Topic: Thinking about getting bigger cam??

[Gnarly4X]

Gnarly,

Do any of your computer dyno runs show the 'dip' I usually see in the dyno run I usually see around 3k +- rpm for various vehicles?

This is for my Sportster (883):    first is dyno at dealer, second is something called a 'road dyno' (search images 'road dyno software')






I've used the 'road dyno' on my 86 22RE truck and 64 Plymouth Valiant slant 6 225, and they both showed the 'dip' (don't know where I put the .jpg of those) that DON'T show up on a computer simulation (Desktop Dyno 2000 & 2003)

That is a good question.  Let me do some checking and see.  I've seen "dips" in dyno curves.  I believe it is not unusual and is almost always a question (What's the dip and why is it there?) when tuning on a dyno.  My software simulates an engine dyno (still possible to show a dip), so a chassis dyno may read several factors that can cause peaks and dips in a curve.

I'll get back to you on that and I can post some curves from my software.

Gnarls.

[Gnarly4X]

I'll come back and read everything later but some highlights from my memory

stock 20 R carb is 190 cfm
stock 22R carb is 325 cfm  which makes the 3236 weber a perfect replacement but the stock carb out performs the weber for offroading in tuned correctly

20R combustion chamber 75cc early and 81cc ish in 79 and 80 and up.
22R  is about 85cc also
22re 55cc
22RET is also 55cc  (pistons are different)
stock 20 and 22R cams was around 390 and about 190 duration it started off about the same ramp as the 215* but since emissions sucked the close side drops off sharply

My setup has one thing I really love about it.  when pulling a heavy load once  my soninlaw and daughter were following me and she called me on the cb and said "Dad, do you know that when you shift a 3 or 4 foot flame shoots out the exhaust?" 

Hey 79coyotefrg.... where have you been hiding?? 

Gnarls.

[79coyotefrg]

Hey 79coyotefrg.... where have you been hiding?? 

Gnarls.

been having bad migraine headaches and the medicine screws with my memory

[Gnarly4X]

been having bad migraine headaches and the medicine screws with my memory

Well... crapity!..... I was hoping for an interesting reason that you've been absent from your post participation.

I'm familiar with pain and medication that screw with my memory!.... and it sucks!

I miss your posts buddy!

I'm wishing you all the best with getting well and getting back to your normal self.

Gnarls.

[:)bestgen4runner]

Gnarly, are you still planning to have your truck run on a dyno?
I have only known one guy to do it with a 22re. It was a 2.7L stroker build by engine builder.
The results.... well...... very disappointing.
I believe it was 102 hp, So sad!
He made a few changes and had a second set of dyno runs performed. the result.... well........ more disappointing. 100hp on the dot.
Oh and the but dyno, I rode in it three times and drove it once....
Well....... Yep.........
You guessed it very disappointing.
I rode in Andrew's 4runner with the 3rz once. Well....... It would have destroyed that 2.7L stroker 22re, no question.

[H8PVMNT]

I have a friend of a friend over in Missoula who recently had something like 50 HP at the wheels with a stock 22RE with a typically built 4Runner, so 102 HP may be pretty good in reality.

I liked the 3RZ, but I did not personally think an additional 40-50 horse was worth the trouble of the swap.  Don't get me wrong it was that "just enough more" that you wish your 22re had.  Perfect trail rig engine for sure.  It's just that the exact same amount of labor could get you a lot more power.

Next time I do a real swap I want to do a 1UZ or maybe a 2UZ in something.  Like a mild looking pickup with skinny 33s on it .

I think, after having a 3RZ, several 22re, 20r, and the 22r that the 22re EFI is the limiting factor, both the best and worst thing about the 22re.  I can net large perceivable, seat of the pants changes with carb with a small amount of effort, where you can throw all kinds of stuff on a 22RE and you won't see much after freeing up the exhaust and having a good tune up.  I did a cam, intakes, AFM messed with.  The header helped, proper gearing was huge, not much else did anything.

I know this rambling is kind of off the topic of the cam thread, but I think the relevance is that what I found over the years was the 22RE is probably happiest in a near stock state of setup.

[andykrow]

you won't see much after freeing up the exhaust and having a good tune up.  I did a cam, intakes, AFM messed with.  The header helped, proper gearing was huge, not much else did anything.

I have to agree here for the most part. Gearing and exhaust. Jury is still out on my current build with the Street RV and 261 - I'm anxious to see how it does on the third climbs on 170 at 11k feet.

I believe it was 102 hp, So sad!

If this is 102 at the wheels that is not really that sad, is it? These are stock 116 at the crank. I'd guess more like 60 at the wheels stock. What was engnbldr hoping to see?

Well, I guess 102 is sad considering how much money that probably cost. And I would assume reliability is out the window.

[emsvitil]

The rule of thumb is 15% loss....

So 102 / .85 = 120hp.........

[kneedownnate]

Several years ago I sold a stock 82 2wd truck to another board member pretty cheap.  He tinkered with it while going to wyotech, added a weber 32/36, tuned it as best he could and ran it on the dyno and got 95 hp and 130 ft lb of torque.  Sad that a stroker, which should have much more potential, go so much less.  I can't remember if he ever changed the cam, but I don't think so.

[andykrow]

The rule of thumb is 15% loss....

So 102 / .85 = 120hp.........

Wow. Yeah, sad indeed.

[Gnarly4X]

Gnarly, are you still planning to have your truck run on a dyno?
I have only known one guy to do it with a 22re. It was a 2.7L stroker build by engine builder.
The results.... well...... very disappointing.
I believe it was 102 hp, So sad!
He made a few changes and had a second set of dyno runs performed. the result.... well........ more disappointing. 100hp on the dot.
Oh and the but dyno, I rode in it three times and drove it once....
Well....... Yep.........
You guessed it very disappointing.
I rode in Andrew's 4runner with the 3rz once. Well....... It would have destroyed that 2.7L stroker 22re, no question.

Yes... I want to do some chassis dyno testing on my truck.  I hope to get this engine running like I think it should, with a good number miles and then get it on the dyno at a local Phoenix speed shop.

I realize that the chassis dyno will produce some lower power numbers than a SuperFlo 902.  The numbers will also be lower than my DD software, which virtually simulates an engine dyno calculating brake HP at  the flywheel.

I don't think I'll be disappointed... nor do I think I'll be surprised.  BUT... what it will do for me is start with a benchmark.  Then... whatever I do to my engine (or gearing) from there, I can compare the changes on the dyno.  I realize there are some significant variables and the numbers can be accurate, close, off, or difficult to analyze the actual cause and effect.

I look at my research and testing as more fun than an overly serious attempt at gaining some profound new revelations about these little engines.

Regarding the stroker.  I mentioned before that I drove a 22R stroker in an early pickup, built by an engine builder who builds Toy engines for racing.  I was surprised, disappointed, at its lack of throttle response and I didn't feel it had very much more power over my stock 85 22R in my shortbed with just a DT header and 2.25" exhaust,  and my Double Gnarly
Air Filter Mod.

I am already looking at building another engine.... an aluminum block V-8... and swapping it for my 22RE.

Gnarls.

[Gnarly4X]

I have a friend of a friend over in Missoula who recently had something like 50 HP at the wheels with a stock 22RE with a typically built 4Runner, so 102 HP may be pretty good in reality.

I liked the 3RZ, but I did not personally think an additional 40-50 horse was worth the trouble of the swap.  Don't get me wrong it was that "just enough more" that you wish your 22re had.  Perfect trail rig engine for sure.  It's just that the exact same amount of labor could get you a lot more power.

Next time I do a real swap I want to do a 1UZ or maybe a 2UZ in something.  Like a mild looking pickup with skinny 33s on it .

I think, after having a 3RZ, several 22re, 20r, and the 22r that the 22re EFI is the limiting factor, both the best and worst thing about the 22re.  I can net large perceivable, seat of the pants changes with carb with a small amount of effort, where you can throw all kinds of stuff on a 22RE and you won't see much after freeing up the exhaust and having a good tune up.  I did a cam, intakes, AFM messed with.  The header helped, proper gearing was huge, not much else did anything.

I know this rambling is kind of off the topic of the cam thread, but I think the relevance is that what I found over the years was the 22RE is probably happiest in a near stock state of setup.

I agree.

Gnarls.

[Gnarly4X]

Gnarly,

Do any of your computer dyno runs show the 'dip' I usually see in the dyno run I usually see around 3k +- rpm for various vehicles?

Here's a graph from the CompCam252S in my engine.  I see a small "dip".  Is that the type of dip you are referring to?

Gnarls.

[Gnarly4X]

Here's another graph with a more obvious dip.

It's a 1970 Chevy Z28 350ci.

Gnarls.

[emsvitil]

The second one looks like what happens in the real world........

With desktop dyno,    the second one wouldn't  have a dip, and the TQ curve would probably peak at 415 @ 3200 rpm....

[Gnarly4X]

Hey emsvitil,

I'm not sure what you’re thinking or what the point of your question was?

You probably already know….

Many dyno torque/HP curve charts have dips and peaks, whether tested on a chassis dyno, engine dyno, or a software dyno program.

Where in the RPM range a dip occurs can vary depending on a number of factors.

Engine Analyzer simulates so by definition it could be considered not real world… it’s theoretical, but highly repeatable.

An engine tested on a SuperFlo 902 is real world, with some simulated data included… highly controlled environment and only slightly theoretical (mathematical formulas are applied)

An engine tested in vehicle on a chassis dyno is real world, with some simulated data included, with added physical components…. perhaps considered more real world, still somewhat theoretical (mathematical formulas are applied)

A 4th paradigm is when the vehicle is tested on a road course, track, or actual conditions (i.e. drag strip) by the driver.  Actual results of target changes, tuning or component changes, may or may not parallel what was predicted in the Engine Analyzer software, shown on the charts and data from the SuperFlo dyno, or the DynoJet chassis dyno test results.

The driver’s butt-dyno provides “real world feedback” and track times can prove or disprove all previously theoretical, predicted, or data test results.

Gnarls.

[emsvitil]

My thinking was that you seemed to be highly reliant on the software for your cam selection, and in the rpm range you were interested in I've always seen dips in the torque curve on 'real' tests.

If the software you were using didn't show dips (desktop dyno doesn't seem to be good enough to show dips) you could easily pick the wrong cam.

[H8PVMNT]

That is called the "bean dip".

[emsvitil]

I thought bean dip gave you rocket propulsion...........

[Gnarly4X]

My thinking was that you seemed to be highly reliant on the software for your cam selection, and in the rpm range you were interested in I've always seen dips in the torque curve on 'real' tests.

If the software you were using didn't show dips (desktop dyno doesn't seem to be good enough to show dips) you could easily pick the wrong cam.

Hi emsvitil,

I'm not highly reliant on the DD data.  It looks optimistic.  The gains that it shows are disputed by at least one 22RE engine builder.  I just have owner feedback - which obviously varies, and the published claims.  But in the absence of any "real world" test data, I'm just looking at what is predicted in the "changes" to cam profiles.  I fully understand it may NOT be accurate.  I will not be surprised if an actual dyno test shows dips in the curve.  I "feel" some dip in the pull when I tach my engine to 5,000 RPM.

Gnarls.

[Gnarly4X]

I thought bean dip gave you rocket propulsion...........

Bean dip almost always provides me more propulsion.... I'm not sure what octane I'm burning, but it usually produces a nice exhaust tone!

Gnarls.

[Plainview]

Since this discussion is ranging all over the place...

I've never understood how parasitic loss through the drivetrain could be a percentage.  That would mean a really powerful engine would lose more power than a less powerful engine turning the same components at the same RPM.

A transmission should take a given amount of power to spin it at a given RPM.  The internal friction would not change based on the engine in front of it.  Same with differential and all the other sources of losses such as the axle bearings, u-joint bearings, tire rolling resistance, etc.

So let's say we have an engine that puts down 150 HP at 5000 RPM on an engine dyno.  Put it in the vehicle and you're seeing 100 HP at the wheels - you have 50 HP of loss in your drivetrain at 5000 RPM.  If you put an engine that is making 400 HP at the crank at 5000 RPM in the same car you should see 350 at the wheels.

Can someone explain how that line of reasoning is wrong?

[H8PVMNT]

Seems like sound reasoning to me.

[andykrow]

This is kind of interesting: http://www.superstreetonline.com/how-to/engine/modp-1005-drivetrain-power-loss/

TL;DR: The 15% "rule" does not hold true at all and varies widely. A more powerful engine will experience a higher HP loss on a specific drivetrain due higher acceleration (dynamic drivetrain loss.)

I would guess our little 22RE platforms lose way more than 15%. Our drivetrains are built (over-built) for reliability, not efficiency.

[Gnarly4X]

Since this discussion is ranging all over the place...

I've never understood how parasitic loss through the drivetrain could be a percentage.  That would mean a really powerful engine would lose more power than a less powerful engine turning the same components at the same RPM.

A transmission should take a given amount of power to spin it at a given RPM.  The internal friction would not change based on the engine in front of it.  Same with differential and all the other sources of losses such as the axle bearings, u-joint bearings, tire rolling resistance, etc.

So let's say we have an engine that puts down 150 HP at 5000 RPM on an engine dyno.  Put it in the vehicle and you're seeing 100 HP at the wheels - you have 50 HP of loss in your drivetrain at 5000 RPM.  If you put an engine that is making 400 HP at the crank at 5000 RPM in the same car you should see 350 at the wheels.

Can someone explain how that line of reasoning is wrong?

There's some good technical discussions on chassis dyno vs engine dyno calculations on the internet and published in books.

But.. to simplify it.... there is a "general average" percentage of loss thrown around that is probably fairly accurate in most chassis dyno tests being done on known vehicle engine specs and the vehicle chassis they are mounted in.

Keep in mind that most dyno testing, chassis or engine, is for tuning and seeing power gains based on typical modifications or component changes.  So, a base or bench mark test is typically done, then the mods done, then another set of pulls to calculate changes.

That is probably not the comment you are looking for, but if you really want to know more, do some research and I think you will find some really interesting insight into dynos, variables, and results.

Gnarls.

[Plainview]

This is kind of interesting: http://www.superstreetonline.com/how-to/engine/modp-1005-drivetrain-power-loss/

TL;DR: The 15% "rule" does not hold true at all and varies widely. A more powerful engine will experience a higher HP loss on a specific drivetrain due higher acceleration (dynamic drivetrain loss.)

I would guess our little 22RE platforms lose way more than 15%. Our drivetrains are built (over-built) for reliability, not efficiency.

That link triggers my malware/virus software.  Looks like it tries to download something onto your computer when you open the page...?

[andykrow]

That link triggers my malware/virus software.  Looks like it tries to download something onto your computer when you open the page...?

Ugh, that's weird. Found it through google which usually weeds stuff like that out??

[Gnarly4X]

That link triggers my malware/virus software.  Looks like it tries to download something onto your computer when you open the page...?

 

Gnarls.

[Gnarly4X]

..........google which usually weeds stuff like that out??

Really?........ are you on a Valium drip? 

With 3.5 BILLION internet users and 40,000 search every second ... it's impossible to "weed stuff like that out".

There is a million+ new malware threats released every day.

andykrow... I have clicked on that site before and again since you posted the link.  The only thing it triggered is a momemtary pause to refill my glass of Black Cherry Kool-aid.... 

Gnarls.

[Gnarly4X]

...  If the software you were using didn't show dips (desktop dyno doesn't seem to be good enough to show dips) you could easily pick the wrong cam.

Hi emsvitil,

The software does in fact "'show dips"... and there are probably thousands of curve graphs produced by the Engine Analyzer program that show that.

There are many engine dyno curve graphs that do not show a dip in the torque numbers through any given RPM range.

As far as picking the right camshaft, so far reading the posts from several forum members here, picking the wrong camshaft can happen regardless of information or research.  After picking a camshaft, even if it "feels" like the right one, how would you know unless you test for a comparison?

The software is just a tool to help in performance tuning, like changing jets in Holley carburetor.

If you are curious about the program's practical use as a tool.... read this:

http://performancetrends.com/what_our_users_say.htm

What do YOU rely on when you pick a camshaft?

Gnarls.