F.A.S.T. Racing 4 mil Serval Cub

[06specialedition]

Just got back from the dyno, all I can say is EPIC dyno session.

 

Numbers?

[Trick2stroke]

Awesome, excited to see the results.

 

He posting in here or making a new thread in the Dyno section?

[Fastassbanshee96]

I can't wait to see these sheets. Post them up.

[05stroker]

Now remember this dyno is going to read lower as it has the eddy current brake on it. That being said we tested the pro circuits with 296 forest silencers and 304 factory sound silencers (the outcome may shock you). We also tested the CPI's and Trinity's. We wanted to test these all on the same dyno so there would be no confusion or trying to compare numbers from different dyno's. This dyno is known the be very conservative. Here is the chart with the 4 setups that are listed above. We also tried some different curves on the dyna ignition and got the jetting sqaured away. I understand the Pro Circuits may not pull to the moon, but I know for a fact that is not where I want my power. I'm not constantly running it at the redline. It's not a drag bike.

 

(Light Blue) Run 19 Pro Circuits 296 (Forest Approved!!)

(Red) Run 23 Pro Circuits 304 (Factory Sound)

(Green) Run 26 CPI

(Dark Blue) Run 28 Trinity Stage IV

 

Just to clarify THE PRO CIRCUITS WITH 296 SILENCERS ARE THE LINES ON THE TOP OF THE GRAPH!!!!!

 

HP and Torque for all four setups.

 

 

Same curves without torque and the writing out of the way.

 

 

Pro Circuits by them selves

 

 

 

I will get a picture up of the timing curves and give you guys all of the jetting and setup specifics in a few minutes. While I'm doing that go order some Pro Circuits for your Serval

[Judge1]

Is it just me or is this about 10 hp short of what has been advertised? Is the small carb holding this back?

[Snopczynski]

This better. (unloaded run)

 

You guys need to understand this was a very reputable dyno, from a very reputable company. It has an eddy current brake on it that loads the dyno down to a simulated real world load vs an inertia dyno which applies one laod the same way all the time. You also cant compare two dynos because no two ever read the same. You need to be looking at the differences between all the pipes ran on the same dyno, the same day, on the same bike. Thats were the answers are here.

 

All 3 of these runs were with Pro Circuit pipes and 296 silencers.

[06specialedition]

wow, so the pc's make more hp on the serval than the cpi's.

 

X2 with judge, wonder how some bigger carbs would do?

[Snopczynski]

According to Dave at Rooster, he felt the bigger carbs would add hp up top, but take away hp and acceleration speed down low. That is not what 05 stroker wants on his motor, thats why we have 28mm carbs on it. The dyno tuner felt you gain about 1 hp on the top with a transition in the mid per every mm with the sizing up of the carbs.

Dyno Sheets

[05stroker]

Here's the setup

 

4mil Serval with cleanup

22 cc domes with .054 squish

156 psi 92 octane pump fuel

stock reed cages/intakes with boysen power reeds

TM 28mm Mikuni's

p4 175 nozzle

air screw 1.5 turns

Pilot- 25

Needle 5L1 1st clip

Main- 460

Pod filters

Pro Circuits with 296 silencers

BR8ES plugs at .024

 

Here's the timing curve we had the best results with. It's basically curve 3 modded a little. If you have a timing plate I wouls say put it at +4 and call it good.

 

Edited March 21, 2011 by Snopczynski

[gizmoman]

A little lower than i expected but still nice, really wish i could find a local dyno to compare the different settups.

[Snopczynski]

You cant compare anyone else's numbers to this dyno because it is not the same dyno. This isn't even the same type of dyno the other builders have posted graphs from. You have to like at a pipe to pipe or part to part comparison on the charts. Not dyno to dyno numbers.

[camatv]

wow hard to understand why silencers with spark aresters made THAT much more power over the whole gap sparkys are known to choke the hell out of pipes..

 

hmmm??

 

i have NEVER had ANY bike with CPI's seem to make MORE hp with pro's.. dont get me wrong i like pro circuits but again thats a 421 serval?? on pump gas making similar HP as PORTED STOCK 350CC motors??? EVEN on pump gas!!!!

 

 

maybe i'm not seeing something there i should???

 

my 421 stock cylinder on 110oct made a steady 80hp and 55ft lbs of tq. and it was ran on a so called stingy dyno and was an eddy current style with adjust able loads.. even under a hard load it still squeaked out 69hp. that was a STOCK cyl motor.

[Snopczynski]

HOLY SHIT, IT IS A DYNO WITH AN EDDY CURRENT BRAKE, THE RUNS ARE LOADED. IT WAS NOT A DRUM INERTIA DYNO. THE UNLOADED RUN WITH JUST THE DRUM INERTIA PUT OUT 79.86HP! MY bike as a ported 350 dynos at 66.76 hp on a crank dyno with a dynomite water brake, my specualtion as to what it would put down on this dyno is about 58-59hp.

 

Pay attention to the number comparisons on the runs, not the dyno numbers compared to other builders numbers. They are not similar to other dyno graphs we have seen from other builders because it is not the same type of dyno. I have ridden the bike we dyno'ed today and it has A LOT MORE power than my 350 has.

[WINDYCITYJOHN400]

HOLY SHIT, IT IS A DYNO WITH AN EDDY CURRENT BRAKE, THE RUNS ARE LOADED. IT WAS NOT A DRUM INERTIA DYNO. THE UNLOADED RUN WITH JUST THE DRUM INERTIA PUT OUT 79.86HP! MY bike as a ported 350 dynos at 66.76 hp on a crank dyno with a dynomite water brake, my specualtion as to what it would put down on this dyno is about 58-59hp.

 

Pay ettention to the number comparisons on the runs, not the dyno numbers compared to other builders numbers. They are not similar to other dyno graphs we have seen from other builders because it is not the sme type of dyno.

 

 

Relax. For starters you showing everyone oranges when they are use to seeing apples. Second, your doing what you have a history of doing... putting 28's on litteraly every motor I've ever seen you comment on. You tell people to pull thier 2 into 1 intakes and get 28's for their 350's now you think 28's are best for a 421? I'm not saying jump to a 35PWK...but why not try a 30 or a 33 or 34? All you have shown is when a motor only has 28's to breath through , it likes the Pro circits. (another thing you have a rep for is thinking the PC pipes are best on everything) If M+M and everyone selling these motors claims they make 80HP and 50 ft lb of torque stock....why don't you post dyno runs WITHOUT the eddy current readings so people can compare apples to apples. Your doing 2 things MOST people who are waiting to see independent dyno resluts would never do.....your starting with 28's and PC's. I understand the point of your build goals. But by posting them with the eddy current runs, your only making your info look like it is in another language. How in the world are the same pipes and carbs that work best an a 4mill ported stock sylinder with @ 385 cc's, the best chioce for a 421cc motor. Shit the whole world says to the 421 cub owners to ditch the 35's and get 39's. Is there ever going to be a build that you would run a 35 carb on? Ditch the SB CPI's and try a set of SB Shearers. They made 14 more HP on my motor and all the same low end power of my CPI's. Show us some different carb choices next, because 28's aren't the "Do all, Be all" carb. If 2 - 28's can feed a 421 ...why can't a single 35 feed a mostly stock 350?

 

I know it sounds like a rant...but I understand the dyno issues (We have a DynoJet 188) and even I find the results to be a little misleading.

What are your A/F readings? A pipe can look good vs. another pipe if the A/F readings are lean. The smaller pipe might favor the lean condition.

Dynojet dyno's AREN'T different from one to the next. (using the eddy current brake will show different results from a non eddy current run) but in the inertia mode it will read the same as mine. (That's why the DynoJet is the industry standard)

I was expecting to see improved results from the previous posted advertized results. All you have shown is that your motor (which thanks to your eddy current run style looks low anyway) seems to like the PC's. Nowhere is there anything that says the carbs are even close to the right size. (You didn't try a bigger carb?)

The eddy current mode is used for diaing in your jetting at different RPM stages. Final dyno numbers are more often done without the eddy current in use. (80% of chassis dyno's don't have the eddy current feature) So why not just list runs that compare with others, so we can compare results. (Yes I know runs made in one area of the country under different weather conditions will very the results) But they will be ALOT closer than the eddy current results and cause less confusion.

[Snopczynski]

I did post an unloaded run. It was 79.86 hp. It is a few replies up. You even qouted the hp reading from it in your post where I had the GIANT text.

 

As far as carb numbers. We have a two 443cc 7mm cub motors that were re-sleeved and ported to specs similar to a serval. One ran one with twin 28mm mikuni tm's bored to 30mm and pro circuits on it. That motor put down 94hp on the crank dyno with the dynomite water brake. The other motor which was identical to the first in every way except pipe and carbs was ran next on the same dyno. We ran it with a single 38mm lectron and pt mids, it put down 87hp. We switched it over to pro circuits and it put down 92hp. Same dyno, same motor setups. Better results with the small twins over the 38mm lectron single.

 

No one tests smaller carb setups, just like no one tests pro circuits, pt mids, or fmf gnarleys. So how do you know what a 421 needs. Especially one built to make low-mid power instead of being drag ported. Everyone said normal rules don't apply to this cylinder, we just proved they do apply. Low-mid cylinder with low-mid parts equals good results vs the mid-top parts which did not work as well. So tell me how you know what a 421 Serval needs if no one has ever tested these parts on them?

 

I have a ported 350 that put out 66.76 hp on the crank dyno, and I have ridden this serval bike. It has a LOT more hp than my ported 350 does.

 

The guy who ran these tests rubs elbows with guys like cameron at Redline Racing. He built a banshee called the sandbomber, and he is very active and competitve in drag racing on the Oregon coast. He knows what he is doing, and he tolds us going into this that the numbers were going to be lower than an inertia dyno because of the eddy current brake. He said these are strong numbers for his dyno, and he would run the same setup for what we were trying to do. That is not win drag races, but make a dune bike with usable power. This motor has 1,750 rpm of torque backup on it. That make us able to climb up a tree ridden hole, let of the throttle to dodge a tree and re-apply throtle and come right back up on the pipe.