|11-12-2013 02:32 PM|
I am getting on with my engine. seem to be going around in circles on here. I cant change my bottom pulley. so I have to change my top each time I want a boost change. am thinking of ordered up a 47 and 43 top pulley but waiting for the blower shop to get back to me on expected boost based on what I have told them with my engine figures and current blower sizes.
prob go back to dyno over xmas. I like the dyno for testing out. more safer and controlled rather than hoping and screaming down a track. I will do that when its set up.
|11-06-2013 09:08 PM|
Believe me 671 I can relate on not having a local track They closed each and every track within a 100+ miles of my house and sometimes for me it's a 2 day routine to simply go make a few passes, it's a real pita...
BUT IT'S WORTH IT WHEN YOUR THERE AND DOING IT
Here's my passes from Sat, make no mistake these 351w can kick some *** when they're making power
|11-06-2013 09:06 AM|
The simple fact that you are missing the obvious as afars as waht new pulleys to order
shows that you don't the tuning experience and need to creep up on boost and power
a bit at a time.
its is simple: Order anew 51 tooth crank pulley and a new 45 tooth blower pulley.
Now with alll the pulleys you will be able to achieve 11% under drive AND 1 to 1 ratio and 11% over drive
on the blower.
Now you have 3 different progressive boost levels to tune with.
With out KNOWN verified standardized accurate dyno calibration set up and test operating condition parameters
and known test correction factors (weather etc) and the dyno correction factors used?
Those numbers are just numbers that cannot be compared to any other dyno test or someone elses car.
What was the AFR's, jetting and timing and power curves and boost curves from each dyno test
temp, humidity, AIT's etc etc..
garbage in garbage out. The numbes from the current 7psi tests are low even for that dyno.
Do not assume the engine is correct. Do not progress ( add boost) until the engine is correct @ 7psi.
they are only cast pistons.
The higher the boost the more critical the tune up.
|11-06-2013 08:27 AM|
Changing the pulleys will not make the track any closer to you.
It will still be 3 hours away.
Pulleys are simple .. swap the top and bottom pulleys.
if all you want is a dyno test number for bragging rights (I have X amount of horsepower) then just get the dyno operators to
change the dyno test parameters to get you a dyno slip that you like.
|11-06-2013 08:14 AM|
No point . As the 1/4 mile track is 3. Hrs from me . Dyno wouldn't be that far out -ie 150 bhp more is still only. 480 bhp . Which is where I wanted to start from . 550--600 bhp is more than do able with what ive built . Eveerything is new . All readings at dyno where good . Have plenty more to go . Need more boost . Some. Standard 350s are making this power,
Need help on pulleys if you can ,
Point taken though and I will go to the track . Once im seeing more power
|11-06-2013 07:45 AM|
Why don't you run it down the drag strip as is so that then the current power reading from the dyno has some real meaning and relative actual car/engine performance reference based on the track 1/4 mile MPH and car weight.?
Any high boost power testing should be done on high octane gasoline , first.
The creep up on the "pump gas" tune up (timing) while carefully watching for knock.
Detonation must be avoided.
Right now all you have is a chassis dyno generated power number that can only be referenced + or - relevant to another dyno test
on that same dyno.
A day at the local track drag testing it at its current 7psi tune up will give that number from the dyno some real performance meaning. And give you some seat time, to learn to use the engine power in a safe manor.
And allow you to verify the engines real world performance and reliability.
make it go fast down the track @ 7psi. and
(Sort out the new car bugs, etc). Now is the time to find and sort out the little stuff, not when it is wound up tight at 12+PSI boost-tuneup.
Then take it back to the dyno and creep up on a high boost tune (pulley swap)
|11-06-2013 02:35 AM|
|mustang 671||Yes they are opening fully . Pri jets 72 second jets 78 did change secoundaries to 82 but no power increase just highest air fuel mix .ign mapped by dyno guys for peak bhp . Gave it what it wanted . Needs more boost . Any ideas on pulleys ? Fuel prressure maintained .|
|11-06-2013 01:25 AM|
Carb pri and sec jetting? timing?
|11-05-2013 01:50 PM|
|11-05-2013 01:46 PM|
have just posted below my auto c6 spec. its all new and good quality stuff.
tyres are brand new. they sprayed some goo onto the rollers for it to grip.
the exhaust I also mentioned. but agree if it had a stainless all the way through im sure it would flow better. but it is big bore . and I have nice long headers. large bore aswell.
|11-05-2013 01:38 PM|
hi all and those just following . I really could do with some input on the following. and I know it may be a wet finger in the air and hope ????
so currently I have a 45 tooth bottom and 51 tooth top pulley. I got 7psi at 6000rpm but had so much more to go and only produced 330bhp.
have spoken with the dyno guys again today and also a supplier over your neck of the woods who can supply me with a 42 tooth cog for $115 + delivery which isn't bad. my questions is , can anyone hazard a good guess- work out? how much boost that would get me to ? so 45 bottom and 42 top
my engine started at 7.48to1 comp ratio but since then I have changed from a felpro normal head gasket to a felpro mls one. nothing else has been changed apart from it being homed out just slightly and a bit of piston to bore wear but prob nothing to be honest as the engine hasn't had much use. the orginal block is 30 thou over and I have kb hyper pistons - but I do now have a new crane custom grind cam which I posted about earlier which is a roller cam.
I have large headers which collect and go into 3" exhausts . under and out the back. the car was for racing before I imported it so it has a large dual exhaust.
I have a c6 with a high stall b+m torque converter. Been uprated with reverse manual shift pattern body.
my thoughts are that the combi would give around 10-12 psi ? which would be a lot better , I will have the water inj running with this higher boost. I can easily get hold of 99 octane fuel to use. only 5p a litre more . but still bloody £6.58 a gallon
|11-05-2013 01:16 PM|
thanks for the comment. I can get a different size belt so haven't got any issues with the tensioning luckily. that's interesting you mention it could be a smaller case blower. will look into that. ta
also I looked at my blower before I brought it years ago and also more recently when I o-ringed out the inlet manifold. the rotors are good. no scores. no leaks from the blower either.
|11-05-2013 01:14 PM|
hi pro street rob
the sierra sounds nice on the rd. and congrats on those times. must be hard when its raining. here in the uk the weather has turned so don't expect I will be getting out much for a few months, prob not a bad thing. try and get some nice cold dry days and put some miles o it before the summer heat comes. less chance of it getting too hot. your pulley sizes are interesting. seems the charts aren't any use and just a very very rough guide.
|11-03-2013 11:53 AM|
Somewhere above you were talking about the boost not being what the charts showed. It's possible you have a small case 6-71. Not a problem but you just have to spin it faster. Hopefully your blower is not messed up. I've run into at least 6 this year with too little clearance on the rear of the rotors resulting in a galled case and rotors.
Since you can't change the bottom pulley the only choice is the top one. You may have to make a spacer under the blower. 1/8, 3/16 and 1/4 in are common SAE sizes. Adjust for metric material if you need to. The reason for the spacers is that you you may run out of room for adjustment on the idler.
|11-02-2013 10:29 PM|
Deep Staged by mistake on the first pass and ran a 10.92, then ran a 10.81 and the best ET of the day was 10.70 (it went 10.66 & 10.61 at Atco earlier this year) Atco is a much better track and closer to sea level where Island is up in the mountains at higher elevation so I guess I cant complain since we took it home in one piece
As for the Street Beast, my Sierra makes crazy power so I dont need much boost. I'm running a 56 T Upper Pulley + 52T Lower Pulley =’s 8 lbs of Boost @ 6,000 RPM (-5.5 Underdriven). At that set up the compression correction works out to 13.1 Compression. If I switch the pulleys around it's 12 lbs of Boost @ 6,000 RPM (+5.8 Overdriven) With that set up the compression correction works out to be 15.1
Mine sounds totally different than yours, I made this a few days ago on my phone. Just a little put put around town...
A few pics from the track today
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