 times the RWHP and that assumes the perfect world scenario. 260rwhp X 1.5 = 390rwhp. Heck, I'll even go so far as to give you a few horsepower for the Turbo manifold, say 15, that gets you to 405. Not 485 at the wheels.

In my argument, I've assumed no change in timing, and no detonation. I have given away all parasitic losses. The power output numbers don't make sense.
The reason one turbo makes better power at the same psi, one is more efficient than the other on the exhaust side. (better match to the size of the engine).


FWIW, I see about 9psi of boost, at 6,200 rpm. I'm thinking the supercharger eats 50hp?? Mention of spraying nitrous on the core?? That wasn't mentioned in the 7psi scenario, it was mentioned in the 554 scenario. Please get your facts straight. And ... I can't run water at 10 degrees ... it's ice. Like I said before, I just assumed full stock timing. You put 1.5 times in, you get 1.5 times out. In my world anyway, but then again, I don't do crystal meth.

If you are running a bit of camshaft, and let the engine spin, at 14psi of boost, I'll believe 650rwhp.


What I said before, I'm giving up all the power losses through increased flow and increased drive train losses through friction. Have a closer look, I'm not even factoring in the turbo restriction. It's the simple 1.5 X air/fuel in = 1.5 X the power out type of thinking. He keeps the same timing. Is this math getting complicated?

And so ....

I'm thinking if you were to add 6 degrees of timing on top of 7psi, the engine would break. What possessed you to come up with that idea? ... don't answer that, I don't think I want to know ... I don't think I'm ready for that type of information.



EDIT: So can we please get this thread back on topic?
I'll agree with that. And I won't go after your gramar and spelling either

Hope this helps

LWM