I love it. I think it is the right way...the only way to put a bell mouth on a runner who's wall is so thin, there is no margin on which to grind a bell mouth shape.

 

BHR, I settled on this as my solution for the throttle linkage clearance. Worked on it last night for a little bit....I'd have driven it to work today if not for the fuel-leaking Perf Prod's auto-leaking FPR.

 

Side bar question: You guys see those injector clip boots? Where does one find new, not-cracked boots?

 

No intel on the boots?

Finally got a minute to work on the Prof Prod's FPR and got it to stop leaking. Directions say it's set at 40 PSI, "Typical for most EFI systems". It was set at ~65 PSI.

Fixed leaks, lowered pressure down to ~45 no vacuum, fired it up. Sounded good and I took it out for a blast and to get some gas in it, It ran fantastic, no issues. I'll drive it to work tomorrow and if all goes well (which it should), I'll make another, possibly the last, appointment in the 10x the tork, take too, test. I can't believe it's the end of August and I'm only now, getting to the second test of the summer! How lame. At least it's getting done, I guess. I'll update when I have more to share....

 

Mike1111, thought you might get a kick out of this vid I found from the old days. L83 vs. LT1.
In the far lane is CFI-EFI in his '84 L83/auto. Mods were; massively ported CFI intake, true dual 2.5" w/no cats, and a converter.
In the close lane is a guy that used to post on various forums under the screen name "Warship". His car is a '93 LT1/auto, LT headers, CAI, 1.6 rockers, gears and a tune, IIRC.


14.77 to a 14.78.....Now THAT was a race to the finish!!

 

cool. a hole shoot. I like crossfire. that manifold must have had thin walls. fun winning with a perceived underdog car.
I did a little porting to a different intake.
ported runner #8 on intake manifold. # 8 was the weakest runner on previous intake. 1.5x1.1 got 239cfm top off. 229 with top on. With stock top with no whirl plates. swirl plates start to restrict at 200cfm.
still have room to make runners bigger. theoretically 1.53x1.13 would get 250cfm with no top and 239cfm with top on. thin wall would be 1.56x1.16 would be 260cfm without top and 250 with top. have to see about all of that.
top radius does affect the flow. Going to build part and weld it on. forgot to take pictures.
need a quicker cutting burr now that I know how to do this.
have to port #6 runner next, if it flows like #8, then should be able to get good flow from all the runners. outer runners are harder to get to flow.
If this works out and I can port all runners to 1.53x 1.13 and get 239cfm with top on. this would be a good intake for crossfire. I'm not comfortable with super thin walls that 1.56 x1.16 or 1.59 x 1.2 would have. have to sonic test to see how far I'm willing to go
stock intake flows 153cfm with top on. ported intake flowing 239cfm with top on would be great for me. still having a hard time believing this worked.
does anyone know where to get a good fast cutting burr?

 

Nothing is more rewarding than winning w/an underdog. I used to love opening my hood at RMR (our drag track) and blowing folk's minds with what appeared to be a 305 CFI w/headers.

Jim's intake was ported until the walls/ceilings and floors were paper thin....and even until they weren't there anymore! After he was done porting, he brought it over and I helped him epoxy all the places where he "windowed" it, or ground clear through. After the epoxy cured, he hand sanded the epoxied places to thin and smooth them to match the bordering areas. I don't think that a CFI intake could be ported any further than his was...and I wish that he/we'd known about your discovery of the bell mouth entry. His runner entries were razor sharp which I know, hurt flow. I knew back then...and I'm sure that he did too, that a sharp entrance isn't good for flow, but w/zero material at the mouth, there was "no way" to make a bell mouth. We didn't think about adding material around the mouth, like you (and SuperL98) have done. Oh well.

Note that in the drag race above, that is in SLC @ 4500' elevation....I never saw a DA there, below 6000'. Hence the pitiful (but normal-for-that-track) numbers for the LT1. Both cars would be LOW 14's/mid 90's at sea level....and that's pretty great for a ported intake/exhaust/converter L83.

 

I learned a lot from SuperL98 post. smart guy. after all that trial-and-error, welding and testing. I stumbled across the fact that a larger CSA entrance flowed more efficient than a razor edged maxed out port. Can't radius all 4 sides on crossfire. Where material can be added for radius, it ended up looking like a bell mouth. Working HVAC, seen a lot of bell mouths. looked up how they work.
Sheetmetal test port showed a 20cfm gain from adding 2x1.125 entrance with 1.53x1.125 main runner vs straight runner. that thin-walled intake must have still flowed 260+cfm. must have gotten into water jacket. Fun. Pacific raceways Kent, WA. is the closest track for me, 308' elevation. seems like NHRA set a new record every year.

 

I'd guess that the head/cam was capping the power similar to in my situation testing these intakes. He did hit water in several places. That was no big deal w/the epoxy...that sealed it up good and never leaked. I thought the water jacket under the runners was dumb, so I chopped mine out...used epoxy to seal both ends up and never had a leak with that, either.

 

I have looked at cutting the water jacket off the bottom and welding up the ends. would want to make a jig to hold intakes shape while weld. stop the warping. that would be a wild intake

 

What did you do I cant tell? I bend that part of the linkage out toward the fender to clear the holley rails I also run the fuel lined right there making it even more tight going from the back like you did is better but on F body the fuel lines run along the driver side down almost to the headlights dont feel like changing that much dont think its much of a issue using the 85-88 TB, also I use the TBI waterneck for SBC

https://www.ebay.com/itm/126176204733

 

Fuel comes in on the pass side, rear. X-over is in the middle, exit into the FPR (not pictured) is on the driver's side rear...return drops out the bottom of the FPR.

Here is a better pic, that includes the FPR....

 

Laaaaaaast dyno session (for this engine), today! Went back to Adrenaline, and put 'er on the rollers for a spin w/the HSR. How'd she do?

 

Do we have a new HP king ooooorrrrr ?

 

That's it!? Where's BHR! He's kicked azz w/the guesses!.....

 

He's been posting on FB quite a bit

 

265 350

 

Nice! GOOD prediction. Any others? Last one! Last chance to "HP Gamble"!

 

I'm in. 277 HP 363 TQ

 

275hp.

 

I'll go 10-15 hp more and about 10-15 less for tq than top dog so far. I think heads and cam are keeping things down close to same.

 

SR 288 374
Siamesed ASM 280 375
Prototype 275 373
Tram 276 356
Mini ram 258 321
stock 241 342

You saying Stealthram 298-303 HP and 365-360tq? I'm actually thinking of lowering my prediction

 

That's my very optimistic high end. Reviewing the mini ram number's has me 2nd guessing. The stock heads and cam are really killing the short runners but maybe the stealth found a sweet spot.

 

Yes the mini ram is throwing me off as well could be the tune that was hurting it, but then the t ram also isnt matching the TQ either and that has longer and larger runners then the stealth

 

Weeeeeeeelllll ??

 

Yeah, yeah yeah.... I've been procrastinating.

Unfortunately, I don't have the graph for that intake! I'll have to email Adrenaline and see if I can get it. IDK how I got out of there w/out it. Anyway....(Drum roll)....

273 RWHP @4970 RPM and 343 RWTQ @ 3600 RPM.
Being a short(er) length runner intake, it was more like the Mini Ram than the others. But still, the HSR blew the Mini Ram away in these noteworthy areas: It did a very solid, 32 hp gain over the stock intake....R&R only. I paid $300 for this intake and $100 for the rails/regulator. 32 hp for $400 bucks is some pretty fantastic bang for the buck. The Tq basically matched the stock intake, peak for peak and was 20 over the Mini Ram, and it was making ~310 ft lbs at only 1200 RPM. That is substantially more "low end torque" than the stock TPI intake, and the Mini Ram.....and pretty competitive with the other LTR intakes, below 2000 RPM. The HSR also carried power out about as well as the Mini Ram, peaking just about 5000 RPM (same peak RPM as the Mini Ram), and still making about the same power at 5500 as the Mini Ram did at it's 5000 RPM peak. This intake was a huge improvement over stock and a big improvement over the Mini Ram, for about the same money and effort. Ultimately, this is an affordable, easy to install intake that did pretty good on a stock engine, and we know that it shines as we improve H/C/I/E, so it's pretty high value. Even though it was the "second worst" aftermarket intake, it was really close to the T-Ram (2-3 hp down), the Prototype intake (basically a "Bigmouth"), and even the AS&M it was 7 hp down on....not a lot.

So there it is, folks. I'll see if I can get the graph and post it.

 

That's pretty wild.

Next round of tests is with the same intakes, but a 190-195 head. Lol

 

Yep....that'd be cool...but it will have to be someone else doing those test$.

First, it's a pretty big commitment, time wise and money wise. I'm in it over $2k and it's been fun, but I'm good.

Second, as I left the Adrenaline Dyno after doing the HSR pulls....this started.....

 

So....

That dog is dead.

 

The squeaky knock of death. We should set up a go fund me for your efforts in this endeavor!
if i can help somehow, let me know

And thank you so much for doing this, it is great data for all to use and see

 

This is a historic thread.

 

what throttle body size did you use for the stealth ram and the mini ram, did you notice lean issues with the stealthram like you did with the mini

 

Stock 48mm TB on both the Stealth and the MR. I tried a 52mm Perf Prod's on the Mini and it made a vacuum leak and ran like ****.

The HSR was super lean like the MR on the first pull, it was ~16:1. I bumped fuel pressure and got it down to ~14:1 while on the dyno.

 

Shame to hear that on your motor. She definitely put in some dyno work to make this thread happen!

 

Thanks, but I don't feel bad about it at all. I've known the engine was a short-lived turd since I bought the car in '17. Valley full of sludge, valve covers full of sludge, burned oil and made a healthy plume of blue smoke.....none of that looked like an engine that was taken care of and was long for the world. Because of that, since the Kart became road worthy, my goal for the engine was to tool the wee out of it, have a blast with it, until it blew. Goal accomplished. Dyno data was a bonus.

Got the HRS Data from Adrenaline...and I have to say, Jared at Adrenaline has been a bad azz. Great guy, fun to car-guy talk to, he got into it with this testing...even though his bread and butter is tuning exotics, he made the time to help me do all of these sessions and pulls. Guy is totally awesome. Anyway, props to Jared and Adrenaline and here is the graph....

 

Well ****. It's got the TIME on the x axis instead of the RPM! Gosh darn it....

 

Stock

T Ram

Mini Ram

Super ram

ASM Siamesed Runners with Ported plenum and Accel base

GM long tube prototype

Stealthram

 

yes i noticed aswell and the time marks on the graph don't line up to RPM, it would be somewhere in between the lines, hard to interpolate without having more data

 

I'll email Jared again and ask him to send me the version w/the RPM. I'm sure he simply didn't pay attention to that. No one cares about the time. I don't, that for sure.

I'll also ask him for an overlay of ALL the intakes, so we can see 'em all together in one place. Don't look for that until middle of next week. I am starting a new job this coming week so have a lot going on....

 

I didn't want to discourage any testing

But now that your all done

Around when Tom started these tests I opened my stock L98 engine model in Engine Analyzer Pro and cycled through different runner lengths and diameters, leaving everything else fixed.
EA-Pro includes wave and inertia in it's calculations, not just the old fill and empty math, but it does imply a perfect world and we know the world isn't.
The runners are also modeled round, so it uses a round runner with the equivalent area of any rectangular runner.
Should really use the smaller equivalent hydraulic diameter for the rectangular runners.

The very early "Engine Masters" dyno competition used average torque plus average horsepower, over a 2500 to 6500 rpm band, as a way to score the best "Street" engine.
I think that's to high an rpm for the stock L98, so I modeled from 2400 to 6200 rpm

Anyway, if we used average torque plus average horsepower as a scoring system this is what the results would look like.




Easy to see what you don't want to use, but harder to see what you do

With a limited "stock" engine the results all bunch up at the top, much like with Tom's real dyno tests.
If I lower the top rpm even more to a realistic 5800 rpm and zoom in, the results are a little clearer.
A twelve inch long 1.65 inch ID runner just barely tops the pile.




And if we step the maximum down just one more to 5400 rpm, somewhere between 12 and 14 inches long with a 1.60 inch ID moves to the top.




Just interesting data to look over.
Where do these test intakes fall on these charts ... is also interesting?

 

That is interesting....Thanks for posting. Your posts are always loaded with interesting and thought provoking "food".

If I'm reading the Sims correctly, it looks like a 13" runner that is 1.6-1.7" dia would produce the best results. "inch runner", I assume means valve seat to plenum. In that case, wouldn't the HSR be closest to "that intake"?


What I don't "get", and this isn't so much related to this graph, but your statement earlier about the head limits the total power....which that statement made total sense. All the intakes (except for stock) out flow the head by a large margin, so the head "stacks up " the peak powers.

I am not seeing the peak powers "stacked up"; the difference between the best flowing intake in the test, the MR, and the highest hp intake in the test (SR), is 30 hp. That is a huge difference, IMO. -especially on a ~250 horse engine. Also, the T-Ram, which has a similar cross sectional area and very close to the same runner length as the SR, did 276hp/356 tq.....to the SR's 289/375. That too, is not "stacked up" either in tq or power. If I were spending my dollars and choosing an intake, that ~13hp and ~19 tq would definitely sway me. So I don't see that as "stacked up", either.

So....I agree that intakes that outflow the head should make the head dictate the peak #'s , but I don't agree that we saw that here, so clearly as it's stated. What I DON'T "get", is why the 30hp diff? Simply inertia and ram tuning? (Or lack thereof)

 

I've looked at this stuff so many times, I assume people see what I see

Sorry ... should be clearer

The graphs are just the intake runner length.
The total path is the head runner (5 inches) plus the runner length.



Yes it's all about what rpm the boost from the inertia and harmonics lands.
That accounts for the added flow above what you see on the flow bench.




I've said it before, because the MiniRam provides so little usable boost in our rpm range, and no real flow losses, the MiniRam horsepower curve is pretty close to the natural power curve of the stock L98 without any help from boost or restriction from runners, just pumping in and out.
Anything above that line is what the other intakes get from boost or lose from runner losses.




The real world comes into play when we look at the TRam and SuperRam.

Assign a "loss coefficient" to any time the air makes a 90 degree turn in the plenum.
Doesn't matter (for this argument) what that value is.
In the stock TPI plenum, the air makes one 90 degree turn from the throttle to the runner inlets.
In the SuperRam plenum, for most of the runners the air makes one 90 degree turn into the runner inlets, maybe two turns for the two runners around the throttle bracket bump?
The air in the TRam plenum has to turn 90 degrees three times from the throttle to the runner inlets.
I think that's going to hurt flow ... compared to the SuperRam.
Only a flow bench could put a number on it.

The other real world problem with the bigger ID runner intakes you tested is the match up to the small 1204-ish L98 head port.
Bigger intake runners are going to have a nasty shelf at that gasket transition that's going to neck down the CSA there, worse if it's along the top of the runner.
Vena contracta
Might be 10-20 cfm or more, depending on the mismatch.

Also again, what is the "real" CSA of rectangular or D shaped runners, compared to a circular one ... what do I put in the SIM for them?

The real world isn't pretty

 

If the SuperRam has about a 10 inch runner and is maybe two thirds 1.65 inches ID and one third the larger D shape ...

I think there is room for a 12 - 13 inch long, 1.6 - 1.65 ID carefully designed runner to squeak out a win over the SuperRam.

Certainly peak torque, maybe peak horsepower, hopefully the averages

Bone stock L98 only.

Don't know what that might look like, maybe require a new plenum to go with the runners

 

I love that thing you printed.

You're the man who could execute on this one!

 

My test showed a bigger intake manifold port opening to a smaller head port opening is at least 10 cfm. even with a small mismatch. I use bore scope to check. doesn't take much to lower cfm.

 

This is the one I want to finish before I age out








Not good for a stocker L98, but for a top end street 350 or 383+ SBC

3D printing (laser sintering) aluminum is getting more accessible and cheaper every day now.

I want to be ready when it gets just a little more reasonable.

I did manage to get my elbow printed (aluminum) and it's been running in my Vette without issues

 

Somehow, I completely missed post #342. Awesome post. Thanks for the explanation and you must be right. It would be sweet if you could get your hands on the T-Ram and flow it w/the tanks on, and w/o. Smoke it, too.

 

I want to do a t-ram with a t-body on the front of each tank and ditch the weird single t-body airflow through plenum arrangement

 

😮😲

 

Posted in error....How do you delete a post?