Stock and Modified

[Frosty72]

You have to look at the numbers on the graphs on the two sides of the sheet, they are not the same for tq and hp. It's not a great place to do a dyno I guess! Just wanted some baseline numbers. I like the blip on the second one though, now I can say I get 103tq! Ha!

 

[copilot777]

I got my max dynoed today . ( at a Hardley convention and I was very displeased with the guy doing the dyno run.First thing he had a difficult time getting my bike situated on the dyno. and he did the 3 runs and My dyno sheet states that it produced 86.8 ft/lbs tq at 5700 rpm and 125.6 Hp at 9500.()Ok now the catch )To me this almost sounds close to stock numbers for a 1985 or 1986 Max. But My max is supercharged with 12 psi boost and holley 390 carb. Ok now this I know is hurting my performance - stock headers with supertrapp slipons (ran outa money )But do you guys think that stock pipes would hender performance that dramatically Or do you maybe feel the way I do . ( that this guy just ripped me off of 40$) because I was at a hardley show?I would post the sheet but do not have a scanner.Any suggestions would be greatly appreciated . Thanks ,:damn angry:Jason

 

[maleko89]

What was the correction factor?

Stock Vmaxes run 110-115 bhp and about 75-80 ft/lbs of torque.

With that big carb and supercharger I'm sure it would make a big difference with aftermarket headers.

 

[copilot777]

What was the correction factor?

Stock Vmaxes run 110-115 bhp and about 75-80 ft/lbs of torque.

With that big carb and supercharger I'm sure it would make a big difference with aftermarket headers.

Well this guy used no correction factor . and I just felt:bang head: it should have produced well over the numbers he indicated even with the stock headers ? atleast was expecting to see about 135 hp and about 90 ft /lbs tq or so .

 

[QuarterHorse]

Eek!!! I put down 122rwhp with a stage 7, 4-1, and a Kerker!

 

[one2dmax]

many people are dissapointed when they get those setups dyno'd . Sounds about right to me. Change to a full header to really see a good gain.

Sean

 

[KJShover]

I got my max dynoed today . ( at a Hardley convention and I was very displeased with the guy doing the dyno run.First thing he had a difficult time getting my bike situated on the dyno. and he did the 3 runs and My dyno sheet states that it produced 86.8 ft/lbs tq at 5700 rpm and 125.6 Hp at 9500.()Ok now the catch )To me this almost sounds close to stock numbers for a 1985 or 1986 Max. But My max is supercharged with 12 psi boost and holley 390 carb. Ok now this I know is hurting my performance - stock headers with supertrapp slipons (ran outa money )But do you guys think that stock pipes would hender performance that dramatically Or do you maybe feel the way I do . ( that this guy just ripped me off of 40$) because I was at a hardley show?I would post the sheet but do not have a scanner.Any suggestions would be greatly appreciated . Thanks ,:damn angry:Jason

Well, being that an engine is nothing more then a glorified air pump. I'm willing to bet Chris' left nutt that your pipes are choking the efficiency out of your engine. With a system, I'm betting on at least 150hp with 93tq. unk:

theres a video out there of a guy running a similar s/c setup cept he's got a exhaust system and is running a couple more pounds of boost and he's getting over 170hp

 

[4gasem]

Well, being that an engine is nothing more then a glorified air pump. I'm willing to bet Chris' left nutt that your pipes are choking the efficiency out of your engine. With a system, I'm betting on at least 150hp with 93tq. unk:

theres a video out there of a guy running a similar s/c setup cept he's got a exhaust system and is running a couple more pounds of boost and he's getting over 170hp

My right nut's worth more! :whistlin:


Yeah! Air pump! If you're pushing it in you need to push it out!

What was the A/F like?

 

[one2dmax]

Pual Novak has one of those setups with an extremely modified engine and a crap load of boost and still hasn't posted a dyno over 200rwhp yet. He is getting great torque from them.

A stock engined setup usually brings 135 rwhp or so with a good header.

I could get into technical reasons on why this is but it would take a lot of typing. Do a search for adabatic efficiency on superchargers and you'll see the roots type is not very good.

Sean Morley

 

[shawn kloker]

Well this guy used no correction factor . and I just felt:bang head: it should have produced well over the numbers he indicated even with the stock headers ? atleast was expecting to see about 135 hp and about 90 ft /lbs tq or so .

Are you sure about the 12psi boost?Have a gauge?

Normally the Hardly dyno sessions are inflated numbers not low.Scares most of them away making 60 hp.

 

[shawn kloker]

Are you sure about the 12psi boost?Have a gauge?

Normally the Hardly dyno sessions are inflated numbers not low.Scares most of them away only making 60 hp.

Are the cams stock? Degreed?

I would be really pissed off!

 

[Rusty McNeil]

Just as a reference 14.7 psi boost shoulkd double your hp in a perfect world. Hp per psi of boost should be "fairly" linear from 0% at 0 psi boost to 100% at 14.7 psi boost.

Of course parasitic losses and a lot of other stuff derate that number but not on the order of what your talking about.

Something else to keep in mind is that when you lowered the compression ratio with the pistons your baseline isn't 115-120 rwhp anymore, it's whatever the engine would have produced with in normally aspirated fashion with whatever compression ratio pistons you installed.

If your engine became a 100hp engine with the pistons and you put 3-4 psi on it the numbers your quoting sound about right.

If your really making 12 psi boost you should be seeing around 160rwhp or so; assuming the carb can keep up and the exhaust can flow it.

When I installed an ATI procharger running 8psi it took my wifes 350Z from 220rwhp to 343 rwhp running thru an automatic with the stock exhaust and catalytic converters, we never dynoed it after I put the exhaust on it and pulled the cats.. That was with the stock 9.5:1 compression ratio

I believe the regular Magnacharger blower kit is set up for something on the order of 4-5 psi boost.

Are you SURE the kit you bought had the pulleys to produce 12 psi boost? I know you said that it was purchased with the upgraded pistons to handle more boost.....

The first thing I would do is install a boost guage and find out how much boost your really making with your setup. And a free-flowing exhaust will reduce the boost your engine see's due to less backpressure although that doesn't neccesarily correllate with hp output for some reason.

Rusty

 

[113s&s]

i would think bike with boost and without boost ,,,,, running close to same hp numbers,,the boost would pull harder and quicker through the gears

 

[copilot777]

Are you sure about the 12psi boost?Have a gauge?

Normally the Hardly dyno sessions are inflated numbers not low.Scares most of them away making 60 hp.

yeah I have my boost gauge installed and it pushes up to 13 or so lbs boost . but I will say I had supertraps with 15 discs a side maybe choking it way down. so today I removed all the discs and run open ends seems to have more power but still need to buy a full system .:biglaugh:going to have it re dynoed at another location just to ease my mind .and to make sure this guy was accurate.

 

[Rusty McNeil]

yeah I have my boost gauge installed and it pushes up to 13 or so lbs boost . but I will say I had supertraps with 15 discs a side maybe choking it way down. so today I removed all the discs and run open ends seems to have more power but still need to buy a full system .:biglaugh:going to have it re dynoed at another location just to ease my mind .and to make sure this guy was accurate.

What compression ratio pistons did you install?

 

[copilot777]

What compression ratio pistons did you install?

8:6.1:biglaugh:

 

[Rusty McNeil]

8:6.1:biglaugh:

I don't know what to say; while claims for horspower on these things may be inflated, at 12 psi you oughtta be making significantly more than what you are even with the parasitic losses. The heat matters too, and it 12psi and no intercooler you're making plenty of heat, but to my knowledge heat will only effect reliabilty by driving you into detonation if timing and A/F ratio are not managed properly; but shouldn't drive down HP that much.

Have you gotten an A/F graph on it?
It'd be worth your while.

At more than a couple of psi of boost you should be somewhere around 10.8:1-11.5:1 A/F ratio, any leaner than that and you're flirting with detonation.

BTW,

I'm still jealous and STILL want one of these.

Rusty

 

[QuarterHorse]

In all the boosted auto apps I've had you don't want any fatter than 11.0 A/F ratio. You'd be washing down cylinders and ruining engines. I would say the window should be between 11.5 to 12.5, but this is all in boosted V8. I wouldn't think a V4 should be any different.

N/A A/F ratios would be between 12.5 and 13.2ish. 13.5 is lean in my book.

 

[Rusty McNeil]

In all the boosted auto apps I've had you don't want any fatter than 11.0 A/F ratio. You'd be washing down cylinders and ruining engines. I would say the window should be between 11.5 to 12.5, but this is all in boosted V8. I wouldn't think a V4 should be any different.

N/A A/F ratios would be between 12.5 and 13.2ish. 13.5 is lean in my book.

I believe on second thought that you are correct sir!

Richer than 11.0 is probably too rich and could cause ring wash.

I wouldn't be comfortable with 12.5:1 in boost over more than 3 or 4 psi tho'; unless something that monitors knock and pulls timing accordingly was in service.

On my wifes car we used a J&S ultrasafeguard to do that job. It's a fantastic little device.

Rusty

 

[QuarterHorse]

I believe on second thought that you are correct sir!

Richer than 11.0 is probably too rich and could cause ring wash.

I wouldn't be comfortable with 12.5:1 in boost over more than 3 or 4 psi tho'; unless something that monitors knock and pulls timing accordingly was in service.

On my wifes car we used a J&S ultrasafeguard to do that job. It's a fantastic little device.

Rusty

Sine I'm unfamiliar with boosting this small an engine, I would be ignorant about what boost numbers to start monitoring, but I would have figured around the 6lb area, but your probably right.