L-75 455 TA FAST BUILD #2

[1qikta]

Hey guys,

Looks like a great section that I hoped would show up. I am sure Mark had a lot to do with it.

As a few of you know I run in the FAST (Factory Appearing Stock Tire)series,mainly due to the L-75 455 I run and its low 250 hp rating. I would get eaten alive in the Factory Stock Class so FAST seemed a good fit with its open rules on internal engine mods. Over the last 3 years I have really maxed out my 4x heads flow and other key areas of my setup until the well just ran dry at a 13.01 @111.06 in Cecil Co. Maryland. Feeling this is all I am going to get out of this particular combo I consulted a few Pontiac guys and started on a new L-75 project last August.

My goal for the L-75 project is 600 hp and 650 ft lbs tq... and on the track a high 11 at 117plus mph. If I could do this it would put a first ever D port Pontiac into the FAST 11 second club and more importantly have me solidly into every field. Keep in mind all factory pieces have to be in place i.e. Log Manifolds,EGR system,AC,Iron Intake,Quadrajet and 70 series tires.This has never been an easy thing and I think that is why I enjoy it.

In the next month all the pieces will be in place to finish this up and this section would be a great place to post my progress. Due to the rules and what I have to follow it has not been cheap, but it will be fun to see how far someone can take an L-75 455 on the dyno and at the track!

   Jay

[1qikta]

 Back in January I was able to ship off the New Transmission as well as the new correct dated block and heads. There was no way the projected torque numbers would work with my Super T-10, I saw no other option than to go with my original trans...a '74 Turbo 400. Also reaction times, sixty foot times and consistency would be gained.

At this point a custom crank was ordered from Moldex...little did I know it would take 7 mos to be delivered.




Correct date coded Turbo 400

[1qikta]

 The '74 Trans Am loaded has to be one of the heaviest muscle cars out there.My race weight has been as high as 4150 lbs.To meet my goal taking inconspicuious weight out of the car is key. To date I have found 350 lbs that simply cannot be seen...and most is completely replaceable. At the next FAST race in October I am looking for a race weight in the 3780 range. Later in this thread I will go over some of the places you can find Jenny Craig. Keep in mind 100 lbs = a tenth at the track.

[Formula88]

[Father&Son7379T/A]

Jay,good to see you found this thread,I actually started the L-75 thread.
I've always admired what you did with your L-75 and the article in HPP,I've also seen your car at the 07 NAT's.
Impressive to say the least.
I dream to do what you did,I will some day when the original 455 in the 73 needs rebuilding,I'm not spending money on a rebuild to get back the same horsepower,I want that total factory correct numbers sleeper thing
I almost did it when I sold my 68 442,but then I split the 79 W72 with my dad.
I'll just have to wait.
You used Central Virginia repair or something?,I spoke to them after the HPP article and talking to you.
Amazing what can be done to an L-75 using original parts...........

[1qikta]

 Thanks Father&Son.

You are right, Jim Lehart at Central Virginia Machine has been my guy for a long time.He has an open mind and is not afraid to try things unusual. His business is just the right size to give the personal attention these builds need.

 My first effort with Jim at a FAST motor maxed out at 450 hp and 550 tq. Many changes with that motor thru different cams and head/ intake flow told us a lot about what we could do and things that just didnt work. The obvious changes left to improve on with the new motor were compression and cubic inches. Taking the motor from 465 cubic inches to 501 and increasing the compression from 10.3 to 1 to 13.2 to 1 looked to be the quickest way to make more power and torque. Both I understand though to be the limit and maybe beyond dependabilty.No one that I am aware of has tried this combination.The rules though have me out on a limb.

Block- Block will get Program Engineering 4 bolt caps,o ringing,hard fill to the freeze plugs.Align Boring, Cylinders cut 0.60. Also the necessary clearancing for the custom crank.

Crank- Moldex custom Billet  3 1/4" Main with a .990 pin. 4.50 stroke,knife edged and bull nosed.

Bearings- Will all receive a thermal barrier coating

Rods- Eagle BBC 6.800 length

Pistons- Ross Custom with 15 cc dome ( hand cut flame path),Thermal barrier coating

Head Flow- Previously my old heads maxed out at 278 cfm @ 600 lift. Which most guys will tell you is the limit. Jim and LD (Jim's porting Pro) have somehow moved my new heads into the 290's  . One of my new completed 4x heads was actually on display at the Pontiacs in the park CVMS tent. I thought that was pretty cool.


Cam- Comp cams custom hydraulic roller grind 242/248 @ 0.50   554 560 lift   114 LSA

Lifters- Comp Solid roller lifters

Intake- The new intake will be similar to the old one accept the center divider will be intact for additional torque.The same cross sectioning treatment and RAIV port matching will be in place. Approx 5 bs of material will be removed from the intake leaving it almost paper thin.

Carb- Will be a Cliffs Q-jet massaged to 840 cfm..Plenty for the application

Manifolds- They will be my old faithful Logs that I have maxed out thru port matching,Hand Porting and Extrude honing.

Ignition- Stock GM dist with a Crane Xr-I conversion.

[1qikta]

 To free up the most friction possible I decided on the Comp Billet timing set and the Harland sharp roller rocker. To compliment those components the sims roller thrust plate was used freeing up as much as 15 hp on the dyno.

[Larry Navarro]

I'm feasting on this stuff Jay. Glad you have taken the time to showcase the build.

[1qikta]

 Thanks Larry..Jump in anytime,

 Reciprocating weight- One of the big differences this time around for me is weight..in particular the round and round kind. Starting at the front....in order. Keeping the internal bob weight down, As small of a stall converter as possible(10"), An Aluminum driveshaft, A full spool, Gun drilled axles, Aluminum brake drums and lastly the lightest stock Pontiac(TA) wheel...The Rally II. The last item ..the Tire, I will go over in a later post.

This saved 148 lbs of rotating mass


Continental  10" 3800 loose converter


Custom aluminum driveshaft 1350 yoke and u joints


Auburn 33 spline full spool


Moser 33 spline axles with gun drilled and C clip Elim option


1985-87 GN Aluminum brake drum


Pontiac rally II wheel

[Formula88]

Wow - 148 lbs of rotating mass - that's a HUGE improvement!! 

[1qikta]

 Nose weight- Transfer of weight and getting the nose of the car up is huge with traction. I have wrestled with 60's since I have been running the TA. Here are some of the front end weighty items I have found to remove or partially remove.

 Battery- Hollowing out an old Delco side post battery case and rigging up a Dynabatt battery inside saved as much as 22lbs out over the driver nose of the car.

 Front Sway Bar- I removed it completely..stored in the basement

 Main Bumper brace- The brace that runs the length of the front bumper ..40 lbs worth is not all needed.With help from my buddy TA Junkman I found another brace and cut out the non mounting area and saved approx 35lbs off the center of the nose.Original brace saved in basement

 Connecting brace. Just behind the license tag of the car lies a supporting brace that weighs 13lbs and is like unbolting a concrete block.Saved in Basement

 Horns- The horns out front are removed and good for an additional 5 lbs. Basement...

 Springs/Shocks- The addition of drag springs and shocks really helps the transfer..I just painted both to look stock. Recenty with good traction I can feel the front end hitting the shortened bump stops so hard it feels like the left front tire is hopping off the ground during my 1-2 shift.
http://www.youtube.com/watch?v=jq2YSqBJLBg

[78TransAm]

Jay, thanks for the updates and info....I find all this informative and useful.

[critter]

Jay, you know those old 74 TAs are pigs. Why don't you give up? 

Great stuff you're sharing here. I can't thank you enough. You've got me thinking again..

Who did your drive shaft?

[Rodent]

Jay,thanks for taking the time to share.Keep it up.

[1qikta]

Who did your drive shaft?

Chris,

  Driveshaft service here in Kennesaw,Ga did my driveshaft. It was about $450.00. Spicer parts.

  Interior sprung weight,

 Since I must keep the appearance of my window stickered options I had to be creative with my illusion.

   The weighty option I have are:

   Air Conditioning
   Rear Defrost
   AM/FM Radio
   Rear Speaker
   Stereo 8 track
   Power Windows
   Custom trim group i.e. Floor Mats,deluxe bucket seats

                                                            Treatments

Air conditioning
My A/C is not charged so I run no pressure in the system.Fan Motor removed(3 lbs)..Stay tuned here.

Rear Defrost
The motor is removed saving 3 lbs. I spray painted flat black a piece of traced cardboard..it backs my grille to where you cannot see into the trunk and it does not draw the eye.

 AM/FM Radio
 The radio is removed only exposing the dials and facia...-7 lbs (See 8 track)..In Basement

 Rear Speakers
 Both are removed..the one grille has the defrost styled backing.- 6 lbs In Basement

  Stereo 8 track
 The player is removed and bagged in the basement. Some cardboard,vacuum hoses,duct tape and chop sticks do the rest.-11 lbs In Basement

 Power Windows
 I am considering removing my pass side motor.. stay tuned.-6 lbs

 Deluxe bucket seats
I bought a set of front and rear white deluxe seats to see how much weight I could gut. The reality was that the passenger seat yeilded the most.Messing with the driver seat did not look too safe. The rears were more wire than anything. Anyhow, the pass seat was stripped to the frame and 7 lbs of steel was plasma cut out and any un-obvious foam went away as well.Just died it to match the rest of my interior.Original seat in basement. I ended up selling the driver and rear seat from the purchase.

 Stock original rubber mats
I just pulled them out.Not a big eye draw.. Weighing in as a set (9 lbs) it was an easy choice.


Stereo 8 track


Back side