[Lloyd-TX]

Another awesome build, Dennis! You are an awesome Pontiacker my friend!

[Lloyd-TX]

On another note, I've been wondering "out loud" how much RW power and torque would be lost if you were running gennie OEM or Waldron mufflers? I am so very partial to the old school oval reverse flow mufflers on a non-catalyst car!

Would Tom Hand have any information in this regard?

[unruhjonny]

/\/\ the "Hot Rod" guys have done several muffler dyno shoot outs... maybe they have something that should give you an idea?

[SD455DJ]

Originally Posted by Lloyd-TX

On another note, I've been wondering "out loud" how much RW power and torque would be lost if you were running gennie OEM or Waldron mufflers? I am so very partial to the old school oval reverse flow mufflers on a non-catalyst car!

Would Tom Hand have any information in this regard?

Lloyd, The only 'real world' comparison I have is with my RAIV Judge. It had an old Maramount (sp?) system (kink-bent 2 1/4" with 20" case 'turbo' style mufflers) and with the original motor ran 13.70's at 103 mph average. I swapped in a Torq-Tech 2 1/2" mandrel bent system with 18" long DynoMax UltraFlo mufflers and the performance improved to 13.50's at 106 mph. I'm sure there is more potential gains and it has run 12.80's at 110 mph with the replacement RAIV engine (borrowed from another RAIV GTO) with the same exhaust system.

I believe there is at least a 10-15 RWHP reduction going from DynoMax UltraFlo's to the SuperTurbo's, and another 10-15 hp reduction going to the factory (Waldron/Gardner) mufflers.

It would be an interesting test.

Dennis

[Lloyd-TX]

Originally Posted by SD455DJ

Lloyd, The only 'real world' comparison I have is with my RAIV Judge. It had an old Maramount (sp?) system (kink-bent 2 1/4" with 20" case 'turbo' style mufflers) and with the original motor ran 13.70's at 103 mph average. I swapped in a Torq-Tech 2 1/2" mandrel bent system with 18" long DynoMax UltraFlo mufflers and the performance improved to 13.50's at 106 mph. I'm sure there is more potential gains and it has run 12.80's at 110 mph with the replacement RAIV engine (borrowed from another RAIV GTO) with the same exhaust system.

I believe there is at least a 10-15 RWHP reduction going from DynoMax UltraFlo's to the SuperTurbo's, and another 10-15 hp reduction going to the factory (Waldron/Gardner) mufflers.

It would be an interesting test.

Dennis

Thanks for the information, Dennis. Take care.

[SD455DJ]

Hmm...come to think of it, I have a pair of new (probably close to 15 years old now!) in the box 20" DynoMax SuperTurbo mufflers (17749) that are 9 3/4" x 4 1/4" ovals by 20" case length. The UltraFlo's have the same oval dimensions, just a shorter 18" case. I read that the Dynomax SuperTurbo's can support up to 700 cfm and the UltraFlo's up to 2000 cfm. That gives you an idea of the restriction built into the Turbo muffler "S" shaped flow path vs. the straight through of the UltraFlo. I'm quite sure there would be a performance penalty changing to Super Turbos's. I plan on using the 17749 mufflers on my '71 Bonneville (stock 455 4-bbl) when I upgrade from the teenie 2" system with Midas choker mufflers that is on there now.

Thanks for the compliments Lloyd!

Dennis

[SD455DJ]

Finally got the correct black air cleaner lid to replace the old beat up chrome lid on it temporarily. Now it looks like what a 330 hp 400 should in a Tempest/LeMans.

Dennis

[Rocky Rotella]

Originally Posted by SD455DJ

Got the fuel system all set. The car has a Tanks, Inc. gas tank with the internal pump along with a Holley pressure regulator and an inline fuel pressure gauge in front of the tank. The Tempest had a big Holley 850 on it when I bought it and the pressure was set to 8-9 psi, too much for a Rochester Q-jet, so we adjusted it down to 5.5 psi. The fuel will be pushed to a stock deep reservoir mechanical pump.

Dennis,

I'm interested in your fuel system. Could you elaborate on its design and components?

What pump is in the Tank's Inc tank?

Are you using the stock 3/8-inch fuel line from the regulator forward or did you increase its size?

Is there any reason you kept the stock mechanical pump?

Are you using any type of return path? And if so what size?

[SD455DJ]

Rocky,

The previous owner installed a Tanks Inc. TM34D-T tank with the GPA-2 internal fuel pump. He replaced the stock fuel lines with 1/2" steel and added a 5/16" steel return line from the stock fuel pump location back to the tank. He added a maze of steel braided lines out of the tank to the steel lines and installed an in-line adjustable regulator (5.5 psi) and fuel pressure gauge just in front of the tank over the rear axle. We (as well as he) kept a mechanical fuel pump on the motor.

Dennis

[HWYSTR455]

Originally Posted by SD455DJ

Rocky,

…. He added a maze of steel braided lines out of the tank to the steel lines and installed an in-line adjustable regulator (5.5 psi) and fuel pressure gauge just in front of the tank over the rear axle. We (as well as he) kept a mechanical fuel pump on the motor.

Dennis

Hm, like he mounted it close to the OE fuel separator? In that area? Got a pic?

That actually sounds like a good place to mount one if you're trying to hide it.


.

[SD455DJ]

Originally Posted by HWYSTR455

Hm, like he mounted it close to the OE fuel separator? In that area? Got a pic?

That actually sounds like a good place to mount one if you're trying to hide it.


.

HWYSTR455,

Well, here's the only pic I have at the moment. I should have taken a few more when we were installing the exhaust system. The regulator is to the left and kind of hard to see and the tank is at the bottom of pic. We did adjust the pressure down to 5.5 psi from 7.5 it was set at for a Holley carb.

Dennis

[HWYSTR455]

Ah, I see now, on the trunk side. Guess he ran the lines like that to include the gauge back there. I bet that would clean up easy with aluminum lines and tube nuts.

There's not a lot of room back there, the housing can swing up and make contact if it's not tight.


.

[unruhjonny]

wow - that is a maze of braided hoses alright!!

[SD455DJ]

Originally Posted by HWYSTR455

Ah, I see now, on the trunk side. Guess he ran the lines like that to include the gauge back there. I bet that would clean up easy with aluminum lines and tube nuts.

There's not a lot of room back there, the housing can swing up and make contact if it's not tight.


.

Yeah, I hear what you are saying...but, we checked the rear end travel for any conflict and all the hardware and lines were well out of the way...just not pretty. I like your idea to clean things up with more hard lines that are direct. We did also remove a couple mud-dauber nests when we were back there. Those came from its few years down in Florida before I got it.

I found a few more pictures that show the 'plumbing'.

Dennis

[Rocky Rotella]

Thanks, Dennis. I'm looking to move to a Tanks Inc. setup in my Trans Am and would prefer to have a setup similar to yours. This helps!

[SD455DJ]

Rocky,

Glad to help. I'm sure you could improve on the installation a bit.

Dennis

[SD455DJ]

Dan and I finally had the opportunity to run the ’70 Tempest with the XV code 400 (330 hp/430 lb-ft torque) at the May 12 & 13th F.A.S.T. race at Martin US-131 Raceway Park. This is the first time it’s been out in public since I got the car 4 years ago (already!), also the first time on the dragstrip, so, we were pretty excited and nervous how it would perform. The engine was dyno’d over 2 ½ years ago, so, after a quick once over of the fluid levels, bolts, lugnuts, brakes, fuel lines, hose clamps, double checking the timing (36 degrees all in by 3200 rpm), and pumping up the G70’s to 40 lbs. all around, we were ready to race. Oh, we added 6 gal. of 110 leaded race gas ($72!!!) to the 14 gal. of Shell 93 E10 ($5.10/gal.) just to guard against any potential detonation as it was 88 degrees both days! We left the carb jetting alone from the dyno session (73 jets/43 rods primaries & CG (.0774M tip) secondary rods on a ‘K’ hanger) and never touched again over the next 2 days (plugs read great each day). The 3.42 gears are definitely not ideal for racing (went through the traps at around 4900 rpm), but it is a street car, not purpose built and/or optimized for the pure stock drags…however, 3.73’s or 3.90’s would be much better suited for the track.

The three best passes were 13.1843 @ 103.88 mph, 13.2045 @ 103.09 mph, and 13.2182 @ 102.90 mph in the oppressive heat with OK 1.92 – 1.97 sec. 60’ times. The worst times were in the 13.40’s when the line was slick and spun hard. It was fairly low humidity on Thursday, but shot up on Friday. I heard that the DA’s were 2200’ on Thursday afternoon and over 3500’ on Friday afternoon (unsubstantiated – maybe someone could verify?). Regardless, we are very happy with the cars performance, right where we were hoping it to run.

Another surprise was the weight…3815 lbs. with me in it…way heavier than I was expecting…by 150 lbs.! So the AMA weights are real close for this car as optioned (3643 lbs. + 165 lbs. (me) = 3808 lbs.) with a full tank of gas, no spare tire though (in the trunk that is…not my waist). It’s still 300 lbs. lighter than my ’70 RAIV/TH400 Judge (OPH – Roger – you were right on with the weight!).

We’re quite confident with some further sorting out of the suspension (pretty stiff and little to no front end lift) and cooler weather, it could run high 12’s. The lower mph is indicative of the small valves (lower air flow) of the heads, the log exhaust manifolds with the 2.1” outlets, and fighting the 3.42 gears. But, it was a blast getting back on the track as it’s been since 2007 (15 years) the last time I raced in the pure stocks (or anything for that matter!).

Dennis

[b-man]

Amazing performance.

It looks so sweet in that color, more beautiful than one might imagine. Really compliments the lines of that body style, a ‘70 Tempest never looked better.

Congratulations on everything you guys have done with that car.

[SD455DJ]

Thanks B-man!

Here's a close-up of the scale readout. It was pretty windy so the scale would vary about 100 lbs. plus or minus, so you had to time moving onto it when the readout was close to zero, or you would get whatever the reading was added or deducted from the real weight...made it a fun challenge! So the scale read +10 lbs. when I rolled on to the scale.

Dennis

[AG]

Wow, that is a light race weight for a '70. My '65 had a race weight of 3758 lb with a TH400.