Running 7.20's you should be 6.80 on a 125hp shot. AND STAY AWAY FROM RUNNING FROM THAT SAFE RUNNING RICH CRAP! With all that extra fuel, you might as well spray a fire extinguisher in it with the nitrous because thats all its doing is keeping it from burning. If you haven't made it out of the 7's on spray with a 150 shot don't go any higher until you do. It should go an easy 6.80's with no tuning. HOw about this. If you want to be safe. YOu have the Big Sgot NOS kit RIght? If you do put the .091 jet on the nitrous side and the .093 on the fuel side and start at 6 psi on the fuel. That will be like a 240 HP shot and take out 8 degrees of timing. total timing with the nitrous should be about 28-26 degrees. Thats alot safer than trying a 400 hp shot. You said: "Well the nitrous fuel pressure is about 7 pounds with the fuel jet on the 400 horse pill instead of the 300 horse pill. i like a little more fuel." Did you mean just on the fuel side of the plate? What EXACTLY are you running for jets sizes in the nitrous plate? What are all the jet sizes you got with the kit?
You can do as much damage with to much fuel as to little like Rick says you'll put the put the fire out then the unburnt fuel basically hydraulics the motor then you compress the ring lands which pinces the ring so they don't seal to the cylinder and allows oil into the chamber oil and nos don't mix oil will cause detonation then you have burnt pistons.I also believe when you pick a cam for nos you want to cam it for the hp you expect to make on nos so if you plan on 900 hp on nos the cam should be able to support this hp level.The motor will be sluggish on motor alone but when you hit the can it will come alive.When it comes to jetting the nos DON'T BE A HERO start small and work your way up you will be alot happier with nos 400 hp nos is a big kit you need to be very knowlegable with nos to run this hp level you will burn up a motor fast at this level
Thanks for the advice. I currently have the plate jetted at the 300 horsepower setting with the max horse pill in the fuel. I will try and turn the fuel pressure down on the fuel solenoid and see where it will go. I hope that this thing will run 6.80's on its own and then I can go to the gas on it. The motor is plenty strong and I would like to see where it can really go on horsepower. Since the changes I have not ran the motor. I am planning on going to the track sometime this week and see just where it will go on motor and then tune it for nitrous. That is something that I have never did. I really want to put a powerglide in the car and see how it acts with that and nitrous. Everyone is telling me that is what the car needs and I want to see. What is your opinion on the powerglide? Would I need more gear? I have a powerglide with the transbrake and 4000 converter. And can u put coilovers on a stock suspension with just a tracking bar?
I would start a little smaller on the nitrous jetting and definitely start with what the recommended jetting is, trust me its rich enough already unless you like to go slow. If you try the next size up HP fuel jet (say 350hp) from where you nitrous jet is( say 300hp), you would make more power with the 150 hp shot jetted correctly and it would be a safe starting point. Running it that rich on the plate with that much nitrous will score your ring and ruin your ring seal. There alot of tricks to learn with Nitrous and starting on a big shot is a hard way to learn. Its hard enough sometime just go up from 150-175 shot that runs good and your going straight to a 300. Again, I LIKE IT, but its really a bad way to do it. :blast: I'm behind you all the way with getting that motor tunned in better. On the glide issue, its more about weight than anything. The cut off for a glide is about 2800 lbs. If your running nitrous and only 1/8 mi you can go to 3200lb. I run my glide with 4.30 gears but it hasn't work out as well as I liked since I can't run 1/4 mi with it and I can't get the 60 ft I wont without sacrificing top end. I ran into the same deal. Everyone was telling me to just go to a glide so I spent $2000 and changed the gear in the rear and now I wish I would have just changed the gear and kept the th400. I went faster with less nitrous with the th400 but the car was sooooooo much better to drive. It was pretty hairy in the 60ft with the th400 and the 3.90 gears but I could have fixed that with 3.70's or 3.55's and gone just as fast if not faster. If you insist on a glide I'd go with 4.56 gears maybe 4.30's if you were light enough. On that 4000 stall, what is it set up for exactly. Most of the time a "4000" stall behind a nitroused Buick means 5000+ so If it will hold to a 4500 flash on nitrous you'd be ok otherwise forget it. Speaking of stall. How much rpm drop do you get when you shift going down the track?
The converter was built tight 4000 for nitroused applications. The car is a stock bodied and suspinsion buick regal. I have gotten it to work really well with the power of the car. I will try and go to the bottom of jetting on nos and upgrade until a fall off in et.
I hope things start coming together for you with your combination. Let me know how test and tune goes. Good Luck. :TU:
Went to the track on sunday and the motor went only 7.41. I cant figure it out. What is the timing suppose to be set at with this combination. I am about ready to take it out and start all over again. the motor feels stronger but it is not showing the numbers. I put jet extensions in the front and back of the carb and the back stopped pumping out of the squirter. Do I need to tear the top back apart and have it checked for anything in particular. Would a not ported intake on ported heads stop the performance. I really need some kind of help.
Where is the cam installed? I'd be willing to assume you didn't degree it when you assembled the Motor.......
36-38 degrees total timing w/11.0 comp and that large of a cam. Too much timing will slow it down just as too little will. timing should be checking while holding the rpms up to where the distributor holds max timing advance. Make sure your gasket isn't blocking/misaligned the hole at the bottom of the bowl where it lines up at between the bowl and the metering plate. I've see cases where you had to pull up on the bowl when tightening to get the feed holes to line up for the accellerator pump. That cam should be installed with a 104 degree intake center line. Just because its installed 4 degrees advanced on the timing chain doesn't mean its right. It could be off a tooth or the cam could be off or the gear set could be machined wrong. With racing parts, machine work, assembly; if it can go wrong it will so double check everything. On your intake. If it is a newer version TA intake, no you should not have to port match it. If it did not come with CNC'd ports at the intake flange, it needs port matched. But worst case I can't see it slowing you down more than .20 . If it sounds strong and is very responsive, I would look at three things. - Too much total timing. It will not detonate with that low of comp with that cam on iron heads. - Too much advance on the cam installation. - Running the carb out of fuel. This being the least of possibilities, but a consideration.
A Quick Test..... An idea to see if your cam might be degreed in close. My motor at 11.6 comp with a 268 degree intake installed in a 108 Intake C/L had about 185 psi cranking compression. If your sure you only have about 11.0 compression, with that large of a cam, you should have the same or less than my motor. Unless your gauge is way off. If you have alot more than 185 your cam is too far advanced and needs fixed. If its wrong, make sure to use a degree wheel to dial it in. I have a degreeing kit. If this checks good than put a timing light on it and do a couple of quick revs to @5000 to make sure your timing isn't going anywhere or past 36-38 degrees.
I will try and get the cam degreed in on a 104 centerline and then check the timing for how much. I just brought a new timing light yesterday for this purpose. I discovered a bad vaccum leak when I was at the track.
If you're saying you never degreed the cam before now,Do it before you do anything else. Don't play with jetting,Don't play with timing........You're missing alot more power than a few degrees of timing or a couple of jet sizes can account for. I've seen these timing sets 10 degrees advanced when the 4 degree keyway was used. You'll be happy once you do it.
Vaccum??? Who are you trying to kidd here? There ain't no vaccum on that thing! You got the wrong cam if you got vaccum. J.K. :laugh: Anywho. Definitely get that cam straight. Otherwise your just waisting your time and money doing everything else. With your setup it would be money well spent if you got a start/timing retard box and just locked-out the timing advance so it was fixed. THat way you could take out timing for easy starts and take out timing for the nitrous. **** On the timing subject***** If your spraying alot of nitrous and taking out alot of timing with a box you need to check the phasing of your distributor. If it is off, it will try to fire the next cylinder in the direction of rotation. More to follow if anyones interested. Its mainly a problem on stock distibutors.
I am calling the mechanic today and see if we can degree the cam before friday. I have the digital 6 plus with start retard and timing control for the nitrous. I have the MSD distributor in the motor with it locked out. That is why I know that the timing was not accurate. It was at total 20 degrees of timing. I have a vaccum hose running from the back of the intake into the PCV valve to releave some motor pressure as well as the tubes out of the valve covers into the headers. How hard is it to degree a camshaft in.
It not hard just a little time consuming. The chain sprocket on the crank can be a bit of a pain if you have to make a couple of adjustments. What did you mean it had 20 degrees total timing?
With the distributor locked out and the car at 3000 rpm the timing read between 17 to 20 degrees of timing on motor. I would like to degree the camshaft in so I could see some added power that I am missing out on. I really hope that this thing will go into the 6's in the 1/8th mile on its own. I got the timing set at 36 degrees and 28 degrees od nitrous.
OK, I'm sure its just something you left out in how you explained it, but, if your reading 17-20 degrees of timing then how can it be set at 36?
I just set the timing at 36 degrees this weekend. I brought a new timing light and when I shot it on the balancer it was reading 17-20 degrees then I set it at 36 degrees after u told me where it was suppose to be.
Is that all that was wrong...... Well, that would explain were most of your power went. 16 Degrees off will kill alot of HP. With your timing locked out would explain why it still felt good on the launch and then fell on its face. If you haven't raced it with the timing right, i'd give it run and see what you get. Hopefully it was just your timing being off. Keep us posted.... :TU:
Now that you have the timing set.I think you need to check the rotor phasing as Rick mentioned on a earlier post I have seen this cause problems with all distributors.You need to drill a hole in line with #1 cylinder on the top of the cap then shine the timing light down the hole and check the alignment the rotor tip should be in the center of the terminal If there is a problem and you have a msd dist you need to get their adjustable rotor and line every body up I think this rotor will also work on a stock dist I am not sure of this I have only used these on a msd dist.When you hook up the nos you will need to adjust this with the timing retarded so every thing is right when your on the can
