Engine Specs: 455 Buick Motor Holley Commander 950 TBI Intake: TA SP1 Single Plane Power range 0-7500 RPM Heads:TA Performance Aluminum Street Eliminator Valves: Stainless 2.125 Int. 1.750 Exh. CFM: 300+ Int. 230+ Exh. TA head stud kit Headers: TA Shorty Headers 1 7/8 X 3 Camshaft: TA 310 Hydraulic Valve Lift Duration TA Rollers 1.65 @ .050 Advertised Intake Exhaust Intake Exhaust Intake Exhaust Lobe Center Power Range .515" .515" 232 232 284 284 110 2000-6000 Rocker Arms: TA 1313 Roller Rockers 1.65 ratio Cam Bearings: TA 1559 grooved Pistons: TA 1611 JE forged .038, 10:1 comp. Ratio Piston Rings: Total Seal Chrome Moly top ring.030 gap 2nd ring .022 gap Connecting Rods: Crower Sportsman TA main stud kit Ignition Custom Computer controlled HEI, MSD coil, Magnetic pickup and cap Mallory Sidewinder wires Oil Pump: TA high performance oil pump assembly with external regulator Edelbrock 100 HP nitrous shot. Note, no block girdle, or filler, stock crank also, polished and oil holes chamfered. Currently I have the rev limiter via the Commander 950 set at 6400, but I think I bumped up against it with my little 100 HP shot of nitrous in first gear. I just don't want to damage the motor, as I'm pretty happy with it overall. Cam specs indicate 6000 RPM, should I lower the setting? Am I giving up RPM with this setting? Should I set it higher so the motor will run to 6500?
You're using a SP-1 intake on TE heads? I'm wondering about the intake port alignment with that combo.
Bill, I suggest adding the capability to automatically shut off the Nitrous maybe 200 rpm's before the rev. limiter setting.
That's a good suggestion, I guess you can figure out what happened when the ignition came back, Huh? I'll see what I can come up with.
not to get off the subject but how happy are you with the tbi set up? is it the true tbi or the set up with 8 injectors ?
It is the true TBI, 900 CFM 4 barrel 4 injector,Throttle body. And I couldn't be happier with it! It was easy to install, set up, and the best part is it's easy to modify your setup as you make changes to your car, or engine. Another big plus is it puts the fuel and spark control easily in my hands, without tools! it's not like I'm stuck with one setup, either. I can create a whole new profile for any particular type of driving I do if I so desire. The first thing that comes to mind is a more fuel efficient setup, and a performance setup, which I can switch between in a manner of seconds with a download. You guys would probably use something like that for Street/Strip, I would use it for RockCrawling/Sand Dunes. You do not need a computer degree to set it up either. The computer part is actually pretty small. What you really need is familiarization with computers, and knowledge of the engine you are working on. The literature that comes with it covers all facets of operation, in an easy to follow manner. The system has some "Bells and Whistles" to it that make controlling externals a snap, too. All the literature is available from the Holley site if you want to preview it. They also have Tech support if you get stuck on something. So, I guess the short answer is I'm tickled plum to death with it!
I can't beleive no one has had one suggestion to offer up about RPM yet. I figured you guys for sure would know, or have some kind of idea, since you all race your Buicks. I mean, even a "Well, mine has this and that in it and I turn 5800RPM", answer would probably be helpful to get me it the ballpark. Whatever. I'll probably lower the rev limit to 6000 RPM, since that's what the cam goes to.
with your set up I would wind it to no more than 62-300 really no use to go any more I would bet that shift a 5300 and set rev limit to 6200 and you will live a long time. I've had a 455 with kb118 and performer with q-jet balanced but nothing else to 6500 with no problems and the one I have now has a 212s ta cam offy 2-4 intake balanced etc and it's seen 6k more than once I may wind them a little too much though! :3gears:
I assume you have the appropriate valvesprings and spring pressures, since that will help prevent valve float. -Bob C.
Dennis Manner who is the father of the Buick 455 engine once told me that " Horsepower does not kill engines but rpms do".
Yes, the heads are TA Street Eliminator and were put together by TA, based on the parts they used according to my receipt, they are correct and match what they recommend on their website for several of the cam offerings, including mine.
Hmm, perhaps this is why I ask the question in the first place? Do you have any RPM recommendations for me? My last 455 Buick motor had the stock HEI setup on it which I believe is what held me down to around 5300-5500 RPM. So I'd run it to 5200RPM. I don't seem to have that as a limiting factor any longer. In my current setup, I based all my Commander 950 settings off of a base map for a 502 Sysmax package Holley put together. That's where the 6400 RPM rev limit came from. After bumping up against it, with what I would say were less than desirable results, I decided to ask the question, rather than keep it the same. Evidently, cray1801 figured it would be a good idea to shut the nitrous off about 200 RPM before the Rev limit. I completely agree! And I will look into doing so once I get a Rev limit number that is "Good" for my setup, and not something based completely on another motor. Walt Whittman suggests around 6200-6300 Sounds reasonable to me, what do all you think? I want to use all of your experience to help me avoid a catastrophe. Just because I have what I consider to be allot of money in my motor doesn't mean when it blows, I'll have allot to fix it. I have based how this motor went together on knowledge I have gathered here, and from Mike at TA (and Dave when he was there). I believe it to be a well put together package. This is just one of the finishing touches that hopefully will KEEP it a well put together package , and not scattered all over the side of a hill somewhere. I do intend to take the motor to Pro Dyno in Tempe and put it on their chassis dyno to get a better idea of what it is capable of. Once I find out where the horsepower peaks, I guess I will know for sure where to set the Rev limit, until then though, having a number high enough to peak horsepower but low enough to preserve the engine would be a pretty wise thing to do. Question Now is, what's that "Number"? (This is where you guys come in with your wealth of knowledge.) :laugh:
With the good rods and lightweight pistons I think you will run out of cam before you endanger the bottom end. The only variable is how well the oiling system is working. Assuming the oiling is up to snuff, I'd set the limit based on shift point ,which I can't see being much over 6000.
Everything depends For drag race applications, the more HP the better your bottom end has to be. With Case crank and no girdle, 6000 to 6500 max. \max.\ max. in short bursts. For longivity and dependability 5800 to 6000 it should enjoy a relatively long fruitful existence. Those big crank journels are killer at RPM's higher than 6000 RPM. Weekender
