Dyno - Sunday! Any tips ?

This Sunday I am taking the GS for a dyno . I get 2 times to play with this. Change timing , plugs etc .
Thinking run 1 time and see , and then the second time ......................... ?

Thanx to all for your imput !!:laugh: :laugh: :TU:

 

Bruce, are you just running straight 92 octane pump gas? If so, you might try adding a some Xylene to your tank for the second run and turn up your timing a lit bit! It makes for a great octane booster, and its fairly economical.

I used to run it in my GN before I got alky injection, and my neighbor runs it in his 71 GTO and 94 ZR-1 all the time.

Makes for a little "extra" fun on the street, and lets you run it with the same types of octane they used to run!:TU:

Chris

 

:TU: Chris thanx for the tip and product info! I have been using 92 pump gas w/ 5 gallons leaded 102 octane added when I want to play over the weekend.

Also I put octane boost in every tank. The timing I will check out here before I go . Factory timing scale and no dial down timing light yet. Need to go to Sears and buy one yet.

Thanx for the tips !:beer :TU:

 

For some reason I can't justiry buying a $70 advanced timing light when I can just get a cheaper one that works just as well...


Bruce,

petal to the metal:Brow:

 

Adam I have a regular timing light but with this cam I will need to dial the timing in at 30 degrees at 1500 .

Wish I could get by with stock but you'll understand better when ya come to the party . I have to see what this motor does on the dyno. It was sold to me with no dyno sheets. Talk is cheap ........................ and money talks !


:laugh: :TU:

 

How much for dyno time??

 

OUCH! $$$$!!!

Xylene and Toulene are two of the active ingredients in octane boost, and are a lot cheaper! Check out turbobuick.com and do a search on Xylene and you will find gobs of info.

Xylene is 117 octane, and runs about $5 gallon at a paint or supply store (or Ace, Home Depot, etc.). I usually mix anywhere from 1 part Xylene to 3 parts gas to 1 part Xylene to 4 parts gas (some people go 1 to 2!), and then put in a little Marvel Mystery Oil for added lubrication. At 1 to 4, you can add 3 gallons of Zylene for 12 gallons of gas, total octane would be 97.

Not sure what you pay for 102, but here it is about $5 to $6, or the same as Xylene. If you add 3 gallons of 102 to the 12 gallons of pump gas, you only get 94 octane! You would have to have equal quantities of 102 and 92 to get 97 octane, which would be pretty expensive for a full tank! And that isn't even counting the cost of the octane boost, which barely evens boost anything if you add to a full tank.

Check it out and you will be a believer! Of course, you will find yourself never leaving home without a funnel with a small rubber hose on the end, just in case of an emergency!

Chris

 

Remember to remove your air cleaner. The higher hp the engine the bigger the difference. On my under-carbed car, it made an 11hp at the rear wheels difference.

 

Chris I printed off the info ! Sounds a lot cheaper . I will look into it soon . Thanx Chris .

Adam - For 2 pulls it will be 50.00 .:gt: :TU:

 

Bruce,

You should check into the price for additional pulls. When I did my GN this spring, it was around $70 for 3, but additional pulls were only $5 each, since most of the time is actually spent loading the car, not doing the actual pull. I think I did 5 or 6:grin:

If you have to add the Xylene while it is on the Dyno, be sure to rock the car side to side a little to slosh it around and mix it up a little before your next run. It is best to drive around a little, so if you always run with extra octane on the street anyway, you might as well have it in there for all of the runs. Good insurance against detonation no matter what.

Chris

 

$50? I'd pay it..just to see what it could do.

 

Chris I will be asking that question and also bringing the toolbox to make a few adjustments as i go . Will let everyone know what the results are when I get home Sunday .

Adam your right for 50.00 i think it's worth it also. Too bad it wasn't the weekend of the party ! :laugh:


:laugh: :laugh: :TU:

 

I believe the octane scale stops at 100. Technically, there is no such thing as 117 octane. Perhaps a performance number eqivalence of 117?

Suggest avgas 100ll for a shot of anti knock tetra pb if no cat converter is involved. About 2- 2.25 per gal. at rural airports.

 

It sounds like you are just going to test, to see what the dyno #'s are. MY OPINION- If that's true, why bother with octane booster? See what the engine can do as it is. I like to be able to brag about what the car IS capable of, not what it COULD BE capable of. Why not drop the tailpipes and run open headers? Because that's not how you usually run. If you are always gonna run the xylene, then that's fine.

Off my soapbox.

I have been told by dyno experts (and can verify this myself after several dyno visits) that you always make the most HP/torque on the first run. For whatever reason (heat?), the second run produces less HP than the first. If you intend to make several pulls and change tuning (jetting, timing, etc.) be sure to disregard the first run, otherwise you will think you made a bad adjustment when you might have actually made a good adjustment. Make 1 run, throw out the numbers, then make a second run and then make tuning adjustments to see if they help.

If you are only there to see what it can do now, well then just strap in and have fun!

-Bob Cunningham

 

I had never heard that the octane scale stops at 100 before. Doesn't seem right, since they sell 110 and 116 octane Race gas at the track. Here is some info I found on gnttype.org on avgas 100ll:

6.19 Are aviation gasoline octane numbers comparable?

Aviation gasolines were all highly leaded and graded using two numbers, with
common grades being 80/87, 100/130, and 115/145 [109,110]. The first number is
the Aviation rating ( aka Lean Mixture rating ), and the second number is the
Supercharge rating ( aka Rich Mixture rating ). In the 1970s a new grade,
100LL ( low lead = 0.53mlTEL/L instead of 1.06mlTEL/L) was introduced to
replace the 80/87 and 100/130. Soon after the introduction, there was a
spate of plug fouling, and high cylinder head temperatures resulting in
cracked cylinder heads [110]. The old 80/87 grade was reintroduced on a
limited scale. The Aviation Rating is determined using the automotive Motor
Octane test procedure, and then converted to an Aviation Number using a
table in the method. Aviation Numbers below 100 are Octane numbers, while
numbers above 100 are Performance numbers. There is usually only 1 - 2
Octane units different to the Motor value up to 100, but Performance numbers
varies significantly above that eg 110 MON = 128 Performance number.


They have a couple of good articles there on creating high octane gas as well, mostly by using Toulene or Xylene. Good reading!

Here

HTH, Chris

 

Instead of disregarding the first run, maybe just keep track of the temperatures at the begining of each run? I remember an article (HRM or CC i think) a while back and they noted that coolant temp made a definite impact on power. If the dyno place has water for you to cool down the rad after each run so you're starting at the same temp each time. I guess to be realistic try to get it about the same temp as your normal driving temp, or if you want as much hp as possible on paper, get it a few degrees cooler.
I don't know, it might just make a big puddle and they might not let you do it, but it's worth asking about if it will help the consistancy of the runs.

 

Thanx for the tip's and your help . I have decided to run the pump gas I normally use and bring my tool box if I decide to make any adjustments before the 2nd Dyno .

I could make the fuel changes but I wanna see what we have from a turn key position at this time.

We'll be home Sunday with the Dyno sheets!:laugh:



:bglasses: :bglasses:


:TU:

 

First, the best bottled octane boosters I have seen will raise your octane at best from 87 to 87.7 less if you are starting with say 93. Not a very good bang for the buck. I have had great experiene with Xylene and Marvels Mystry Oil for a real octane boost with my GN. Octane that could be seen at the dragstrip in terms of mph and additional detonation tolerence at higher boost levels. I have used 5 gallons to a tank capped with 94 pump gas for about 100 octane mix. Turning up the boost would be kind if like having variable compression with a naturally aspired motor.

Second, I don't know what your compression and build up is but something to consider is that if your motor is set up for pump gas more octane might not provide you any extra power. I have heard before of people putting pump gas motors on dynos and getting better pulls out of them before adding race fuel even after timing etc adjustments. It just depends on lots of small variables your setup compression timing cooling system igntion. More octane only helps if your setup needs it. I am no guru by any means just food for thought.

 

I'm definately no expert...matter of fact...I'm blissfully ignorant when it comes to "gas theory". :gt:
.... but when I was racing religously about 6 or so years ago, I always just ran 94 in my street/strip cars.
I was thinking about filling up with CAM2 at Norwalk one night because I needed gas, and most of the guys I was with said it wouldn't help any, and probably would actually slow me down because I was running basically stock compression. (I think they said it would burn too slow or something??)

I didn't get any CAM2 that night, so I don't know if they were right, but I am curious as to what the others here think about it.
o No:

 

The GS slows almost a .10 with straight 110 in it, I run 5 gal of 110 in every other tank. Its 10 to 1 with no camber work, I have only heard a ping with the AC on and straight pump gas.

Bruce, set the timing to 34 @ 3000 rpm, leave the air cleaner on and see where the wide band is, if its rich pull the air cleaner for the second pass. Don't jet the carb for the dyno, jet it for MPH at the track, Mandys GS read rich on both pulls last year, the jetting is right on for the track.

Mandys car is made 365hp and 465lbs, thats what you need to beat..... :TU: