Beach Bum, glad to see you haven't given up on the CForum:cheers:!
Good info on the SR P&P job, I think you might see a half a tenth MPH improvement with the Plenum holes hogged out, and port matched and with good radiuses.

Ski_down_it & Ralph: WOW you guy’s got brave on the runner/base ports, your gaskets are hanging by their fingernails! I did a very mild port job on all three pieces, and then polished the runners and base. I just measured my base’s runner openings, their 1-11/16s inches.

It’s kind of funny, you guy’s went max on the runner port size and left the Plenum alone. While I when the other way, my box has four large ovals (3-7/8” X 2-1/16), with radiuses going to about 1/8” away from the outboard runner screws. The tops of my runners are matched to the box. My theory is: the hell with the little bridge piece, it just contributes to the already low RPM ceiling of the SR design. Plus, I’m a big fan of the big to small induction path philosophy for street engines (velocity, Yhada-Yhada!).

:cussSpeaking of SR~Accel casting flash/anomalies, Holy Sh** I think Henry Ford and crew probably did cleaner cast mold parts on the Model-T:cuss ! And the fasteners probably lined up better too:banghead:!
I’d post pics, but I don’t have the patients right now.

:crazy:NanoBrain:crazy:

 

Nano, my plenum is completely polished and cut open as well. In fact, i tried siamesing the runners such that i could put my hand into the base thru the runners. btw kids, dont try that at home...i lost power everywhere.

Ski, i think you might be overestimating the results of the header test. The weather correction you were using seemed high to me based on what i know about my car. I think the difference is more like 6-7 hp.

An observation on porting the intake: From what i've seen, it doesn't make that much of a difference. One would expect it to make a fairly large differnce given the length/size of the runners and how poorly they are finished and how badly misaligned they are. However Bob Sebrowski and i have the exact same setup, only my intake is ported and his is out of the box. We run almost identically....side by side, same track, same weather. I have a bit more mph and he short slightly better....but the differences are tiny. Corky's car should have clearly benefitted from the ported intake, but he is still looking for the additional power. Beach, it seems that you are seeing some benefit, but without accurate weather comparisons and same track conditions, it's hard to quantify. I've spent countless hours working on this intake as it was a mess and looked like HP waiting to happen, but i dont think it has made as big a difference as i had hoped.

one more point: the AFRs are advertised to flow about 260cfm. A stock SR (runners and base) is good for about 230-240. Porting it can bring that up to about 260. Beyond that and the heads become the bottle neck (assuming they actually flow 260 to begin with).

And my last observation: Contrary to popular belief, superrams work well with big cams, particularly when installed on big cube engines.

 

I didnt want to port my own so I got on the internet and met a nice friend who sold me the TPIS big tube runners and Ported and cleaned TPIS plenium that is now NLA..All in Black powder..

Getting these from a good source is key..

Rob

 

I am probably going to run the slicks on the dyno? Good idea? :cheers:

I probably will just run the converter unlocked. :cheers:

 

Ralph,

I said about .07 sec would that correspond with your 7hp? You would know better than I would, as your track experience is much more in depth than mine and dealing with weather conditions etc. Hell I am still learning how to not overshift 2nd gear :lol: :jester

How many .xx sec is 5hp worth? And does the relationship stay linear you think, for say 10hp gain. You and Beach would know if anyone does.

Anyways I would have to agree that Corky and My engines would have to benefit from the SR, but I think the heads are the bottleneck now, as I explained earlier. But someone else is going to have to be the guini-pig for that experiement, or I will save it for when I want to be single again :jester

I still need to do that trick with the vaccuum guage to see if I am pulling a vacuum in the plenum. The dyno I just thought would be the best time to test such a theory out, right?

Here is another thought? Don't laugh at me either, thinking outloud. On the dyno of course, and I can't believe I am going to say this..LOL.
If I were getting a restriction, ie pulling a vacuum in the plenum. Could I unhook my MAF and tubing etc and just run into the plenum with the TB? I would could leave the MAF hooked to the wiring, or do you think it would set a code and run into limp mode. I could disable the MAF diagnostics in the tune real easy. Since at WOT the car just runs a given set of parameter for fuel, AKA open loop. I know it would run like a turd up to actual WOT. Just a thought. Anyone ever hear of trying that? Or have I totally fallen off my rocker. :D

I think if anything is a restriction its going to be the TB itself, isn't that what that other guy running 10s found?

 

Ralph,

I think the porting is definitely helping me, and not just from the traps I ran this past weekend, I have seen the same results on the 1/8th and even at the high elevation LACR, I was running fast.

The temperature last Sunday was between 75-80 degrees all day, 29.92 barometer. With the exhaust corked up and front Fatties, it ran 117.5 and 117.1 on successive passes, the 2nd one the motor was at 200 degrees at the starting line, the first at 180.

The only time the car has run up in the mid 117's in the past was with 60 degree weather, 30.00+ barometer and the front skinnies on or a lightweight driver with my set-up, so far I think its a solid 1 mph gain. The only change made is the ported Superram. I think this week, I am going to pull the plenum off and finish porting it and see what happens at the track this Sunday.

Ski, Not sure of the benefit of porting those plenum webs out, I will simply be opening up the plenum to match the runner entrance and do a gentle blend into the runner.

Regarding the bottleneck, always a tough one... you and Corky may have found the MAF airflow limit.... we knew it was up there somewhere, just didn't know where. An old rule on when the heads become the bottleneck is intake airflow times two.... 260 cfm should be good for up to 520 flywheel HP with everything working perfectly. But dunno how accurate that old rule is, a lot of variables as you know. But, I'd bet a nickel if you guys got your head flow up to 290 or so, you'd be in the 10's.....

One other note, 123 mph is enough to be in the 10's, though just by a tenth or so, but if I recall you're still running 60's in the 1.5's.....that type of HP can pull 60's within the mid to high 1.4's, maybe by going to the solid roller, your motor wants a bit more stall....I don't know, but I'd work on those 60's.

Beach

 

You have to be making SERIOUS power to blow the tires away on the rollers unless the operators do not have you strapped down properly.[/QUOTE]

Or you got POS bald tires or something...

Love this thread! :lurk:

 

SKi, I think if you were able to trick the ECM into thinking the MAF was maxed during the pull, you could pull it out of the intake track. Otherwise i think the ECM would get confused.

Beach, i hope you're right about the porting. In theory, i would definitely agree it SHOULD help. Just not seeing huge gains from it. If you think you've factored in all the variables and still believe you've picked up HP, then you're an example of theory matching reality. I suppose i could make the same claim as i usually run better mph than Bob, but he's usually a little quicker to the 60 ft. .....however the differences are minimal and on any given day either one of us could be the quicker car.

 

I guess what this is telling up all, since we all have mixed setups with the SR being the on all the car and also AFR 190 heads, I believe are topping off all out engines is they are the bottleneck.

Anyone want to loan me a set of 210 heads for trial purposes? :D

That is what its starting to look like to me. Have any of you guys touched your heads from AFR. Mine aren't even the competition port, just out of the box with the valve and spring upgrade. The springs were obviously replaced when the solid cam went in.

I would like to lay everyones setups out and compare. I think we may have a winner with the 190 runners though, as ralph said they flow X amount in advertisments, but do they really.

I fear that with the bigger heads you would loose velocity though, unless the volume of air being demanded would pick up the slack and keep the velocity up.

Could this all have something to do also with why the thirdgen guy are adiment about telling me I am out of injector, at 4200....I called :bs to their formulas they were throwing out like the wind and said until someone can prove that I am without a doubt out, then I would have to say the formulas are wrong. Or my engine is just really efficient.

Sorry to throw another topic out, but maybe its all related. :confused:

 

Ralph - It looks like the ported vs stock superram on a 350 doesn't make much of a difference as compared to Beach's 383.

Speaking to Bob and yourself for the last 2 years, it seems that you guys have a couple of slight differences, like gearing, convertor and ported/unported superram.

Vic

 

My friend's IROC back in '92 made 437/492 and it was the identical combination I have in my vette(LPE did the car, it now has an 18* head 434). LPE-383 with d ports and a fully hogged SR with matching heads. The car was never "officially" raced, but did clock similar speeds to mine in a heavier car. That's it in the sig pic. It dusted off a nitrous equipped 11 second s-10 truck like it we're a VW yesterday on the way back from a show! :lol: :steering:

 

Ralph,

I think Superram porting can potentially be as much as 15-20 hp, I think LPE advertised 20-25 hp, I didn't see that much, but then again, still need to do some plenum work yet. Don't know why you didn't see a gain.... gotta be the 350 cubes or ??

Ski,

I think big heads won't kill low end torque as much as previously thought with a SR and big cubes. I wouldn't hesitate to slap on some 220-225 intake runner heads, in addition, any low end torque lost wouldn't bother me as long as its traded for higher rpm HP. I would simply run a few more hundred rpm of stall to maintain the 60's.

I agree with on the injectors, I was told several years ago on this forum my 24lb injectors wouldn't be able to sustain my low compression 383, and you guys are running the same injectors on a solid roller 406's that are threatening the 10's. I think my fuel pressure is set at 42 right now.

JD,

I'm trying to figure out your post... but did you install a 18 degree head 434 ? If yes... Wow!!! That outa be fun !! Also, Why ? 383 okay ? What happened to the 383 if you did ? What manifold are you running with those heads ?

cheers,
Beach Bum


[Modified by Beach Bum, 7:56 PM 5/20/2003]

 

Beach like I said I will have to have a donor set of head given to me or I will be single :jester :D

Corky and I just got off the phone and we have a few tricks still up our sleeves that we are going to try at the next strip we go to to assist in air delivery. I am going to try Ralphs suggestion of a vaccum gage on the car hopefully to see if I am pulling a vacuum.

I can't ever remember this so I am going to ask. IF I unplug the FP guage line, during a WOT run it shouldn't matter right, since there shouldn't be a vacuum at WOT anyways. It will just run richer at Part throttle. Or should I leave it attached. I have very little time to get stuff ready for tomorrow and really would like to try that out with the vac gage. That spot would be an easy spot to attach the gage, what do you all think...

Good discussion anyways.....We are cutting such straws at this point its sorta funny. 10hp when your making 350+RWHP is pretty hard to see and proving its there is even harder, especially with track variables added in. The dyno is really the only place you have some unarguable data.

Later I am tired!

JD I think meant his friend had that setup. :flag