The Only 3300 lb. Buick V6 in the 8s using...

[Dusty Bradford]

Yes. I would agree that those items helped a lot. You've been very well aware for a long time now that obtaining better than 1:1 was an important goal of mine. I think you finally figured that out in my tuned turbo exhaust manifolding thread in the fabrication section.

The advantage of using methanol fuel goes without saying. :biggrin: Although, racing gasoline manufacturers will argue you to death that advances in racing gasoline will yield similar or better results to using methanol fuel.

I figured out why you chose the 91mm..yes. I've known of the benefits of lowering back-pressure for a long time. But this goes back to the turbo manufacturers. When I'm limited to a turbo size my hands are tied but the turbo design has come a long way in the past few years.

I'm well aware of what the racing gas companies can claim but the track results prove otherwise. Especially when you throw in the really high powered ignition systems available now.

 

[Fryguy]

It is like comparing superchargers, an F3 Procharger is way more efficient than a D1, but then you'll have guys saying that a D1 is more suited for engines making x amount of horsepower and it's better on the street, which is nonsense. Guys now are running turbo wastegates on the intake tract of their centrifugal supercharger setups so they can control the amount of boost being applied (as opposed to relying on pulley size), then stuffing the largest supercharger that they can get on there and pullying it up. Doing that both maximizes and controls that power throughout, making the whole menu on Procharger's website of varying compressor setups being completely irrelavent, which is why you will never see them come out with a wastegate for a supercharger, because then you would only see one type of supercharger being sold, the biggest one....

Just for laughs I copied and pasted this post and sent it to procharger tech support. I thought for sure the response would be hilarious. Here it is, verbatim from their tech department:

"The person that posted that has no clue what they're talking about. How much
sense does it make to put a blower that takes 500-600 HP just to spin on a
300 HP engine? Your car would be slower than it was before the blower was
added. People do install blow-off valves to control boost, but in order not
to hit a point of diminishing gains, they still start off with an
appropriately sized blower. "

Street Lethal Keyboard Racing, you are a fountain of knowledge

 

[Alky V6]

I figured out why you chose the 91mm..yes. I've known of the benefits of lowering back-pressure for a long time. But this goes back to the turbo manufacturers. When I'm limited to a turbo size my hands are tied but the turbo design has come a long way in the past few years.

I'm well aware of what the racing gas companies can claim but the track results prove otherwise. Especially when you throw in the really high powered ignition systems available now.

That brings up another point about my setup. I'm using an old, outdated wastespark system, with no extra spark enhancement boxes. Yet, I'm still seeing the advantages of using methanol fuel over gasoline.

 

[Alky V6]

Dusty. I have a question. Are the fellows that are using twin turbos typically seeing better than 1:1 on the exhbp to intbp? Or, are they simply seeing closer to 1:1 than a single turbo app, but still over 1:1?

 

[Alky V6]

Just for laughs I copied and pasted this post and sent it to procharger tech support. I thought for sure the response would be hilarious. Here it is, verbatim from their tech department:

"The person that posted that has no clue what they're talking about. How much
sense does it make to put a blower that takes 500-600 HP just to spin on a
300 HP engine? Your car would be slower than it was before the blower was
added. People do install blow-off valves to control boost, but in order not
to hit a point of diminishing gains, they still start off with an
appropriately sized blower. "

Street Lethal Keyboard Racing, you are a fountain of knowledge

I can see the point with superchargers. But turbos is just a little bit different.
I remember when I was first putting my specifications for my project together and I called Kenny to get advice on what turbo to run. He knew I was going to use nitrous. He felt I would just end up blowing something up. For whatever reason, at the time, he was not real comfortable with using nitrous on a turbo Buick. Most likely because of all the knuckle heads that were carelessly throwing a nitrous system on their car and blowing their shtuff up. On top of that, he tried to get me to use a smaller turbo than the 70mm which I was planning to try first. This was back in the mid to late '90s. May have even been the early '90s. Anyway, a long time ago. That was the last time I asked for advice from anyone.

 

[Street Lethal]

Just for laughs I copied and pasted this post and sent it to procharger tech support. I thought for sure the response would be hilarious. Here it is, verbatim from their tech department...

That is your factual proof lmao? That proved absolutely nothing. You are as clueless, as you are useless. I think that special sauce is starting to take it's toll on your brain lol. Who was that five dollar an hour tech guy that you spoke to, does he or she have a name, or were they just a figment of your imagination? I will gladly invite the more than credible Job Spetter from Turbo People to show just how pathetically ignorant your 1-800 "tech guy" truly is. Take that Big Mac out of your mouth there burger boy, and learn something for once in your life...

 

[Street Lethal]

When you take a 427ci small block with a 106mm making 35psi and 70psi back pressure. Replace the 106mm with twin 88's making the same 35psi. The 200hp gain doesn't come from the compressor side making colder air...it comes from dropping the back pressure from 70psi to 40psi.

Dusty, using just one turbo in the example, I can see how the loss of 40-psi backpressure would possibly help gain 200hp averaged power across the board as opposed to actual peak, but how would it make 200hp over the already established peak horsepower number at 35psi? The boost gauge is just a pressure reading, so how can 200 hundred more horsepower suddenly be consumed at the very same boost pressure level, with the very same turbo, just by decreasing backpressure? Where is the extra air coming from at 35psi of boost pressure with just the loss of 30psi backpressure to add that much horsepower, that is like an additional 15psi within that same 35psi out of nowhere? By this example of reduced backpressure, all I see is boost coming in quicker, with potentially more RPM to take advantage of later. I'm trying to understand what your saying but it is a little hard to see...

 

[KL Mallender]

Your still looking at the wrong side of the engine:biggrin:

The 91mm will still make more hp at 12psi. Not because of compressor efficiency but because the pressure on the exhaust side is lower. Sure there is a little hp difference by running the compressor side more efficiently but we're talking minor...exhaust back pressure is major.

Roll your motor over with the plugs out of the heads. Now put 40psi of pressure on 1 cylinder and see if you can turn it over. This is the pressure your piston is working against to push the exhaust out of the cylinder. That is power.

Without questioning further, Dusty has spent time and effort chasing the ghost that taunts, Don has also chased, and tracked down said "ghost", has he found what awaits those that are dillegent in their pursuits, the immediate payoff is usually a fryed combustion chamber when this phantom rears it's head looking to see if you are paying attention, For most, a well cooked longblock only yells back to not do that to me again, where most just back things off to appease the "Turbo Gods" in not asking them for another sacrifice, a "Technician" looks at the broken/bent/mutilated remains and is never quite the same afterwards, he'll typically refrain from pushing ahead further untill he comes to grips "why" the previous endevour failed in such a horrific manner, that was NOT the plan. It all made perfect sense before the fatalisic final run, which will be forever engrained in their head, they were sure, they were confident, everything points to this, and then,.......The ultimate WTF?. These trials happen exactly as described more times than "ANY" man can tollerate sometimes, enough that scrapping everything is easier than trying to figure out "what" went wrong or even "why", this experimenting gets expensive quickly, not just monetarily, but when you've "spent" yourself totally dry, you land abruptly. You will never forget this level of emptyness......ever.

For me, Donnies original thread title was a pure taunt, I can see how it may unhinge some people from the "Assumed" norm today, it could be that Donnie is looking for a little support from the majority here(ie: Small valved, production base guy's) that are attempting the same, and I gotta say I'm dissappointed by some reponses from the Stage 2 group. It is what it is for thread counts, I doubt few of the original target audience is even paying attention anymore, so, I end my involvement with this thread today.

Kevin.

 

[Street Lethal]

For me, Donnies original thread title was a pure taunt, I can see how it may unhinge some people from the "Assumed" norm today, it could be that Donnie is looking for a little support from the majority here(ie: Small valved, production base guy's) that are attempting the same, and I gotta say I'm dissappointed by some reponses from the Stage 2 group. It is what it is for thread counts, I doubt few of the original target audience is even paying attention anymore, so, I end my involvement with this thread today...

That is exactly how I see it Kevin. Donnie definitely used this thread to get people to think out of the box as to why his setup is able to deliver. However, everyone jumped all over him because of it. Rather than have everyone come together, it became a battle of ego's. I too am unsubscribing, although I'd like to thank Don, yourself, Dusty, Bitt and everyone else who made this discussion positive. I left my ego at the door, spoke with the guys that know how to get things done in the turbo world, and walked away with way more knowledge than I had, and for that I am grateful to you guys. In the end, everyone here are Buick guys, so stop letting the little differences cloud your vision. Thanks again Don, this thread was extremely informative. Just wish all the nonsense was left out of it...

[video=youtube;VneQFkT2WPQ]http://www.youtube.com/watch?v=VneQFkT2WPQ[/video]

 

[Fryguy]

That is your factual proof lmao? That proved absolutely nothing. You are as clueless, as you are useless. I think that special sauce is starting to take it's toll on your brain lol. Who was that five dollar an hour tech guy that you spoke to, does he or she have a name, or were they just a figment of your imagination? I will gladly invite the more than credible Job Spetter from Turbo People to show just how pathetically ignorant your 1-800 "tech guy" truly is. Take that Big Mac out of your mouth there burger boy, and learn something for once in your life...

HAHAHHAHAHAHHA!!! Man I don't often truly "laugh out loud" at the computer, but this one did it for me! Thanks!

The guy didn't actually sign the email, but here is the reply address: techserv@procharger.com

Take care racing the Lethal Keyboard!

 

[Alky V6]

Thanks Kevin, and Street Lethal for participating, and at times having my back. My intent in starting any thread is certainly not to look for support or acceptance. Although, on this thread, I did have some support for a change. Felt good to see others with vision beyond the normal Buick TR box.
Thanks to Dusty, Turbo Bitt, Lazaris, and anyone else I may be forgetting at the moment for putting in your share of positive input.
My intent in starting most threads is to get people thinking in ways other than what they're used to. If that offends some, then so be it. I can take the flak. It is rewarding to see others pick up some new bit of information that might be useful to them in some way. I will usually pick up things from the exchange of ideas, myself.
Sorry if the methods I use sometimes seems rank to some. I find that sometimes when you rattle cages, some interesting stuff can fall out. It certainly can bring out some interesting personalities in some people. Interesting stuff to say the least. All in fun, though.

Good night everyone, and may I wish everyone the Happiest of Holidays.

 

[RIFF RAFF]

Don.. Dont go falling off the face of the earth....it's flat ya know .. Fcol !! Im gonna go with 2, 105 mm and spool them with aquanet & dustoff injection .. Good luck ..

 

[baadgn]

Good night everyone, and may I wish everyone the Happiest of Holidays.

Ditto

 

[Dusty Bradford]

Dusty. I have a question. Are the fellows that are using twin turbos typically seeing better than 1:1 on the exhbp to intbp? Or, are they simply seeing closer to 1:1 than a single turbo app, but still over 1:1?

Just about every single turbo application is ran at 2:1. The newer HP series turbos from Precision get this down through engineering. For example my old 94mm made 27psi and had 55psi back pressure. Pushing it harder than this slowed it down. The new 94's will make 30# at 40psi back pressure so they make more power.

The twins will also depend on who the manufacturer is. We removed a set of turbonetics Y2K 91's and replaced them with Precision Pro mod 91's. The Y2k was at 1:1 at moderate boost levels and over 1:1 at high boost levels. The Precision unit's were much lower than 1:1 at moderate boost and still just below 1:1 at higher boost levels. The car also picked up 10mph at the 1/8.

 

[Dusty Bradford]

Dusty, using just one turbo in the example, I can see how the loss of 40-psi backpressure would possibly help gain 200hp averaged power across the board as opposed to actual peak, but how would it make 200hp over the already established peak horsepower number at 35psi? The boost gauge is just a pressure reading, so how can 200 hundred more horsepower suddenly be consumed at the very same boost pressure level, with the very same turbo, just by decreasing backpressure? Where is the extra air coming from at 35psi of boost pressure with just the loss of 30psi backpressure to add that much horsepower, that is like an additional 15psi within that same 35psi out of nowhere? By this example of reduced backpressure, all I see is boost coming in quicker, with potentially more RPM to take advantage of later. I'm trying to understand what your saying but it is a little hard to see...

It's not consuming 200 more hp worth of air and fuel, the power is making it to the wheels. I gave you an example of using air on your engine to duplicate backpressure. Roll your engine over by hand with all the spark plugs removed. It's fairly easy. Now apply 40psi of air to just one cylinder and see if you can rotate the engine. I bet you break the bolt off in the snout of the crank before the engine rotates. There is your extra power. That pressure in the exhaust system is the parasitic drag of a turbo engine. Just like an exhaust brake on a diesel engine.

Now the engine will need more fuel. Not the full 200hp worth but it will need additional fuel. I can see the difference in the VE table. None of us can really grasp the dynamics of everything going on in the cylinder at 7500 rpm with all this pressure in the intake and exhaust so explaining how and why is very difficult.

 

[Alky V6]

Reducing exhaust backpressure reduces engine pumping work hp losses. Also, increases VE. How much of an increase in VE that is ultimately realized is dependent on how the other tuning parameters of the engine (manifold tuning, camshaft specifications, etc.) are configured to take advantage of the lowered exhaust backpressure.

Engine pumping work hp losses can be looked at in the same way that you would look at drivetrain hp losses. If you can find a transmission that is more efficient at transferring power through it, you will end up losing less of the hp that was generated by the air/fuel intake charge. More hp will make it to the ground. By reducing pumping hp losses, you will save hp that would have been lost through excessive engine pumping work.

With a good engine analyzing sim, you can see all the different types of hp losses that occur with an engine. HP lost through the cooling system, mechanical losses, frictional losses, pumping losses, etc. The hp that is seen as lost due to pumping work can be reduced by making changes to the exhbp to intbp ratio. That can actually be witnessed with the EA sim. The sim I use actually shows that I am losing negative numbers of hp due to pumping work losses. Negative numbers means I am gaining hp from engine pumping work, not losing. That shows just how important reducing exhaust backpressure can be.
More important, obtaining better than a 1:1 exhbp to intbp ratio can net you more hp, not less when strictly looking at potential engine pumping work hp losses.

Dusty was on the right track about the gains that can be had with reduced exhaust backpressure. I don't think he realized just how much advantage there is with reducing exhaust backpressure.

 

[Alky V6]

Just as turbocharging is a great way of recovering hp that is lost in the form of exhaust heat, reducing exhaust backpressure is a way of recovering hp that is lost in the form of engine pumping work. Reduce the exhaust backpressure to a favorable enough ratio, and you end up creating hp, not losing it, through engine pumping work alone.

This is why achieving 'CROSSOVER', which is having the exhaust backpressure at a lower level than the intake boost pressure, with a turbocharged engine is considered to be THE 'Holy Grail' of turbocharging.

 

[Street Lethal]

Just as turbocharging is a great way of recovering hp that is lost in the form of exhaust heat, reducing exhaust backpressure is a way of recovering hp that is lost in the form of engine pumping work. Reduce the exhaust backpressure to a favorable enough ratio, and you end up creating hp, not losing it, through engine pumping work alone....

What threw me off was the terminology being used, as it is a little more understandable for me to say that reducing exhaust backpressure actually releases restricted horsepower that is already there, it is just being restricted because of the exhaust to intake ratio, not necessarily creating additional horsepower over what the turbo and engine are actually capable of. We can dyno an engine with a certain setup and achieve x amount of horsepower, apply 15 pounds of boost and that figure just about doubles (give or take a few horsepower). When I hear that reducing backpressure would create 200 more horsepower through the turbo alone, my first reaction is how on earth is that possible because we're not burning more fuel at the particular psi used in the equation, we're just picking up two hundred more horsepower throughout the RPM band, collectively (averaged), but this pickup in horsepower due to reduced exhaust pressure also raises naturally aspirated horsepower at the same time, it has to...

 

[Dusty Bradford]

Dusty was on the right track about the gains that can be had with reduced exhaust backpressure. I don't think he realized just how much advantage there is with reducing exhaust backpressure.

2-3 years ago I did not realize it until I started monitoring it and tuning more and more cars. Now I hate to tune a car that doesn't monitor it. I do know how much there is to gain which is why I have stated numerous times this is why you can run the et's you do with your heads. I don't think many others realize just how much power an engine can gain. The only reason most of us class racers can't capitilize on it is because of the limits of the class, in order to have parity between all power adder types.

The new HP turbo's from Precision are making the rules makers go back to work because you now have 94mm turbo's capable of power it took a 106mm to accomplish just 4 years ago.

 

[Alky V6]

What threw me off was the terminology being used, as it is a little more understandable for me to say that reducing exhaust backpressure actually releases restricted horsepower that is already there, it is just being restricted because of the exhaust to intake ratio, not necessarily creating additional horsepower over what the turbo and engine are actually capable of. We can dyno an engine with a certain setup and achieve x amount of horsepower, apply 15 pounds of boost and that figure just about doubles (give or take a few horsepower). When I hear that reducing backpressure would create 200 more horsepower through the turbo alone, my first reaction is how on earth is that possible because we're not burning more fuel at the particular psi used in the equation, we're just picking up two hundred more horsepower throughout the RPM band, collectively (averaged), but this pickup in horsepower due to reduced exhaust pressure also raises naturally aspirated horsepower at the same time, it has to...

Yes! Yes! Yes! Like I stated earlier, if an engine is properly tuned to take advantage of the lower exhaust backpressure, a greater level of increase in VE can be realized.

As exhbp to intbp closes in on a 1:1 ratio, or BETTER, say a .90:1 ratio (my particular engine), the engine begins to act more like a naturally aspirated engine, and the tuning principles that would be used on a naturally aspirated 4 stroke engine begin to have larger effects. Just occurring at higher pressure thresholds.

The benefits of achieving crossover are twofold. You have HP increases due to increased VE, AND the little bit of hp that you're actually creating, and not losing from engine pumping work.