yes but then u need either wiring adapters for the ls7 injectors or else an aftermarket rail which will add to the price of the ls7 intake. it woul be fairly close. within a few hundred dollars and at this point in the build you are not going to get cheap.

 

SDPS has a deal on the LS7 intake and it comes with rail and injectors and a TB. You sell the TB for 200 and then get the intake and rail and injectors for a very reasonable price.

 

****, is there any point these builds that are cheap????????????

 

as im learning.........NO!

 

I disagree I would put my money on the TFS heads vs LS7 heads in this match up, from the dyno graph I would say the difference in peak power is closer to 20-25 hp.

With the big gain in torque across the range, with less hp for 300-500 rpm, the LS7 head motor would not have the power to over take the TFS head, keep in mind even with a close ratio trans you'll have close to 2,000 rpm drop between shifts, you factor in a 2,000 rpm range drop and the TFS head car will spank the LS7 combo that was dynoed PERIOD.

The power band is also lower, I don't care what anyone tells you, the faster you spin a motor the more likely failure will occur, faster springs and engine will wear. I'd rather have 20 less hp, shift it 500 rpm sooner and have more torque everywhere. There is no debate, in this test the TFS head is clearly the winner.

 

The Fast is having trouble feeding the 440 up top. In a few weeks I'll have numbers with TFS 235's and the Wilson Billet Bank intake. It should carry out the power VERY well. I have a lil less cam and a lil more compression than the test motor.

 

That is your opinion. Not a fact. If you shift the tfs car 500 rpm earlier, everything else being equal, you will get outrun. Why would you not, look how hard the power drops off after peak compared to the ls7 head.Plot where the hp is on the two curves with a 500 rpm difference, with the ls7 having the upper rpm point. The faster you spin a motor, the faster the car goes. Rate of acceleration may drop as a result of passing peak horsepower, but the car will go faster. Law of nature there. Horsepower has nothing to do with speed, rpm and gearing determine speed. Horsepower determines rate of acceleration gien a constant of resistance (weight, drag, etc)

The fact is this is a loaded test. If you put one of the two camshafts designed for the ls7 heads in and run it with both sets of heads, you would be amazed at the difference.

 

how do u figure? the tfs head will be in the more powerful power band way longer then the ls7 head? and whos to say that cam was designed around the tfs head? seriously i among others dont understand your logic but thats is your opinion right?

 

Look up the Vengeance cars and check the resuls from them. Specs look awful similiar to me

 

I know when I wanted to run a 416 ci motor Cary @ ETP talked me out of the ETP 245/fast 90 setup. He was very confident that the LS7 heads/ls7 intake would perform better on the dyno and at the track. Since he sells both heads (and both are expensive) he had no reason to lie.

I would still put my money on the LS7 setup for big cubes that are willing to turn big rpm's with a well suited custom cam.

 

I agree, this is a loaded "comparison". Based off of what I've learned from listening to others is that the LS7 head is very sensitive to overlap and does not require a HUGE cam to make good power. The cam being the ultimate deciding factor in this "comparison" is not optimal for both setups to determine a true "winner". So on that note, I agree with Stang Bane.

 

[QUOTE=transAm-98;9223294 He made 470/495 (yes 495 rwtq in an N/A 347). [/QUOTE]

In BIZARRO WORLD.

 

Not a bad comparison. But I do agree that both cams need to be optimized for each head as long as they are in the same size area.

Does any one have flow numbers on the TFS 235's? I just bought some 235's for my 416 and can't seem to find any flow numbers. I will be running a smaller cam with more compression and a ported 90/90. I just don't want this thing to fall on it's face up top. I didn't think you could run the LS7 heads on any thing smaller than a 4.125" bore?

As far as the 470/495rw 346. Is there any way possible that it was done with a large stall auto. I know on my old 383 the stock converter it made 408/405rw. With the Vig 4,000 stall it made 350/450rw. Just a thought. I agree the numbers are scewd.

 

Just being a novice at this and I am sure most people on this board know lot's more than me, but I would take the trickflow powerband shifted at 6500 vs 7000 for the LS7. The average power numbers are for trickflow 543/518 with a 4500 to 6500 pull in the gears beyond first. The trickflow with definitely pull in first on anything except an auto with a stall. The LS7 is 566/495 at 5000 to 7000 RPM. Looks like a tradeoff, however the trickflow lead is almost 1300 rpm of the 2000 RPM gear pull. The averages are, LS7 +23HP and -23 torque average, so that is close to a wash. However the trickflows lead for over half of the compared powerbands. Besides, torque is what accelerlates weight not horsepower. Horsepower is just a mathematical function of torque X RPM.

 

262/270 cam on an LS7 head? You'll never see a good running, sub-7500rpm LS7-headed engine with a cam that big. The graph clearly shows the LS7 heads need more RPM to make best use of that cam. If the valvetrain/shortblock combo is not capable of the RPM that the LS7 heads need with that cam, then it's just a bad combo falling short of it's potential. The LS7 heads need far less intake duration for that RPM range.

 

I agree with DRZ as well!

The LS7 would need less intake duration with it's bgger cross section and then it will make more bottom end and still make the same top end due to the manifold.

I like both heads though as the TFS has a great cathedral port head that's easy to get as well.

Tony's AFRs always run great too but I would like a bigger model as well like TFS has here for the really big engines.

The LS7 head is great and has a nice manifold but you can't put it on the smaller bore engines.

 

Airflow Chart for GenX Street/Strip 235 Cylinder Heads
Lift Value Intake Flow CFM Exhaust Flow CFM
0.100" 65 55
0.200" 144 124
0.300" 229 196
0.400" 287 242
0.500" 323 260
0.600" 340 270
Tests conducted at 28" of water (pressure) with a 4.125" bore flowplate.
CNC-profiled chambers; exhaust with 17/8" pipe.

 

“We put together this dyno information and posted it not to throw stones at the LS7 heads, but to share the information we learned. Stangs Bane has posted that this is a loaded test, which is pretty ridiculous. We used the camshaft that we felt would be representative for the typical combination our customers are putting together, and also based on what the camshaft experts at Lunati thought would work well.



If we wanted a “loaded” test, we could have done the following:



Used a smaller CC head for our vs LS7 to give the TFS 235 head an unfair compression advantage

Used the same style valve (put titanium in the TFS 235 head, or s/s valves in the LS7 head)

Ported the FAST intake and left the LS7 stock-we did not touch either one

Done a special valve job or additional porting to the TFS heads-they were pulled directly from our stock and bolted on-exactly as we sell them.



For that matter, we will re-run the test with the same rocker arm ratio between the two. As we mentioned, we are using the standard 1.7 ratio rocker arms vs. the 1.8 ratio LS7. We ran the test with two disadvantages-heavier valves, and a lower ratio rocker arm. Our dyno is also somewhat conservative compared to other “well known” engine dynos that we have witnessed. Tony M was very correct in his analysis, and we appreciate his input as well. The main point to learn from this is that you can build a “killer” street engine with the cathedral port heads that are out there, readily available.



The reason we posted the information is that most engine shops, and most readers of this forum, do not have an engine dyno but are probably curious about what part makes what HP. Further, most shops that have a chassis dyno will not compare one head to another “just because”, and in reality an engine dyno is a more exact tool than a chassis dyno (plus changing heads and cams on an engine dyno is WAY easier than doing it in the carJ). We have the resources and people to do this and felt the group would find it interesting.



If anyone wants to make any further statements or say the test was loaded, please save the bandwith. If you want to discuss this with us, PM us or call-we would be glad to discuss what we did and why. As we hope you can see, we are very open to sharing this information and definitely will say it has been interesting watching the posts.





Trickflow Tech

 

I guess you had no idea that Vengeance has built 3 cars with these heads and a camshaft with VERY similiar specs??

Whatever you say.

I am not saying that there is anything wrong with your heads. They have been proven to generate very good numbers.

All I am saying is that a back to back, apples to apples test between ls7 heads and any cathedral head is going to be next to impossible given the extremely different camshaft requirements for each cylinder head.

Most of the time a compromise for 2 different sides is not very good for either. I am guessing this wasn't one of those cases.

 

I'll stick up for any aftermarket company (AFR,ET, TFS, Dart, Profiler, ALL Pro etc.) that provides ACTUAL test info to enthusiasts where the recipe is clearly stated.

I'm not sure how this post could have been any more apples to apples. If anything it was biased toward the LS7. Same shortblock, bigger rocker ratio, larger ports, the biggest cubic inch to suck up the air, putting better valvesprings on the LS7's so they wouldn't go into float to early, etc. Surprise surprise, the 7's make more top end power than the 235's. Suprise surprise, cathedral ports make killer low end like Sperry intended.

Now for my rant:

Why is anybody trying to shoot holes in it other than entertainments sake? Had TFS wanted to bias the test, they would run a small cam that ran out of steam before the larger LS7's airflow could make a showing. This cam is an average choice for your average 440ci stick guy..remember the guys that aren't happy with "mere" 427's and they want to pump a big horsepower number. Certainly TFS doesn't need advice about cams any more than Tony Mamo or Craig from ET would. They talk to their customers ALL day long and KNOW what their average customer demands of a certain cylinder head model. Had it been a 215cc runner model in the test, their average customer would want something along the lines of a 230@.050 grind.

Why is it that someone can **** talk, but when it comes time to back up they're talk..they say "company X tested it". Buddy, if you ain't company X, what are YOU doin' posting on their behalf?

If you don't agree on the split, I don't see that it's helping the 235's in particular either. New Rule for the forum, unless you know valve opening and closing numbers independently of two cams and know which events affect what from personal experience with different heads, don't post your "opinion". I read these posts all the time and it kills me there are people naive enough to listen to guru so-and-so's kung-fu chop-suey double-secret engine combo #273X. Unfortunatly on any forum, there's a bunch of keyboard engine builders who've never seen an engine dyno in their life reguritating interweb info.

Note to the newbies: Ask this question before you take someones advice: have they ever sold any winning racing engines? How much time have they spent on the dyno sweating and burning their fingers? Actual engine DEVELOPERS don't hand any valuable information out to people who haven't earned it.