First and foremost; I am not a qualified mechanic nor do I have any formal automotive training, in fact I don’t even hold a degree. (gasp!) This however does not mean I am unskilled and most certainly not inexperienced. Further, I hold no affiliation with Kenne Bell other than I have purchased and installed one of their supercharger kits, for my own personal use.
While I can attempt to outline my experiences with this supercharger, and answer specific questions pertaining to how I did things, I cannot answer technical questions about the Supercharger itself. Those specific questions are best suited to the qualified staff at www.kennebell.net
For anyone who has not read the install, it can be found posted on a variety of online forums, one such copy is listed here:
To completely sum up the entire document for the impatient I’ll begin with the end:
Conclusion:
After the first season of use, I am quite happy with my purchase. I have experienced no mechanical failures, performance shortfalls, or problems. I have noticed and remarked about Kenne Bell’s rapidly improving customer support, and communication. I would purchase this product again without hesitation.
Thanks for reading,
Darren (5.0L) Lynch
Onwards to the meat and potatoes of the document.
The foundation of this install is well accounted for in the install thread, but for the basics here it is:
1995 Mustang GTS 5.0L - 5 Speed – 3.55 Gears
Factory short block had 182,000km’s (114,000 miles approx) when the supercharger was installed.
Trickflow TFS heads - Factory camshaft – 1.6 Scorpion Rockers
Long-tube Headers – Off-road Midpipe – SVO Side Exit Exhaust
Ported GT40 Intake Manifold – 75mm Throttle Body – 90mm Lightning MAF – Custom fender well Cold Air Intake Tract.
42lb/hr Ford Racing Injectors – Walbro 255 L/Hr Fuel Pump - Factory Fuel Pressure Regulator and Rail.
Professionally Tuned using a TwEECer R/T – Mallory Hy-Fire 6A Ignition – Crane Fireball 2 Coil – 1 Step Colder plugs 0.035” gap.
Kenne Bell 2.2L “Blowzilla” Twin-screw Supercharger, GT40 Lower Intake manifold, 90mm Flowzilla Inlet, Integral bypass. Pullies for 6, 10, 14, and 18 lbs of boost.
That should about cover it for parts pertaining to the engine side of things.
The overall intent of the project was to end up a balanced car, that could give a decent account of itself on a road course, drag strip, and hooliganize the street where it would serve most of its duties. In the end, I believe this was completed to my satisfaction, but with any modification there are things that I wish to further hone.
Care and Feeding:
Fairly basic here, always ensure the supercharger (henceforth also referred to as the blower, and other slang) oil is within the specified levels, changed as directed and good quality fuel is used. Aside from that it’s pretty like any other moving part on an engine, inspect obvious problems should they occur.
As is important with any performance vehicle, good fuel is a must, and my car became very sensitive to “bad” fuel. During my first major road test with the supercharger, I found myself in a little town called Creston, British Colombia. While I had no problem finding good fuel on my trip in, it became necessary to fuel up to begin my trip home. (1,000 miles round trip) There were only a handful of stations there, so I picked the Esso with a cluster of sport bikes fueling from the premium pump. (91 octane) Within few miles from the station I had knocking and pinging at the first touch of boost, certainly alarming. One feature I had programmed into the TwEECer was a few different WOT spark tables, for adjustments on the fly. I had 17, 15 and 13 (limp home) degree tables for different situations. Usually I could run the 17 degree tune at 11 psi without issue, sometimes if it was hot out I would need to use the 15 degree map, never had I needed the 13 degree one until now.
So for the next 200km I climbed a mountain range and stayed out of boost doing so, (more on that bypass valve later) not the fun romp one usually has in hilly country.
My next stop was at a Chevron gas station, 94 octane and a bottle of octane boost later; I was breathing a sigh of relief as the car was able to run 17 degrees again.
I almost wonder if the Esso station had 87 octane filled in the premium tank, and I also wonder how the guys on the sport bikes got on…
Lessons Learned (Fuel):
1. Always use the best fuel available, from a high volume station.
2. It may be handy to keep a bottle of reputable octane boost in the trunk. (KB recommends NOS Race Formula)
3. Being able to adapt your timing tables on the fly might also be a good capability to have.
4. Having a Vacuum/Boost gauge can help you anticipate and avoid part throttle boost when having problems with poor fuel.
5. The bypass system for the Flowzilla is certainly worth the purchase when experiencing these problems.
Cooling;
Something I also observed on that trip related to cooling of the engine. Until that trip, the car had been equipped with a March under drive pulley set, which as you may know “frees up” existing horsepower by turning accessories like the water pump at a slower speed. I had not experienced any major problems with this arrangement until I unluckily found myself wedged in bumper-to-bumper traffic anchored to Calgary’s Deerfoot trail. During this 45 minute torture test, the temperature began to creep steadily toward the ‘H” side of the gauge, while Ford factory gauges are not very accurate, the air temp from the heater confirmed my fears. In the end I was able to push through the gridlock without overheating and owe the “heater core as a second radiator” trick and my electric fan for the success.
In preparation for my next big trip I re-installed the factory pulley kit and coolant temps were completely manageable from then on.
Another footnote is that I have been using a 180 degree thermostat, which is significant because Kenne Bell supplies and insists on a 160 degree unit. My choice to use a 180 degree T-stat came after careful consideration and discussion with local racers and tuners. Based on my location, (Edmonton, Alberta Canada) which is somewhat more northern than California where Kenne Bell is located, experience has found that since our summers rarely see daytime high of greater than 95*F a 160 thermostat usually causes problems with open/closed loop switching. While I do not advocate using a 180 degree thermostat for all users, it may be a solution if you have problems. Should cooling have continued to be an issue, the 160 T-stat was ready on the shelf.
Lessons Learned (Cooling)
1. Monitoring cooling problems is best done with an accurate gauge; a reputable aftermarket unit from your preferred company should do the trick.
2. Underdrive pulleys are probably not a great idea as they reduce water pump speed at idle, where you need the circulation most This may be mitigated with the use of the Kenne Bell supplied 160 degree thermostat.
Further about the March pulley kit and boost levels, I had been running a crank to pulley ratio which should have generated 10 psi, but I had been seeing 11 psi on the gauge. I suspect that March’s crank pulley is a little smaller than Kenne Bell’s literature assesses, and may over-spin the blower somewhat more than you plan. For me this condition went away once I switched back to the stock lower pulley and ordered a matching 10 psi upper pulley.
3. In a pinch, turning the heater to full-on and fan speed to high, you can get a marginal cooling increase at cost to passenger discomfort. Remember, passengers are replaceable but engine tear-downs are time consuming.
The Big Trip;
After logging over 1000 miles on the combo, I decided it was reliable enough for a more ambitious long distance run. The plan was to attend a large muscle car show in Lethbridge, Alberta and from there run to Las Vegas and return. I figured why not use the GTS? This 4800 km round trip would certainly be an interesting go, provided everything went as planned. In short, it did.
I departed from Lethbridge after the Sunday car show had finished up, and found myself in Helena Montana about 5 hours later. Driving at the Interstate mandated 75 MPH really made the miles pass quickly, but considering I sat in the sun during the car show, I shut things down for the evening at 9 pm.
The next leg of the journey went across 5 states from Helena MT to Las Vegas NV in 10 hours of near constant driving. A little observation about the trip down was summed up in a forum post I had made upon my arrival:
Quote:
Originally Posted by Darren5.0L; How about those inefficient parasitic Superchargers? So far this entire trip I have averaged a terrible 26.5 US MPG, spending much of my journey a rather high elevation, 7500ft at one point, and 5000-6500 was rather common. My worst MPG was 18.5 climbing some mountain in Montana, and beating on it through the twistys down the other side. However I did see 29.3 from Pocatella Idaho to Salt Lake City Utah. I just don't know what to do about this thing, my 1960's engine equipped with a inefficient power adder still hasn't burned a drop of oil, despite having over 185,000km's. |
Boost Bypass
In the old days of Positive Displacement superchargers, the car was always in boost anytime the engine was running. This additional airflow requires appropriate amounts of fuel to run at a safe A/F ratio, compression heated the air charge, and it drew power from the engine.
Simple enough, but as technology progressed, the use of a simple vacuum actuated valve allows a car to run with almost a dual nature. Kind of like Mad Max’s Interceptor, without a complicated clutch type supercharger pulley.
Essentially in high vacuum conditions like idle and cruise, the bypass stays open. Even though the supercharger is spinning, it is nearly freewheeling, drawing less than 1/3 of a horsepower, generating nearly no additional heat, and requires really no extra fuel. The engine is just as fuel efficient as it would be without the blower.
On the demand of your right foot, (WOT, 0 inches Vacuum, or heavy load) the bypass snaps shut and since the supercharger is already spinning at speed, it generates full boost instantly. With very little practice it is very easy to decide with your right foot whether you want to be in boost or not. Of course once in boost all expected supercharger physics apply normally.
Once arriving in unfamiliar territory I was a little worried about the prospect of someone deciding to steal my car, considering its age, it would be fairly easy to make off with. Remembering one of the features of my TwEECer is when the "controller" is removed the computer reverts to whatever is programmed into position one (of five). To make use of this, I had built a "junk tune" that wouldn't allow the car to run, like a slightly oversized key fob, I pocketed the Tweecer controller whenever the car was left out of sight. Thankfully no one bothered the car or its contents during my travels.
While in Vegas car hit the strip (not the drags) for a few trips and was generally great, aside from the black interior and no-A/C.
It was mid-July, in the desert, and no air conditioning you ask? It was actually a little worse than that, I might add the not yet mentioned floor-warming MAC Longtube headers, nor my awesome 1995 Cobra R cowl hood.
I had arrived in Vegas around midnight on the second day, meaning I had crossed the hot spots of Arizona and Nevada after sundown, while it was a little humid from a bit of rain, no big deal. Five days later, my morning departure trip home would be something quite different.
I'd never much noticed it before but the longtubes did make the floor quite warm, enough that I ended up switching out to my "Las Vegas driving shoes" aka pool side flip-flops.
Then came the matter of the Air conditioning, you might be thinking it died trying to cool in the desert, but it never even had the chance, I had killed it months before. During build I was faced with a decision, stemming from servicing the spark plugs, a simple choice, pull the blower, or pull 1 bulky A/C line from the driver's side. I'm sure you can guess my obvious choice, plug accessibility for passenger comfort, I usually just ran the fresh air vents anyway, and so what's the loss?
It turns out that when the early '95 Cobra R race cars were being campaigned, there were driver complaints about the cowl hood extracting engine compartment air and superheating the driver's compartment. Ford then had the hood vents redesigned partway through the racing season, blocking one of the extractors. The very hood I had on my car was one of these later examples, but faced with the heat of my supercharged engine in the desert, my fresh air vents provided nothing but very, very, hot air.
For few hours it took to climb out of the desert of Nevada, through the mountains of Arizona and into relatively better conditions of Utah, things were a quite uncomfortable with the heat. For me it harkened back to times spent in a less friendly desert, only without having to wear body armor this time, for the wife however, this was entirely new and very unpleasant.
Considering the heat, and the multitude of vehicles gushing steam on the side of the road during my climb I was very concerned about the capabilities of my own vehicles cooling system. During the Creston trip I had cooling issues in Canada, so I hoped my switch back to standard pulleys would keep me from boiling over. Keeping out of boost and being careful allowed the radiator to maintain a safe coolant temperature and I made it home without incident.
In all it was a fantastic and exciting trip, the US Interstate system is a dream to drive on, and my car made the whole thing worthwhile.
So what happened in Season 2?
This;
Time for a TKO (Video)
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