I hope someone does try it on a 400 plus cubic inch motor. If they do and have success then good for them. I am not jealous of anyone who puts a motor in a C4. I am a car guy all around in fact.

What I am saying is that it's a gamble for someone who is building a stout motor because the SR, and MR have been tryed and proven.

Our C4's are light cars for street cars as it stands. I would rather have 30 more hp, then 30 more tq.

Take care!

 

Teaser.....(that answers a few objections).

FWIW....This quote is from a builder who owned/ran his own speed shop for a few years.

 

One more thing I should say....

It's all about the Finite Amplitude Waves, baby! All about them waves!

 

This is what I base my opinion off of. I'm sorry for the crappy pics but you get the idea. The printouts are faded and my cell camera, it would appear, is less than adequate. All dyno's were done in the same facility on the same dyno though on different days. All numbers were corrected.

The first pic here is a modded L98 6 speed. A red 1990 with black interior to be exact. It was mine. It had headers, no cats, free mods, air pump eliminator. It made alot of torque and was fun to drive. The peak numbers in this dyno are 228rwhp and 331 rwtrq. Look how fast it falls off. I'm sure a superam is better, I've even installed a couple of em on other peoples cars. This is stock style TPI.




Next up is a (poor quality) pic of my LT4 when it was bone stock down to the paper air filter with 50k miles on it.
Peak numbers were 302rwtrq and 298rwhp. It does not drop like a rock above 5800rpm, in fact it stays pretty good with a drop of about 10hp by the rev limiter at 6300.



Last pic here is dyno of the two superimposed on the same graph. The L98 by this time had the above mods plus a ported superam base intake, SLP runners, ported plenum, thinner head gaskets and a good valve job. It made 248rwhp and 335rwtrq.
The other is a random dyno from my LT4 stock. In this particular one it made 293rwhp and 301rwtrq, close but still less than its best numbers.
This is as direct a comparison as can be made IMO. The modded L98 has the advantage early on but is overtaken by 4400rpm by the LT4. So, in 1st gear the L98 will have an advantage up to 4400rpms. Beyond that the shift points dont let the rpms drop back far enough for the L98 to have more HP or TRQ than the LT4 car. Interestingly enough, the LT4 makes the same or more torque/HP than the modded L98 below 2000 rpms.








As for track results, the stock LT4 trapped the same MPH as the modded L98 but was .2 tenths quicker. With 4.10 gears only it ran a 13.009 at 106. With headers, gears, hotcam and mail order tune it runs low 12s at 114-116mph.

 

Why would you want to use an LSx throttle body, when anb AS&M monoblade is available?


It works great. I have one, great streetability and breathing. The combination of adding that and ditching my restrictive procharger intercooler increased max boost from 8.5 to 12.5 psi! With the same size pulley !

 

The important thing -- for this thread -- is the sentence I bolded above. The SR is better. About 1000rpms better. BADSS mentioned in an email to me that he feels the FIRST can outperform a SR. Since it's measured above 300cfm in flow, it's hard to imagine it wouldn't.

Based on graphs, dynos, and times that I've seen the stock SR and FIRST will finally be overtaken by MR/LT intakes around 5500rpms. That means, not all TPI intakes are created equal. (Having owned, mega-ported, and installed a set of SLP runners myself, I can say they are crap out of the box. The tubesize is pathetic. The casting is worse. I wouldn't recommend as-cast SLP runners to my grandma.)

With the extra air before peak is reached, you'd see a whole lot more advantage of a FIRST than your SLP/TPI setup. I agree with Ron, I think the FIRST would win. HOWEVER...Once you build to the point that off-line traction becomes a serious issue and/or you can pull way past 6k rpms, then the FIRST isn't the best choice.

The FIRST is a great intake to significantly impact sub-6k applications where you want to leverage that strongest 2nd-harmonic reversion pulse. It can add 10% to your intake charge.

The reason sub-2k power wasn't improved with a TPI is due to the restrictive runner length. Again, that 300cfm breathing capability of the FIRST aleviates most/all of that.

I would have used a FIRST on my 383 build were it not for goals regarding looks and the price I found for used TPI aftermarket stuff. It's too bad Todd (Z51L9889) hasn't finished his 4-yr-long project. He was building a 383/FIRST/AFR195 combo. I've been looking forward to the results for a long time. IIRC, he was hoping to break the 420rwhp and 520rwtq barriers.



Final note: The as-cast SLPs are barely over 1.5" ID. A modestly ported FIRST is 30% larger. Even with maximum porting/honing, the as-cast FIRST would win. Do the same to a FIRST and your sure to extend it's advantage over a short-runner intake into the 6k rpm range. Plus, have more power all the way there.

This intake isn't for people looking for track times. It's for people looking to maximize the rpm-range of a DD.

 

For a max effort big cube engine, the FIRST probably isn't the way to go. But I can see it has it's place out there. I would actually like to try one on one of my engine builds for somebody to have hands on experiance. Miniram engines are capable of 9's N/A, Dave (Hooked up) has proven that. Super rams are capable of mid 10's Willie (383 vette) has proven that. I would like to see what a max effort FIRST would do in the 1/4 on pump gas. A FIRST built engine that was maximized for that intake. The biggest cube motor that would still work well with it, and everything else built around it. 383,396,406,409. I would give somebody my cost on parts to build one and see what a max effort FIRST would do. I would consider doing it real cheap for the labor. It would be interesting. I like Minirams and Super rams, just because I have built a bunch of them and know what they will do. Timeslips tell everything. No flow numbers, no dyno numbers... the real deal. But to do a max effort engine built around a FIRST might be interesting.

 

Greg,
The FIRST is a long runner intake that is not designed for high RPM operation. The runner length of the FIRST from plenum to valve is 22" and that is designed to operate in the 4000 to 5000 RPM range. After that the long runners are going to work against the engine as it rev's higher. The amount of air that it flows is impressive but the amount of air flow potential does not help above 5000 RPM when the intake is out of its tuning range. This intake would work well on a big cubic inch engine operating below 5000 RPM. If you want to make power above 5000 RPM I would recommend a ported superram, stealthram or miniram intake because they will perform better. Like I mentioned earlier the builder has to decide what power band they want and then choose the intake that achieves their goals.

The ideal peak operating RPM of the FIRST intake is 4000 to 5000 RPM, Superram is 5000 to 6000 RPM, Stealth ram 5500 to 6500 RPM and miniram really has no practical ideal operating range because the runner are so short it would tune in at 8800 RPM but the runners are too small to flow enough air at that RPM. Instead the miniram works on an anti tuning principle where it never hits it ideal tuning frequency but instead delivers a flat torque peak from 2000 RPM to 6000 RPM which helps it make power at high RPM.

 

Interesting thread.

I'm not a fan of the long tube runner set-ups, I think they choke a system to the point they're equivalent to a restrictor plate. But, I'm not sure we can lump a First Intake into that category.... or at least until we learn more about them. From reading part of this thread, it sounds like some have stepped up and are giving it a try. (I applaud this !)

I'd like to see some real-world results from somebody who is an experienced dragracer and knows how to get the most out of their set-up..... if the First intake can perform on-par with the Superram, then its a darn good intake choice for most people here who run street gears and/or tight converter with a hyd cam. It needs rpm to do it though.... there is no other way around it, its gotta go to 6000 rpm, otherwise it'll be behind in an acceleration contest if both combinations are properly set-up.

Actual track C4 comparisons would be nice.... we know a few things about the other intakes.

- Ralph - 85 C4, Superram, 350, AFR 190 street, 219, 3.45, 2800 conv, approx 3300 lbs, sea level track, good air = 11.62 @ 117 mph

- Me - 85 C4 old set-up, 383, Superram, AFR 190 street, 219, 3.45, 3000 conv, approx 3300 lbs, 900 ft track, decent air - 11.32 @ 119

- Willi (383vette) - C4, Superram, 406, 2800 rpm, ?? on the rest, not sure on track or air = 10.5 @ 127 mph, (I think)

- Vic - C4 - Miniram - 355, ported D-ports, 219, 3.73, 4000 rpm conv, sea level track, good air = 11.3 @ 120 mph

- Wheels-up - C4 - Miniram-355 (Vics motor), 4400 rpm conv, 4.11 gears, approx 3000 lbs, sea level track, good air = 10.9 @ 122

- Josh - C4 -383, Miniram, Manual 6sp, AFR eliminators, 3.73 gears, 230/236 comp cam, approx 3300 lbs, sea level track, good air = 11.3 @ 122 mph

- John Mackey - 350 old-set-up, LT-1, ported heads, hyd roller cam, 3.73's, 3600 rpm conv, approx 3300 lbs, sea level track, good air - 11.5 @ 118 mph (or thereabouts)

- LT401vette - C4 - LT-1 396 (actually overbored to I think 405 ci), AFR heads, tpis 242/242 solid roller, 3.73, 3400 rpm conv, sea level track, good air = 10.6 @ 128 mph

Most of the above times are feasible by anybody and many others here over the years have had similar et/mph results with like set-ups.

The final thing to do on this is to fill-in-the-blank with the First set-ups that have been raced.....

- ?? C4 - 350 - First intake - ??? = ??@???
- ?? C4 - 383 - First intake - ??? = ??@???

I think if we fill in those blanks, the story will begin to be told.

 

Have you run one? Know someone who has? Compared it to the superram via direct intake swap?

I know two people here who have. One is an experience racer with 200+ passes.

 

There are a few members here who have installed the first maybe they will see the thread and chime in.

 

When you talk about harmonic tuning or wave tuning there are different waves depending on the runner length and rpm range. True, the 3rd harmonic range for the First would be in the mid to high 4000's.

However as you go past that range and into the high 5000's you begin to pick up the 2nd and strongest harmonic range. This one lasts maybe 1100 rpm with the peak say around 6400 rpm.

Does this concept work. You bet it does because people at the EMC for example use it to great success. It just so happens I am in the process of doing that very thing. I am highly modifying an Accel base, making my own 2" runners and modifying a factory plenum.

By the way my current setup with a First base, modified SLP runners and modified factory plenum makes peak power around 6500rpm. I am above 400rwhp and 400rwtq as the cars sits. It is a 368 cube SBC. I will be at the Los Angeles Invasion for track times. After that I will install the new long runner intake system and fine tune it. I do have progress pictures if anyone is interested.

Back to the First. You can open up the base at the runner entrance to 2" inside diameter. If one wanted to make their own runners you can use 2 1/8" 16 gauge bends with a 3" radius to make the runners. No problem at all to open the plenum to accept the runners. The intake base can be open up to a Felpro 1206 with ease where it meets the head. With a little welding a Felpro 1207.

In fact this project is now under study and may very well happen using my current setup on the motor as a starting point. It would be going into a 1970 El Camino from yesterdays discussions.

Edit: I forgot to say those dyno numbers were through an unlocked 4L60E.

 

I agree with you but I believe the second wave will hit its peak around 7000 RPM which is too high to be of pratical use for most people and the intake is not capable of supporting enough flow for a high RPM engine. That being said I would like to see some dyno work with this combination and second wave tuning to see what it actually does on a real high powered street/race engine.

 

I was thinking it was lower than that. But, it's a good point. We talked about this before....
http://forums.corvetteforum.com/c4-t...-thoughts.html

 

that would be sweet!

 

Id like to see how it stacks up to a superram I bet they are fairly close.
Given the out of box flow on the FIRST guessing it would pump up the low-midrange over the SR?!
Maybe upstairs lack some due to sheer runner length but it would be interesting to see as the stock SR runners arent very big in dia.

For a smallish cammed stroker it could be a lot of fun on the street.
Good to have alternatives.

If I got another C4 would have to find a way to get a FIRST on there and pass it through smog somehow. A mild 400 would be chitload of fun to have as a DD.

 

I made a mistake in my calculation and it should actually peak with the second wave around 6500 RPM depending on the cam duration. It would be an interesting test to see what actually happens at those RPM levels with a FIRST.

 

Thats pretty much what I was saying and or asking.

Thanks Todd.

 

I pretty much agree..... and considering the Superram is no longer manufactured.... it would be great news for TPI owners if the First is able to produce similar type performance. Something is necessary that fits under our hoods to fill that void in that rpm range. When I was younger, I would have already tested it..... I move much slower these days.

In my opinion, if the First Intake can get up close to the rpm capability of a Superram, and it sounds like maybe it can, then it can easily compete with it. With the key being average HP over the final 1800 rpm of the motors operating range. Which to me is the most important thing to look at when trying to accelerate fast on a appropriately set-up street/strip C4.

 

Not sure what you said before, I am guilty of not reading the entire thread..... but you're welcome anyway