tunnel ram results

[F-BIRD'88]

The filters do look good on a street car.

[user-23911]

If i assume my AFR gage is correct, and my motor really does make best power with a mid to high 11's AFratio, What would cause that ? A poor cam choice ? Low compression ? Un efficient combustion ? If i could correct that problem there may be some power unlocked.

It's much easier to assume it's reading wrong.........then investigate WHY it's reading wrong and how much by.

Just the way it is. Some motors make best power on rich side and others on lean.

Because the gauges all read different.


There's nothing worse than having a gauge reading wrong and giving you a false sense of security.......you're better off not having it at all.

[Steve.k]

Steve.k wrote: ↑ Just the way it is. Some motors make best power on rich side and others on lean.
Because the gauges all read different. Thats correct thats why you need to find the correct number. May not be where other engines are. Could be header leaks from slip joints etc.

[F-BIRD'88]

Use the Victor ram tunnel ram with the Street tunnel ram top on it for 2x 4150 carbs. Or make your own top out of flat aluminum plate.
Not that hard.

[prairiehotrodder]

Hey guys, i'm back with more results. It was a fun weekend at the track although traction wasn't as good as it has been before. There was a diesel truck shootout that was ripping up the track and maybe spreading the water around a bit. I made a few changes since last time. Previous best was 9.84 at 135 with very good traction on an early morning run. My best 60 foots are in the 1.42 range.

The changes i did were :

Switched from pump gas to AV gas
installed a wilwood front disc brake kit that knocked off 22 pounds
changed back to my old used Lunati Cam (274/283 110 .748 / .704) set in the R2 position ( i think 106 ICL according to my notes from last time it was in)
changed oil / filter and changed diff oil

I knew the car was working good on friday night when it went 9.95 at 137 with a 1.51 60 foot and no traction compound on the track.
On saturday morning traction was slow to come around as well.
First pass 10.45 at 135 with a 1.57 60 foot
second pass 9.855 at 137.76 1.51
3rd pass 9.789 at 138.7 1.46
(all with no air cleaners and the exhaust off)
put the air cleaners back on 9.874 at 137.16 1.47
took them back off 9.876 at 137.53 1.50
air cleaners back on and exhaust back on 9.899 at 137.33 1.47

If traction would have been good i'm confident my very first pass would have been in the 9.60's range because the car normally slows down through the day as the air gets worse. The motor really seemed to like that Lunati cam. I wasn't going to put it back in but Billy Robinson (Old School) convinced me to give it a try. He was right. The 110 LSA and the bigger spread between the intake and exhaust durations help to keep the power pulling beyond the peak way further. Also when i originally installed the tunnel ram i never gave it a fair test because i swapped cams at the same time. In my analysis so far i'm gonna say the t-ram gained me .16 over the 1050 dominator with the super victor intake. The Lunati cam is worth .06 over the erson cam at least but maybe more. This is about a scientific as i can get !! I have to say a big thanks in the public forum to Billy as well as everyone who has posted in my thread. I'm having a blast and i have big plans for the car this winter.
Brian

[F-BIRD'88]

Good work..Now how does this car run if/when run at "sea level"
Under Corrected Air conditions. Now you know how much corrected Horsepower its making.
And can compare to other dyno tests.

You can look up the historical weather conditions data for that day and hour, online. Then "correct" the indicated test HP to sae conditions.

Any chance to drag test with a forward facing scoop on the carbs.?

[prairiehotrodder]

138.7 mph at 3400 pounds is about 710 hp rear wheel ? In the air that was there. Is that correct ? I'm never gonna be a sea level. That track (mission) is 17 hours from me. Never tried the hood scoop idea yet.

My track (SIR) is about 1600 elevation and the DA on saturday was around 3000 as far as i can tell.

[F-BIRD'88]

138.7 mph at 3400 pounds is about 710 hp rear wheel ? In the air that was there. Is that correct ? I'm never gonna be a sea level. That track (mission) is 17 hours from me. Never tried the hood scoop idea yet.

My track (SIR) is about 1600 elevation and the DA on saturday was around 3000 as far as i can tell.

No this is the raw uncorrected mph/net power.
You then correct the power to SAE standard air conditions to get the SAE corrected horsepower.

The historical weather data is available online for your location and time and the horsepower correction math can also be done online or thru a free phone app.

I have not looked it all up or done the correction but it smells to me like you're doing pretty good , guy.

My math says 701 net (RW) uncorrected power.

[F-BIRD'88]

Wouldn't it be a bit funny if you could get it to run as good (or better) with simple low cost Street friendly Edelbrock 750 (1407) or 650 AVS2 (1905) carbs?

[F-BIRD'88]

By using the weather data for that track and day you can better compare tuning changes +/- progress, by correcting your data to a standard test condition.

Be sure when doing the math that you use the right
required barometer reading (raw or corrected for elevation) for that calc.

[Steve.k]

Excellent results prairiehotrodder!! I remember Joe Sherman said on here he never seen to many engines lose from dual dommies. I took his advice and added nothing but intake and two 1050's and engine made exactly 54 more hp at same rpm. Very cool.

[steve cowan]

Brian,
really good job there and glad you had fun ,
seems a few guys are having good results with avgas,did you get to look at the sparkplugs, looking at plugs on pump fuel i think is difficult to do and i have been looking hard at the track for the last few years,there always seems to be some form of residue no matter how lean you try and run it.
i have not looked at a spark plug from avgas use for a long time so i am just curious.

[prairiehotrodder]

no i never looked at the plugs. I'm not sure even how to do it best. I see guys pulled over on the return road at the end of the track before they even drive back to the pits, is that when i'm supposed to look at the plugs ?
Brian

[77cruiser]

This formula gives flywheel HP have to work backwards.
http://users.erols.com/srweiss/calcmhp.htm

I don't know where this one went?
http://users.erols.com/srweiss/calchpm.htm

[steve cowan]

no i never looked at the plugs. I'm not sure even how to do it best. I see guys pulled over on the return road at the end of the track before they even drive back to the pits, is that when i'm supposed to look at the plugs ?
Brian

the theory is to cut the engine clean after the stripe (finishline) but not recommended in a auto trans but its done all the time.
only then you get to look at the plug for a proper read,if you let the engine idle or have engine braking it will foul the plugs to some degree.
looking at ground strap for spark plug heat range or ignition timing.
looking at the spark plug end of the thread where ground strap is welded onto,looking for fuel mixture or heat down the threads of the spark plugs.
porcelain-salt and pepper speckles due to detonation or to hot a heat range spark plug and also a fuel ring right down the bottom of the spark plug but you require the doctors ear checking light to see down there correctly.
the best thing is if you have the luxury of a good dyno operator and tuner he will get you there or extremely close on your required tune up prior to getting to the track,or if your like me -no money for dyno you can spend $100 ON THE SPARK PLUG LIGHT and learn from your mistakes.