StealthFormula

iTrader: (35)

After reading how ported '93 LT1 intake manifolds have the potential to outperform later year LT1 manifolds I decided to wanted to give it a try because I had nothing to lose except for a few bucks and a little bit of my time. I previously ran a ported '94-'95 intake manifold on my stock bottom end heads/cam car. The port work done to my old manifold included enlarged runners, obstructions removed from TB area and TB holes opened to 58MM TB. The work appeared to be of great quality, was done by a reputable LT1 porter and I never had any complaints with it whatsoever. I simply wanted to see if I could gain a little ET or MPH with my particualr setup.

I got in contact with Josh (STOCKTA) who ports various things with LT1 manifolds being one of them. After discussing options we decided to ditch the '93 intake idea because I didn't want to deal with the fuel rail crossover differences so we decided to run another '94-'95 intake and do some "extra" work to it above and beyond the typical port work done. This extra work including using epoxy, the purpose of the epoxy is that it allows you perform more port work to the manifold that you would not regularly be able to do because it eliminates vacuum leaks that would be present without its use. Josh had confidence that this "extra" work would allow the manifold to outperform my current ported stocker so when I installed the new manifold there was only one way to find out. I went ahead and made several passes at Maple Grove Raceway both pre and post swap and the results are below.

Ported Stock Manifold:
Avg. 60' = 1.58
Avg. ET = 11.530
Avg. MPH = 118.10
Avg. DA = +602

Ported and Epoxy'd Stock Manifold:
Avg. 60' = 1.61 (-.03)
Avg. ET = 11.561 (-.031)
Avg. MPH = 118.02 (-.08)
Avg. DA = +1745 (+1143)

When corrected to 0 DA for a fair comparison (identical correction factors used), the true results are revealed:
Ported Stock Manifold Avg. = 11.47 at 118.65 MPH
Ported and Epoxy'd Stock Manifold Avg. = 11.33 at 120.44 MPH (+.14 ET) (+1.79 MPH)

I'm no Scientist and it can be argued that the results could possible be slightly skewed considering the manifolds were ported by two different reputable individuals etc. etc. but I tried my best to keep as many variables constant as possible. Everytime I make a pass I log various things so I was able to keep constant several variables including tire pressures, shock settings, launch rpm, tires used, track used, amount of gas in tank etc. Bottom line is that these are real world results and the ported and epoxy'd stock manifold infact outperformed my ported stock manifold on my basic stock bottom end heads/cam car. The purpose of the thread is to share my results and introduce that having additonal epoxy work done by a professional has the potential to be a good bang for the buck mod for the person seeking that extra tenth or MPH out of their heads/cam or stroker setup. It is also to reiterate the fact that it is fair to assume that even a basic ported stock manifold is a good bang for the buck mod on a heads/cam car.

The results were better than I expected so I have to give a big thanks to Josh and his Father for doing one hell of a fine job! Hopefully Josh will chime in to explain exactly what was done to the manifold for anyone that is curious.

STOCKTA

iTrader: (8)

Once I dig up the pictures of your intake manifold under construction I will post them for all to see as I refuse to hide any secrets

I appreciate the kind words and great results you have to share with us.
Im shocked that it picked up over a current ported intake and very happy this turned into a gain to bring you closer to 10's. Im sure we both speculated the gains in doing the extra work and epoxy tricks over a proven intake combo you were currently running.
Thanks again!!!

speed_demon24

iTrader: (6)

I'm not a fan of correcting 1/4 e.t. since the results were so skewed when I did it to my own before. But it's nice to see some actual real world results on the subject instead of bench racing. Makes me wonder how much if any my stock manifold is holding me back.

StealthFormula

iTrader: (35)

I've had luck with it but yes your are correct it can be potentially skew results. With the 0 DA correcting aside we can still see an almost identical ET and MPH in an additional +1100 DA which shows a gain. How much of a gain exactly? no one will ever know but I'm willing to bet that a tenth in ET is a fair assumption. I would venture that it is holding you back a bit, nothing crazy by any means but enough to make it worth your while to swap to a ported.

STOCKTA

iTrader: (8)

This intake started out as a 94+ Iron head Impala intake or could have been a 96+ F-body intake as they most typically are casted as a more square intake port and better internal angle behind injector holes.

My father and I test fit a spare fuel rail and injector setup to see how much meat we could add on to outside of port roof. Where the fuelrail hardline cross over is casted in we guaged the distance between hardline and intake casting. This was to allow us to build up casting meat under hardline as we just about ported out the hump that you can see on plenum roof while looking into TB holes without breaking through.

This picture show the Belzona super metal epoxy we used on this casting and the acid used to clean pours out for better bonding. Also note the outside was hit with the carbide bit to clean up aluminum before applying metal epoxy.



This next photo show the epoxy after applying it to stock casting, look close at top fuel rail cross over to see where we used epoxy to meat up that area. Meat lol Meat



This picture represents the potential amount of material that can be takin out of the port roof to straighten the path of air.



As you can see the L-shape felt when running finger down port roof throat is removed and you can see where it breaks into the epoxy.
The scratchall tip is pointing to area that gets thin when trying to get every thousands of an inch gain on porting the roof straight. I feel this is where StealthFormula gained the most from as the air has a much more straight shot to cylinder head.



This shows the ruffed out port next to a stock port to see how much can be takin out when using an epoxy or welding the outer wall.


This is a picture of his internal fuel rail crossover to see how much we actually cut on that, I swear there is two hours just porting that damn bump down lol.


Look close in picture and see if you can find the prototype stuffer we are creating hehehe.

We also tested a plenum stuffer that would go behind TB holes on roof of plenum. This was a prototype that did not last long under some stress testing we performed in the old oven at 300-400 degree's I feel if we made these in aluminum that it would definitly help air path coming directly out of throttle body opening.


If you guys have been here long you will remember when Jordan Musser used to show off his port jobs and how he actually welded this area that I epoxy. From testing on my own personal intake at least 5-6 years ago I have felt the Belzona does just as good as a weld for holding up.

Puck

iTrader: (17)

You do some very nice work.

There are def gains to be had with epoxying, but it is a LOT of labor. Whether or not its worth it depends on the car owners goals, how much they are being charged, and who is doing the work.

Just like stock casting heads, there are fundamental flaws in the castings that porting alone cannot fix.

mean_greenZ

iTrader: (1)

I'm not following the epoxy concept..what does it have to do with porting? I would like to learn.

STOCKTA

iTrader: (8)

Really not hard work to epoxy just time consuming and this stuff is like cement when it sets up hard, and a pain in the *** to apply smooth. After it sets up dad and I sanded down the epoxy to make it smooth and hidden under paint job.

STOCKTA

iTrader: (8)

The epoxy on the outside allows the casting to be thicker where I would normally break through the casting with porting causing a vacum leak.

Look at this picture where the scratchall tip is pointing, you can see where its broke through the casting to get it where we want it, hence the epoxy.

robsquikz28

iTrader: (246)

bad ***, lots of labor in that badboy I can truly imagine. How much does this cost someone, pm me b4 the tech police hound this page.

StealthFormula

iTrader: (35)

PM sent

Yeah not trying to bend any sponsor rules just trying to share my results and show the LT1 community something they can consider doing when they are seeking for something that will give them that extra tenth out of their heads/cam or stroker setups.

Rob94hawk

iTrader: (1)

I remember STOCKTA's intake manifold for sale that I was interested on cz28.com but just missed out by a few hours! Nice piece of work too!

http://www.camaroz28.com/forums/showthread.php?t=760362

Travis Johnson

iTrader: (2)

Averages are nice, but they don't tell much without knowing the standard deviations. On average it can look like an improvement, but if there is a high deviation that might not be the case.

And then you can do a hypothesis test to know if there is a significant different or just chance.

And I've taken too many statistics classes.

mean_greenZ

iTrader: (1)

Ok I see now. Thanks!

StealthFormula

iTrader: (35)

Yes lol. I took a stat class a couple years ago and the standard deviations are low, for example all of the runs post swap are within a few hundreths of a second, the car is consistent.

If you put a cam in a car you don't perform calculations and get all statistical, you go to the track and make some passes to see what you gained. Same here, I went to the track and made some passes, swapped the manifold and made some more passes while attempting to keep as much as I can controlled. I then have my results and it is impossible to know exactly what the true gain is but we have a clear gain when a car runs within damn near the same ET and MPH just in +1100 worse DA. This is no scientific experiment, just having fun.

Travis Johnson

iTrader: (2)

Alright, as long as the deviations are that low it should be a real improvement.

Just looking at the numbers and how close they are, there could easily be no appreciable difference if there were larger deviations.

StealthFormula

iTrader: (35)

Absolutely, if we had an 11.70 run, a 11.50 run and a 11.30 run and come up with an 11.50 avg. that wouldn't mean much at all because the deviation is huge. Luckily that's not the case here otherwise we would never know if was worth anything or not.