INTRODUCTION;
After a few years of competitive racing with my HPI RS4 Nitro I found that it was becoming less competitive and starting to wear out to the point that everytime I put it on the track something new(actually something old) broke
Nitro race kits have been getting more and more competitive and I felt it was time to dump the old faithful car for something more in the "top of the line" bracket..
I spent a lot of time, basically all last season, deciding what was, in my opinion, the best high end car on the market..
By the time I went to the 2001 Hobby Show at the International Center in Mississauga, I had pretty much made up my mind..My LHS, Hobby Hobby was there as usual and I found that they gave me the best deal..
One thing I'd like to mention is that even though I finally decided on a Serpent Impulse there are a number of high end kits that could have also gotten the nod..Honourable mentions go out to the Ofna OB4, Mugen MTX and Tamiya TG10R..To name a few.
Serpent Impulse;
The 2000 Radio Control Car Action 'Car Of The Year' is built on a 3mm aluminium CNC machined chassis with a belt driven four wheel drive system...
It has pivot ball suspension on all four independent corners..
The fully adjustable plastic bodied shocks come complete with adjustable threaded shock collars and an externally adjustable piston hole feature that makes fine tuning a snap..
The kit provided yellow wheels and X-Pattern type tires are great for bashing around but when it comes to racing you need to consider slick rubber or foams as the optimum choice.
Unfortunately, not every tire/wheel combo will fit the Serpent Impulse.
For Foam tires we have found that Elleggi 1/10 on-road tires do the trick..(Part #'s EVX4's/EVX5's are some examples)..Other racers are using Pro-Lines with some success, but most non-Serpent tires other than the Elleggi's require some trimming on a Lathe..
Be sure to ask around before you buy.
This kit needs to be built by racers who have some previous knowledge of building R/C Kits.
The manual is awesome looking with its CAD drawings but lacks a bit in the written instruction details.
Some of the screws asked for in certain areas are non-existent and a little investigating is required to correctly install the right parts.The externally adjustable shock pistons are great if you can get them to work..The internals of the shocks are made up of hardened metal piston rods and two part pistons..The pistons thread onto the rod and the threads in the plastic pistons strip very easilly..I made two trips to my LHS to resolve this problem and also many visits to SERPENT.COM.
The Impulse kit uses two brackets to brace the front end of the chassis to the rear end around the engine..The kit provided ones are for a side exhaust engine and only one can be used for a rear exhaust engine..
I thought this would be fine after looking at other Impulses that just left this bracket off and also a lot of other Manufacturer's models that didn't even have brackets on the exhuast side of the car.
However, after running for awhile I noticed that the side belt was rubbing against the Header and since the "after-market" bracket included a belt tensioner that keeps the belt away from the Header(not the belt tensioner's actual purpose of course),I felt it was a necessary investment.
Most of the Team Serpent Racer's use the stock equipment as far as Springs and other tuning parts are concerned..The Foam tires are the only option you need to have to be as competitive as the next guy..Although this kit was somewhat difficult to get assembled, the end result is a very well designed racing machine.
There are really too many differences between this car and my previous HPI ride to list..It is tight and sleek and the tuning abilities are endless..
The Impulse includes a 2 Speed Gear box..Full Ball Bearings..Counter Sunk Chassis..Fully Independant Pivot Ball Suspension..Planetary Differentials..Steel Disc Brake..Nova Mega SX12 Turbo Engine c/w Nova Mega Pipe & Header..
A body isn't included in the kit so I just "slightly" converted my RS4 Nitro Alfa Romeo body to fit..Any after-market 200mm body will fit this chassis..I have a brand new Dodge Stratus body waiting to be painted and mounted but since these bodies take quite a beating at times I'll wait until the Alfa is done-in before installing the new one..Probably mid-season..
All the suspension components are very beefy and look like they could take out a few track barriers before sustaining any damage to the parts.
One negative about these parts is that all the suspension parts on the Serpent Impulse are different..Left is different from right and different from rear or front etc.
If you break a part you have to replace it with the exact part and can't buy a set of upper arms so you'll have a spare..They come in a package of one and are pretty expensive..($10 a part??)
This can get pretty expensive with a car that is capable of reaching speeds of 100 KMH...I've talked to fellow racers who bought Nitro TC3's for example and their A-Arms for instance are the same on every corner of the car..I'd like to see Serpent make this sort of change in their cars..Its ok if you break a part and can zip down to your LHS, but what if you are "at the track" and not able to?..You pretty much have to have spare parts for every part of your car rather than a couple of spares in the case of the TC3.
The supplied Nova Mega SX12 Turbo is one powerful machine..A Co-Team R/C Ontario racer is running the same car with an OS .12 and the power difference is outstanding..I must say though that his car's punch off the line is easier to handle than my Nova Mega so in some cases it may be the better choice..The punch in the SX12 is hard to contain and it can get away from you if you are not careful..Whereas the OS has much smoother acceleration..But power is what Nitro is all about and I like the fact that my Nova Mega has to be held back when fellow racers are having to punch full throttle to keep up..
Running in this motor I did what I always do..I followed the manufacturers instructions to the letter..
1/2 turn out from the factory settings for 4-5 tanks at idle..Then its on to the steet and gradually leaning it out for optimium performance..I'm not even there yet..I do like to run my engines a little rich though and until I notice a lacking in performance at the track I'll probably leave the settings where they are..(approximately back at the factory settings with the bottom end leaned out just a bit more)I could lean it out even more but that could effect the lifespan of my engine..I'd done the same with my OS .12 in the past and got about 7 years out of that powerplant so far.
TIP.......Although not mentioned in the instructions be sure that you use Locktite on all metal to metal surfaces..This includes the engine mounts and also the 'driveshaft adapters' on the Front and Rear diffs..I've had them come off and they are a pain to redo(have to take whole car apart).
Tired of getting glitches at the track with my JR XR2 AM radio and not wanting to get a glitch with my very new/very expensive/very fast Serpent Impulse I decide it was time to switch to FM..I really like my XR2 AM and its features were more than enough for me..So I decided that a good choice for my first FM radio would be the JR XR3 FM radio..I knew my XR2 and what it could do for me and decided that buying the same radio in FM was a win/win situation..
My trusty Hi-Tec HS-605BB servo (dual ball bearings,helical gear,77oz/in. of torque and an operating speed of 0.16 seconds)gets the steering duties and when I bought my new Radio I opted for a single JR 550 rather than the pair of stock JR 250's for the throttle/brake duties....
Final Thought??;
This car is great..Stepping up to this level of competition can be expensive though, so you have to be prepared to pay the price..The Serpent Impulse is not a weekend warrior car and shouldn't be treated as such..If you are willing to invest the time and money necessary to compete at this level the Serpent Impulse is definitely a car worthy of that..With this investment comes commitment to the sport of R/C Racing..I can no longer consider myself a hobbyist and look forward to racing with you and fellow racers at local area clubs..
Don't expect to make this your first car and be competitive..We all have to work our way up to a car like this..(unless we can afford to trash the first one and start again--I can't/couldn't)..Learn within a budget and when you feel you are ready to 'move up', get this car...You won't be sorry..
How Much??;
I'm outta here..No time for 'puters..I got tunin' to do..!!
Reviewed By; THE R/C GUY