Please, don’t hesitate to show the numbers also for the FIRST, because you already started. 😊 Let the haters hate.

 

I don’t think anyone is a hater. I truly believe they’re trying to help. They know what has worked for them and seen the short falls of typical LTR builds.

I tell you what I’ll do. If Miller is amenable, I’ll bump the compression up on that 10xTQ engine to 11:1 for the MiniRam and simulate that along with any cam he wants me to enter for it as long as it’s not any bigger on duration as what was used (236/242) and put what it estimates in the ET simulation. I will say the heads don’t flow as well as AFR195s and it’s going to need more than a 219 cam.

If he’ll do that I’ll post up what the simulations estimates for the 10xTQ engine at 10:1 with a FIRST and a “better” (yes smaller) cam that should pull at least 18” of vacuum and idle relatively smooth around 750-800 rpm.

 

I am running a Weiand Team G and it fits well, just barely clearing the stock C4 hood with elbow. I do know the Victor Jr will not clear the stock hood. While the Weiand may not be the best intake out there, it does work well in my boosted application.

If I built another, it would definitely use the GMPP 13° intakes converted to FI with intake elbow. Those intakes supposedly work very well in boosted applications.

 

Sorry if I was unclear. I meant these people with my comment that you was concerned about:



That would be even more valuable to see the difference between those two intakes and both having proper compression and cam. 👍🏻

 

In that article, the heads are a real problem, I think. They seemed to have choked the engine way down from the power and RPM it should have achieved with the short intakes. Even "as cast" AFR 195 Street heads leave something to be desired. My ported LT4 heads were extremely similar to the AFR Race ("Competition CNC'd") heads, and that's what I was recommending to the OP. That's how you make real power with a small, well-mannered cam. So my heads had the following flow numbers:

• .1 84/56
• .2 157/120
• .3 220/171
• .4 267/199
• .5 297/218
• .6 308/223

My cam was custom ground from Comp using their 3014 intake lobe and 3035 lobe on 100 110 LSA. That is 218/224 at .050" (268/276 advertised) and .570/.565" on 1.6 rockers. The engine was 10.8:1, plain old Hooker 2151 long-tubes, 52mm TB, and the ported LT4 intake.

Feel free to use these numbers for any sims you want to run. In actual use, that engine pulls hard between 2000-6000rpm and will run into the rev limiter (6400rpm) quite easily. It has a mild lope to the idle due to the overlap from the 110 LSA and aggressive ramps, but nothing like that XR288HR would have! That 288 cam has 18 more degrees of duration at .050 and similar lift on the same 110 LSA. With my heads (or the AFR 195 CNC'd heads) it would probably pull hard to 7000rpm, whereas in their test it was plateauing around 6200rpm (which is where they cut off the run, which gives people the wrong impression). That says a lot about how bad their TFS heads really were.

 

As cast AFR 195 Street head leaving something to be desired seems debatable. At the time they came out, no one would have said that....OK...maybe sub 10-sec racers. Because comp heads simulated 10whp higher, they didn't seem worth the extra cost for my particular build. (That was Tony Mamo's thought too). Whether communicated accurately or not, the 195 was considered somewhat of a unicorn when looking at the combination of flow, port speed, and potential power.

I did not save flow figures from 2008-9...though they might be in the thread were Tony announced SBC AFR Eliminators to the C4 Tech forum. FWIW...that thread got locked back then....damn posters anyway! (In fact, one poster got banned for life over the argument). I just found the post in a search last week -- so I know it's still there. Maybe the flow's have changed? Seems unlikely. Maybe your "standards" are higher than others?

That said, I can certainly understand choosing 195 "comp" heads for an HSR or MR. (Maybe even a FFI). Because one/two "visible" members pointed out the best/fastest builds seem to come with smallish cams...and AFR heads, I wondered how much higher one could go? 210 heads? More? I probably asked this to the forum and/or Tony. That's where the unique combination of the port speed -- compared to flow -- pointed back to the "as-cast" 195's being the best at port-speed vs flow.

 

As a reference 93 ragtop drove 11.19@124.6MPH 1.64 60ft with his 385 stroker, AFR 210 heads and ported LT4 intake and he was making 462rwhp and 398 tq (with E85):

93 ragtop takes it to the track - CorvetteForum - Chevrolet Corvette Forum Discussion


Rklessdriver (I think one of the best engine and drag car builder on the Forum) says in the build thread:

Quote:

So far this is appearing to be a great combination on my Engine Analyzer. This engine appears to be about 20-25HP stronger than the other 383 LT4 I built for a forum member which used a similar camshaft and AFR 195 heads....

 

I had spent a lot of time a few years back to try and figure out the head flow and the build parameters of the 10xTQ, 383 engine so that when I entered the parameters for the different intakes they would all be within reason. I also spent some time to figure out what the best cam would be for the 10xTQ engine with a stock FIRST intake. I had that already prepared and ready to go (so to speak) and was only anticipating upping the compression to 11:1 and entering a cam for the “MiniRam” engine simulation and plugging those numbers into the ET simulation.

However, I went ahead and changed the compression, head flow, and cam in the simulation to those provided by Matt. The intake parameters used are the same used for the previous MiniRam simulation. There are a few assumptions here and they’re just going to have to be what they are because I really don’t have the time to keep this going on and on. I used the same cross-sectional area and volume for “Matt’s heads” as the Competition ported AFR195s. If the specs are actually smaller or larger for either, it is what it is.

The increased compression (10.8:1), head flow, and smaller cam with the 383 MiniRam ended up making about 20 HP more than the simulated 10:1, 383 MiniRam with the TFS heads and big cam (included for reference). That pretty much shouldn’t be a surprise to anyone. What may be surprising to some is the simulated ET for the 10:1, 10xTQ engine with the TFS heads, FIRST (same length as the TPiS with the increased CSA and airflow), and a 228/228-112 cam (estimated to make 1” less vacuum than the 218/224-110 cam). It is what it is – I just entered the numbers into the program and pressed “calculate”. I will say I believe the results and you either do or you don’t – no skin off my nose either way.

Just for additional clarification, I kept the gear ratio constant at 3.54:1 and entered the numbers generated by the engine simulation into the ET simulation – feel free to double check and make sure I didn’t make an entry error. The shift points for each combination are optimized as well as the launch “Slip RPM”. Most would not want to ride the clutch like that to get the best ET, but that’s what it took to get the best ET from each combinations.

I’m not running any more simulations - yes the Miniram needs more gear to run a better time, but the FIRST could benefit from more compression and head flow as well. It could go on and on, and on,,, and is another reason I don’t like bench racing and posting simulations. Not to be a dick, but I usually don’t put this kind of time into an internet post and really can’t keep this going much, if any, longer. I don’t mind dropping in from time to time and trying to help someone out, but I have a life and a job and really need to get my own ride up and running.

So, enjoy,,, or not

 

Just curious. If you plug in a HSR or Edelbrock ProFlo how do those end up stacking up? I'd think it would slot in somewhere between the FIRST and the MR but you never know.

 

Thanks all for staying on topic and doing our best to not make this into the n+1 thread on short vs long runners, but rather just focusing on what mods and parameters result in what power for "TPI" setups, where I originally intended and meant "TPI" to be "long" tube runner setups.

Thank you so much for your time and contribution!
just to clarify, in the simulation for the FIRST TPI you set the runner length parameter as equal to the TPIS system?

 

That is some cool **** to scrutinize. Thanks so much for taking the time to do this.

So in this case, the surplus of power under the curve from ~5500-~7k for either miniram combo just isn't enough to offset the power deficit from clutch engagement, up to 5300 or ~5600 (dep on engine), that occurs in 1st gear.

Someone else may see it differently, but I see that as pretty compelling.

 

I'd love to see this too.....but totally "Get it" that BadSS isn't on here to spit out sims all day.

 

I think your LSA is listed incorrectly above....

 

I agree. Notice, the times to 80mph as well. Who's really in "the lead" above highway speed? Look at the MASSIVE torque bubble. Who has something to "play with" at lower rpms in the city? That's what I found compelling in 2009...when building a fun street car. I don't think the OP is "wrong". Nor should he feel like shooting himself for leaving power on the table. From my POV, I'd have to decide if I want to shoot myself if I left FUN on the table.

None of this means I'm blind to an HSR -- or the option to trade what? Real speed for the illusion of power? Are you sure? Or...is it to have better traction? To me, long runners (except the FIRST) represent lost power via lost traction. That is, UNLESS you have a stick. Only 10% of C4s would even have to consider that.

AFR 195 comps OR AFR 210s really come on the table for short-runner builds. LTx guys look at them more than L98 guys....for good reason. If someone built a 383 FFI using 195s versus 210's, the difference isn't going to be 20-25whp. In fact the whp of a FIRST will LOOK a lot less overall -- making the difference even smaller. Long runners simply "punch above their weight". It's hard to say this any other way.

I think most of you have seen enough to reasonably infer how other builds would compare -- using various intakes. If you are a track racer, these simulations are VERY helpful -- to dial every millisecond in. If you are building a street car, I submit there at lots of considerations versus being 2-3mph ahead/behind at 100mph. This has been my main point the entire thread. For city driving, builds can end up very close to each other -- in terms of 1/4m time. Your particular build might be a hair slower -- but it might also be a bit more fun. HOW you drive, what rpms you drive in, what transmission you have, what gears you have, and your budget can all make a difference in what you do.

BADSS helps present this in a way I've always enjoyed/appreciated. It's been 12 years since my "build". I'm still learning new things from him all the time.

Yak...You've looked at prices of used/new intakes. Though the comment was made you'd "lose your shirt" reselling old parts, you KNOW resale on intakes is very, very strong. Since you're not ready for a stroker now, I don't see ANY problem installing headers & TPIS-TPI now. When you hit the next stage, you'll get most -- if not all -- of your money back going to a FFI or even a MR....if that's what you decide to do down the road. Roller rockers can also be reused -- making them a good investment. Of course, a good exhaust too.

BTW: When I built my 383 10-12 years ago, intakes were going for $700-$800. ($350-$400 each for base/runners) FFI intakes were similar. You see what they cost now. I have an HSR I could sell for more than I bought it for,. If it doesn't have a moving part, coating, etc...that degrades, used parts don't necessary hit you in the shorts. Consider a pun on the phrase "Pay as you go". Here, it could be "Play as you go!" LOL

 

yakmastermax - Just to clarify, in the simulation for the FIRST TPI you set the runner length parameter as equal to the TPIS system?
Yes, used the same length for the FIRST as the TPiS. Used the TPiS file and just upped the runner diameter to 1.75” for the area calculation, and entered the increase in flow for the FIRST.

KSA Aaron - I think your LSA is listed incorrectly above....
I saw that, but he said later “on the same 110 LSA”, so I took it as, and entered it as, a 110 cam

jdjenk - Just curious. If you plug in a HSR or Edelbrock ProFlo how do those end up stacking up? I'd think it would slot in somewhere between the FIRST and the MR but you never know.

There’s an earlier sim posted (#219) of the HSR and the FIRST on the 10xTQ (236/242-110) model. You can look at the table in that post listing the different power levels of the intakes and see that the HSR curve would look more like the MiniRam curve, just with more power through the entire range until 5800 rpm (or vice versa). I had already run these ET sims before for the 10xTQ (236/242) – so it only took a few minutes to cut and paste these. If you meant ET wise, looking at these, yep, pretty much in the middle for the 60ft, 330ft, and 660ft ETs.

 

KSA Aaron, thank you for catching my typo on the LSA! Yes, it was supposed to read "110." I corrected the post and I'm glad that BadSS assumed the correct LSA in his sim. Sorry!

BadSS, thanks again for all this very interesting data!
I know you know this, but just for anyone thinking that's not a huge difference in power...you're right, but the huge difference would be in the "street manners" of idle quality, MPG, the ability to lug a high gear, and just generally enjoy the car on the street. IOW, what's impressive is that the good heads and higher CR allow more power while being a vastly better street engine. some of that can't be measured, but you can see that below 3200rpm my engine was trending toward making considerably more power than the TFS/288 engine. If the article had run the test from idle, you'd get a lot better sense of how much better the good-heads/small-cam combo really works.

Likewise, if the tests were run from idle you'd see the FIRST combo come back to my combo at lower RPMS, too. You can see that trend developing at the 3000rpm low-end cutoff, where the 10xtq/TPI torque is headed into a crater. The FIRST combo is coming down on the low end too. Off idle to around 2700rpm(ish) on an otherwise identical engine, the FIRST and MR should have pretty similar performance because the FIRST's resonance tuning hasn't kicked in yet.

Quote:

Originally Posted by GREGGPENN

I agree. Notice, the times to 80mph as well. Who's really in "the lead" above highway speed?

Well...not really. These sim runs were set with high traction. Given that the FIRST setup in this sim had the power advantage until 5300rpm and that all cars had identical gearing, the sim gave the FIRST car a big acceleration advantage up to 39mph vs my engine. You see that reflected in the 0.13s difference in 60ft times, which is huge. In fact, that would predict a much bigger deficit in ET at the end of the quarter mile: the typical "rule of thumb" is that your 60ft time is about 15% of your ET, and that predicts my engine loses by 0.8s. That's why it got to 80mph faster, not because it actually accelerated harder all the way to 80mph. In fact, my engine was faster everywhere after the first 60ft. So the FIRST engine only had the advantage for the initial 60ft and 40mph...in the sim.

However, the problem is that for most of us that 60ft time difference isn't real. While you might have the traction to actually hook up 1st gear on drag slicks, that won't happen on street tires at these power levels. Even with 3.45 gears, my car in 1st gear wouldn't hook up from a roll, much less attempting a launch at 5300rpm. In the real world on street tires at these power levels, the 60ft times are going to be traction-limited rather than power limited. So the extra power below 40mph would be worthless on anything but real drag tires. The real takeaway is that after the 60ft mark (~40mph) my engine made more power and accelerated harder for the entire rest of the run. IOW, on street tires my engine is either equally fast or faster at all speeds: at any speeds where the FIRST engine would have had the advantage there would be nothing but spinning tires from either engine.

My wording there probably implies disdain for the as-cast AFR 195 that I didn't intend. They are obviously great heads at their price point. All I meant was that the Comps seem to be better in every way, including general port velocity, as indicated by their low-lift flow numbers that are actually better than the as-cast 195's. IOW, the CNC porting they do is clearly not aimed at hogging out the ports but rather more subtle improvements to port shapes and corners, which improves velocity at any given pressure gradient. OTOH, if you compare the 210 Comps to the 195 Comps you can see that the bigger port volumes really are "lazier" at low lifts: the 210 Comp is actually worse on flow below .500" lift. The guy who did my heads (I don't think AFRs existed back when they were done) was Greg Good in Houston, and he's well known for getting big flow out of small port volumes and concentrating on keeping velocity high. So they're a natural comparison to the AFR 195 Comps in both philosophy and performance. Other than price, there is only upside to going with the 195 Comps vs the as-cast 195s as far as I can see, but there is a downside to going with 210s (and it therefore just depends on your build and intended use).

 

Matt, this isn’t a simulation of your engine – it’s modeling the 10xTQ 383 “short block” with a bump in compression to 10.8:1 and the specs for your heads and cam with the MiniRam (don’t know how much difference there is between it and your LT4 intake). Plus, the FIRST is modeled with the 10xTQ “long block”, using the lesser TFS heads (if you will). I'm not running more sims, even though I expect someone might say that the FIRST being a LTR couldn't benefit from the additional flow, which would not be correct.

I don’t know what you’re looking at, but the FIRST is .16-seconds faster at the 165-ft mark – that’s a .03-second differential and means the FIRST has accelerated faster to the 165-ft mark. Saying another way, it took the FIRST 1.39-seconds to go from 60ft – 165ft and it took the MiniRam 1.42 seconds. The lesser MPH at the 165ft mark is 60, so the FIRST is definitely accelerating faster to 60MPH.

It took the FIRST 1.63-seconds to go from 165ft to 330ft and the MiniRam 1.62-seconds. The lesser MPH at the 330ft mark is 77.4, so somewhere between 60 and 77.4MPH, the acceleration difference levels off and the MiniRam makes up a little ground – I’d guess around 70MPH, maybe a little less, since the FIRST shifts into 3rd about 65mph and the MiniRam is still in 2nd.

While the advantage of the FIRST/TFS shifts to the MiniRam around 70MPH, where the MiniRam really starts showing its advantage over the FIRST is after the FIRST shifts into 4th at the 545ft mark around 90mph. Remember the FIRST is modeled with the TFS heads.

 

Comment on tire diameter: A 315/35R17 tire runs about 810 revs/mile. The effective diameter is therefore about 24.9" while rolling. This will tend to shift the various speeds (in MPH) mentioned above down by about 4%. Not a huge difference, but worth mentioning and/or correcting for if you are willing. I'm not sure why there is such a huge discrepancy between (publislhed) dynamic rolling radius and static tire diameter. Seems to be an industry-wide issue.

Nitto tires canada says 503 revs/km (or about 809.5 revs/mile) for the NT 555-G2 in 315/35R17. Revs/mile is not listed on the normal (US) Nittotire site.

17 315/35ZR17 XL Review placard 106W BL 11 211340 10.5-(11.0)-12.5 25.7 12.6 2094 320AA A 503

https://www.nittotires.ca/search-res...15&ar=35&rd=17
https://www.nittotire.com/car-tires/...formance-tire/

 

Understood, I was just calling it "my engine" as shorthand - easier to type than "10xtq MiniRam Miller." As we've seen, my typing needs all the help it can get! I'll just call it the "Miller combo" below (I don't really want to use "MiniRam" or "MR" because there's the other MR combo on the dyno graphs, and that could get confusing for others trying to read all of this).

I agree that the heads are a confounding factor. The fact is we can't know how/if the TFS heads are hurting the FIRST combo. They obviously don't flow well at high lift values, but I don't know about their flow at low lift (i.e. their port velocities). If they actually have good velocity but just small port cross sections, then they might not hurt the FIRST combo much at all. If they have crappy flow even at lower lift (which is entirely possible) then they do hurt it significantly. Likewise, bumping displacement from 383 to 396 would increase the power disparity between the two intakes. If the OP is going to go through the expense and effort to build a stroker motor from his stock block, then I can't think of a good reason for him not to build it as a 396 in this day and age.

Yes, but all of those advantages further down the track are purely a result of the speed advantage the FIRST combo had at 60ft. 1.7mph doesn't sound like a lot, but these gains in the first 60ft snowball into bigger gains further down the track. If both cars had the same FIRST combo and you start a roll race with one going 39.3mph and the other going 41mph, the one that started at 41mph is going reach the 165ft mark sooner and be going faster when it gets there. That has nothing to do with power and everything to do with which car started off going faster. You can see that the Miller combo already clawed back 1.0mph of that deficit at the 165ft mark, and after that it's going faster at every marker and it gets there quicker from the previous marker.

The bottom line is that the car putting more power down at any given point on the track will accelerate harder at that given point. The Miller combo has the power advantage everywhere above 5300rpm in this sim. During the run, there are only two brief points where the FIRST combo has more power: 1) from 0-60ft, where as I said traction will be the limiting factor on street tires rather than power; and 2) from 132-151ft, right after the Miller car shifts into 2nd. During every other part of the run the Miller car is making more power and accelerating harder. If both cars hit the 60ft mark at the same time and speed - which is how this plays out on real-world tires - then the Miller combo will win by a significant margin.

Some might be thinking that I'm making excuses when I say that traction will nullify the 60ft advantage the FIRST combo showed here. However, if you show up on the kind of tires and have the kind of skill it takes to get a 1.61 60ft time in a C4 with a ZF6 and stock suspension (i.e. if you're that serious about drag racing), then you aren't going to show up with 3.54 gears in that Miller combo either. If you gear the Miller combo to shift at the same points on track as the FIRST combo, then even the 0-60ft power advantage of the FIRST combo will shrink to virtually nothing and the Miller combo will walk the FIRST. The reality is that neither the OP nor I would ever be in that situation, though: we're the "real-world-tire" guys cutting 2.0 60ft (on a good night) with real street tires, all of which is traction-limited and which negates the FIRST's power/acceleration advantage to 60ft. Even more importantly, we're the guys accelerating from a roll or a stop light, so the 1st-gear/0-40mph power advantage of the FIRST in this sim just doesn't matter to us because it will only create tire smoke.

The Miller combo had big advantages at the following marker intervals:

• 76ft-117ft
• 196-351
• 479-1320

Between 351-479 it is roughly tied in power/acceleration with the FIRST combo. The Miller combo did lose out from 117-151 because of the shift into 2nd (the next two shifts don't even drop it below the FIRST combo's peak power because the gears ratios are closer).

The HSR is the better intake over the MR since it barely sacrifices any peak power or RPM but does pump up midrange power significantly. It'd be a no-brainer if it fit under the hood of a C4. I know some folks have modified them to fit by lowering the plenum, but I've never seen a test of that against a stock HRS to see how it affects flow. I don't know enough about the ProFlo to say, except that it seems like it would act a lot like the HSR and have similar hood clearance problems.

 

A proflo by all accounts fits just fine as long as you use a LS1 throttle body. If I ever decide to move away from a stock engine it will be what I use.