928 HP on the chasis dyno today - Thanks Otto

[turbobitt]

Where it comes to using a long duration, high overlap camshaft and taking advantage of pulse tuning with a turbocharged engine, say you don't know how to, and I'll believe you. Say you don't have the resourses to, and I'll believe you. Say you choose not to take advantage of pulse tuning with your engine project, and I'll believe you. But, don't say it's impossible to achieve with a turbocharged engine. That simply is not true.

Don't think you have the data to substantiate that. I can only speek to my 10 years of dyno testing for a company that prides itself on being a leader in valvetrain control, in the one of the worlds best dyno's, with some of the most sofisticated eguipment, and working with all of the major turbo manufactures.

Allan G.

 

[Alky V6]

Don't think you have the data to substantiate that. I can only speek to my 10 years of dyno testing for a company that prides itself on being a leader in valvetrain control, in the one of the worlds best dyno's, with some of the most sofisticated eguipment, and working with all of the major turbo manufactures.

Allan G.

I don't have all that there fancy equipment and all, but I do know how to read a pressure gauge. What would you think of an exhaust back pressure to intake boost pressure ratio of 0.90:1 at 28 psi boost? That is substantiated data right off the race track.

 

[Alky V6]

Here you go. A rare view into my dyno cell.
DRW / BUICK 91mm exhaust back pressure reading - YouTube

Notice how tame the engine is during the turnout off the track. Intake duration is over 240 @ .050". I just wish I could take this thing out on the street.

 

[Alky V6]

Don't think you have the data to substantiate that.
Allan G.

LOL. I should put that quote in my sig.
You're new to this site, aren't you. No. You've been here since 2002. Hmm. If you have any questions, let me know.

How many times have you actually tried to achieve pulse tuning with a turbo engine on that fancy dyno?

 

[Alky V6]

Allan. If you're looking for real hardcore data about pulse tuning of a turbocharged engine, contact Mr. Kinsler of Kinsler Fuel Injection. He has some hard core engine dyno data of a Buick V6 that he did work on many years back for you to study, if you don't trust my backyard style of dyno testing.

 

[Alky V6]

A recent video of the work I've been doing since the late 1990s to come up with data to 'substantiate my claims'.
Updating the Nitrous/Methanol ALS Tune-up. Large T6 91mm Turbo! - YouTube

And you're right. I am using very small heads. Imagine if I had started my project with stage II heads, like what you're using. As it is now, my tires are my limiting factor, not the heads.

 

[turbobitt]

I don't have all that there fancy equipment and all, but I do know how to read a pressure gauge. What would you think of an exhaust back pressure to intake boost pressure ratio of 0.90:1 at 28 psi boost? That is substantiated data right off the race track.

Don,
Without rehashing the info in my previous post, your not taking into account the pulses in the system but using the average reading to report this .90:1 ratio. Yes I have seen this type of PR, yes I also see that when using high speed instrumentation that the peek pressure is much higher than the average gage and occurs at undesirable times during the cycle.

I'm not here to debate your logic. What you have is obviously working to your satisfaction. I'm reporting on my results and giving feedback to what I think is desirable cam set-up for these power levels.

 

[bison]

.9:1 ratio means little on this engine since it isn't using nitrous or any other thing to increase spoolup. Running overlap with a pressure ratio like that could also blow the charge right out the ex valve at certain engine speeds and hurt power just as having to open and close the intake and ex valves sooner with backpressure ratios over 1:1. There is no need to play games here. The compressor is done. You could pulse tune till your blue in the face or advance or retard the cam and still can't remove the fact the compressor is done. It's like chasing after pennies when you could be going for dollars.

 

[turbobitt]

LOL. I should put that quote in my sig.
You're new to this site, aren't you. No. You've been here since 2002. Hmm. If you have any questions, let me know.

How many times have you actually tried to achieve pulse tuning with a turbo engine on that fancy dyno?

We have done several tests with manifold volume changes. Most of our data was collected using very complex engine simulation tools and then narrowed to a few dyno tests to back up the simulations.

Allan G.

 

[Alky V6]

Don,
Without rehashing the info in my previous post, your not taking into account the pulses in the system but using the average reading to report this .90:1 ratio. Yes I have seen this type of PR, yes I also see that when using high speed instrumentation that the peek pressure is much higher than the average gage and occurs at undesirable times during the cycle.

I'm not here to debate your logic. What you have is obviously working to your satisfaction. I'm reporting on my results and giving feedback to what I think is desirable cam set-up for these power levels.

It just tweeks me when people say that it's impossible to use a relatively high duration, high overlap camshaft in a turbo application. That's completely false. It's more involved to be successful doing it, but it's not 'impossible'.

 

[Alky V6]

.9:1 ratio means little on this engine since it isn't using nitrous or any other thing to increase spoolup. Running overlap with a pressure ratio like that could also blow the charge right out the ex valve at certain engine speeds and hurt power just as having to open and close the intake and ex valves sooner with backpressure ratios over 1:1. There is no need to play games here. The compressor is done. You could pulse tune till your blue in the face or advance or retard the cam and still can't remove the fact the compressor is done. It's like chasing after pennies when you could be going for dollars.

Not saying that Allan should pursue pulse tuning with his project. In fact, I would discourage it. I think that most people wouldn't have the patience to become successful at it. Stick with the easy methods.
I'm just correcting our friend here when he stated that running an appreciable amount of overlap was 'impossible' with a turbocharged engine. People that are reading this stuff don't need to be misled with statements like that.

 

[turbobitt]

It just tweeks me when people say that it's impossible to use a relatively high duration, high overlap camshaft in a turbo application. That's completely false. It's more involved to be successful doing it, but it's not 'impossible'.

Don,
You mention that you have over 240 @ .050 lift. I would not consider this high duration and sounds in line with what I have. When I say "high duration", I'm refering to high 250+ @ .050. with tigh lobe seperations in the 104-108 range at these durations. Again, this is all relative info.
Allan G.

 

[Alky V6]

We have done several tests with manifold volume changes. Most of our data was collected using very complex engine simulation tools and then narrowed to a few dyno tests to back up the simulations.

Allan G.

Every specification of my project engine was taken off many months of simulator work. The real world results far surpassed what the sim predicted.

 

[turbobitt]

Not saying that Allan should pursue pulse tuning with his project. In fact, I would discourage it. I think that most people wouldn't have the patience to become successful at it. Stick with the easy methods.
I'm just correcting our friend here when he stated that running an appreciable amount of overlap was 'impossible' with a turbocharged engine. People that are reading this stuff don't need to be misled with statements like that.

Pulse tunning has its place. I think that ultimate goal and efforts with pulse tunning would be faster spool-up with large turbine turbo's such as your BW 91. The ultimate goal with this pulse tunning is not going to be cylinder scavanging IMO.

 

[turbobitt]

I'm just correcting our friend here when he stated that running an appreciable amount of overlap was 'impossible' with a turbocharged engine. People that are reading this stuff don't need to be misled with statements like that.

My statements don't need correcting....

Allan G.

 

[Alky V6]

Don,
You mention that you have over 240 @ .050 lift. I would not consider this high duration and sounds in line with what I have. When I say "high duration", I'm refering to high 250+ @ .050. with tigh lobe seperations in the 104-108 range at these durations. Again, this is all relative info.
Allan G.

I have run 252 @ .050" on a 108 lobe seperation angle, and I was very happy with it. It all depends on how the cam is matched to every other specification of the engine. Every specification. Not just intake manifold volumes.
With that particular engine, I ran 9.10s on 22 psi boost. Destroked, same small heads.
edit: Exhaust was 260 @ .050".

My statements don't need correcting....

Allan G.

You're right. You didn't say it was impossible. You said, 'With a turbo cam, you simply can't have this', referring to overlap.
If you don't need correcting, just how do you explain my experience?

BTW, using the same method for measuring exhaust back pressure, I measured 1.5-1.6:1 when I was running the T76 turbo. Same cam, and the engine was still a monster.

Bison. My BSFC is not out of line for the hp I calculate I'm making. It all has to do with the total combination.

Pulse tunning has its place. I think that ultimate goal and efforts with pulse tunning would be faster spool-up with large turbine turbo's such as your BW 91. The ultimate goal with this pulse tunning is not going to be cylinder scavanging IMO.

Like I already stated, you need to talk to Steve Kinsler of Kinsler Fuel Injection. He even tested a Helmholtz resonator on that Buick V6 I was referring to.

FWIW, the sim I used was Performance Trends EAP.
For me to make the real world results match the sim, I had to pump up the head flow numbers to just about Stage II numbers. You still think pulse tuning doesn't happen on a turbo engine?
My valve sizes are 1.835 int, 1.5 exh.
What are your valve sizes?

This video shows the street characteristics of the cam I am presently using. Very streetable.
DRW / Buick V6 Alky v3.2 20L video test - YouTube

Realize that in the above video I was running a 2400 rpm stall torque converter. It worked perfectly with the T76, but when I switched to the 91mm, which was on the car in this video, the new combination needed more stall speed. I switched to a 3000-3200 rpm stall torque converter, and with the ALS I developed, it's worked out great. The ALS is capable of pushing the stall of the new 3000 stall TC to over 6200 rpm, if I allowed it.

 

[lazaris]

You can talk about pulse tuning, cam specs, dyno numbers all day long, but proof of quality combination, is what the car runs down the race track. A 1.5" header pipe isnt suppose to support 1200 hp.....................on paper..

 

[Dusty Bradford]

250-260@.050. Damn they must have 330' like ass. This one is about 15-20* less duration than that. Dusty how many lb/hr fuel are the 8.50 cars using with a v6 compared to a v8 with the same race weight non oxygenated fuel?

I don't have any logs from a set-up like this. All the V8 cars are 8.0 or faster.

The car was Todd's Stage 2 88mm car. It 330' OK but spool-up to get it on the 2 step was horrible. The cam was at least 8 years old.

 

[Dusty Bradford]

Is it partly due to alot of valve overlap of the older big cams? I would think the high amount of valve overlap would bleed off alot of low RPM cylinder pressure therfore limiting the amount of actual exhaust gasses available to spin up the turbo......making it a dog until the RPMs got on up.

I'm no cam expert so I won't pretend to be. The duration this cam had would probably support 10,000 rpm. The power range was way higher than what we needed when shifting at 7500 rpm. From what I remember every 10 degrees of duration shifts the power band up 500 rpm. It was so low on torque under 3200 rpm it would barely hit 3200 rpm with a very loose converter in it. Once we went with something more modern on the cam it spooled like it was on nitrous.

 

[Dusty Bradford]

Don. What Allan is trying to do is impossible when your not relying on a 300 shot of nitrous to spool.