As some of you know I'm building up a 369sbc motor. It has the AFR 195 heads and a Mike Jones 233/233 camshaft. For the dyno I used a Victor Jr. intake manifold and a Holly 750hp carb. I'm going to have the Victor Jr. manifold flowed to see how much cfm it will flow. I bet it is less than my ported TPI First intake. Here are the results. Best dyno numbers with the long tube headers was 526 horsepower at 6500 and 471 torque at 5200rpm. Best dyno numbers with my custom chasis fit short tubes was 524 horsepower at 6500 and 466.5 torque at 5300rpm with the same conditions. We switched to Mobil One and let the intake manifold cool off but kept the oil hot and we managed to squeeze 535 horsepower out of the shorter tube headers. This motor only likes a total of 30 degrees timing. With the longer intake runner tubes of my First intake manifold I think the torque will come up somewhat. I'm going to find out how much the Victor Jr. flows and compare that to my First. So I expect the rwhp with my 4L60E to be around 430. That should get me deep into the 11's.

sweet ride man.sounds like u got lots of work into the motor got ne pics.

Not bad, Not bad at all!

Congrats again Allen!!

That little hunk of "no compression, sissy azz hyd. roller, CA SMOG legal " engine you bolted to that very conservative DTS Dyno today impressed the hell out of a few very "hard core" guys today! You Da Man!

I hope Don can sneak you in real soon for the swap. ( Hint, Hint, I KNOW that you are reading this Don!)

Talk to ya later Allen.............

1989GTATransAm --> What was the brand and size of the Shortys and Longtubes?

I had Dyno Don build me up a set of 1 3/4" custom short tube headers to fit my car and the exhaust termination boxes. Bottom line from the test is from peak torque on up the shorter tube headers were only down 1.4hp on average to the long tube headers.

In my motor that would be from 5000rpm up to the 6800rpm shift point and that is the rpm range I would be using going down the track. So there is no real gain from a 1/4 mile perspective with long tube headers over a short tube header when using a quality short tube header. That is why Dyno Don's headers perform so well in our cars at the track and on the dyno.

Hey Pat, thanks for all the help. Yep, not bad at all considering the exhaust system is the one that will be going into the car and not a special set of dyno only headers that won't fit into any car.

Here are some pictures of the engine on the dyno. You can see the twist and turns my headers have to make to fit in the car. These are the long tube headers.

Here are my short tube headers.

That's some very strong numbers for a SBC!!!!! Should be a blast to drive with that kind of power! Very well planned and thought out build!

wow shorties dont give up much power at all!

Impressive numbers, it will be interesting to see how the TPI compares to the victor Jr manifold.

Do you know what lobes he gave you? You running the LSx cam journals right, so are you also running the LSx based lobes he has or his hydraulic series? Just curious as I have a 233/233 cam by him in my turbo motor and was interested to see how it compares to yours. I was hoping my motor to peak closer to 5800 and so far i havent seen it, possibly due to problems with the turbo housings creating backpressure

Is the 369 a short stroked 350, or a destroked 400?

Very impressive #'s. Im also looking forward to seeing the flow comparison to youre intake. Reason being, im builing a 383 and ill be using the whole FIRST system. Wich should flow i guess similar to youres.

Hi Orr. All I can tell you is that the lobes at .006" are 280/280. The lobe lift is .360". With my 1.65:1 rockers that is .594" of lift. Mike Jones was right on the money with this camshaft. I told him I would like to see peak torque around 5000 rpm and max horsepower at 6500 with a shift point of 6800 to 7000rpm. It does exactly that. We took it to 6800 and it was just starting to nose over so we did not see any need to go higher. The horsepower was flat from 6500 to 6800.

The motor is built with the new Dart SHP block. It has a bore of 4.060" and a stroke of 3.562". Compression is 11.1:1.

I really don't think my First intake system will give up anything to carb system I was running. If I wanted more horsepower from the dyno I could have gone to something like a Super Victor and maybe an 850 Demon. Seeing as a fuel injection system will actually be going on the motor I did not see a need to persue the carb thing any further. I just wanted to get a feel for what the motor is capable of doing and do the header test.

There is a thread on my intake system. My First has been opened up somewhat especially ports 1 and 8 as they narrow in the middle. I think it flows around 320cfm. My runners are highly modified SLP's with maybe 3/4 inch of actual runner left in them. The rest is siamesed and plenum. I'm also running a mono-blade throttle body.

Ah, thats an aggressive cam. Mine is 292/292 with the 233 lobes, .564 with 1.6's

Thats kicking some butt man, 6800 rpm is fun, you'll love shifting up there. My 383 sounded unreal at that rpm

I thought I had good numbers for a set of dyno dons shorty headers. I have 396 hp and 407 ft lbs at the rear wheels with a set of shorties

You do. Those are great numbers. These numbers are from an engine dyno. RWHP numbers are to be determined but maybe in the 430 range with a 20% loss.

Here is the best dyno graph with the headers that will be going into the car.

cool thread.


are u happy with the results?

"are u happy with the results?"

Yep. Anytime you can get 1.43hp/ci with the headers/exhaust that is actually going in the car I will be happy with that. One more item is the camshaft that is installed in the motor was designed to be used with a EFI system and pass California smog. The one in the motor has a 113 LSA and a 110ICL. For a carburetor setup with the Victor Jr intake manifold I'm quite sure Mike Jones would have changed some things like maybe a 108LSA. Bottom line is the camshaft was not optimized for a carburetor system but did OK.

When things are finalized I will post the chasis dyno RWHP numbers.

those are some great results
i bet your car will shock more than a few LSx owners

one question, are you going to use the carb for the first couple of pulls after the motor is in the car?
i know it would be more work, but i think it would be interesting to see what the difference is between the engine and chassis dyno numbers.

No, I'm going straight to the fuel injection setup. I think my EFI setup flows better than the Victor Jr. I'm having the Victor Jr intake manifold flow tested to see what it does. After looking things over I think the Victor Jr was the intake restriction on the dyno test.

I should have the flow results next week. I believe my EFI setup flows around 320cfm and I'm thinking of toying with it some more. So maybe I will pick up some more power with it. I know I will pickup torque with the longer runners. Things could be very interesting when I get the car on the chasis dyno.

For those interested here is a link to a video of the dyno session put together by Mike one of our club members. He did an outstanding job with the video.

http://www.youtube.com/watch?v=WTT4Jf3CqFQ

i have no doubt that you'll pick up some torque with the EFI intake.
and it would defiantly be good to see some more HP from it.
im looking foward to seeing the numbers.

didn't you say you got some gains from the old motor with the terminator boxes?

something i don't remember you posting about and if you don't mind me asking, what was the fuel mileage like on the old motor?

With the old motor I was getting 21mpg on the highway with 3.70 gears. The exhaust termination boxes will be fitted in with the new motor. I'm hoping to pick up some power here and there.

One will be coating the headers inside and out. This should keep the exhaust gas velocity higher with the heat retention and maybe a couple more hp from the overlap phase. Also we have replaced the oil pressure spring with the one that came with the oil pump. I will also go back to a 5W-30 synthetic oil. That should be worth a few hp from those items.

This week I should have the results from the Victor Jr flow test. That might give me a clue of what to expect from the EFI intake.

Did the dyno use shop mufflers on the headers or was it just dumped as it looks like small S bend then open? Collector length there may be optimal for high rpms which hopefully the boxes can match that

No mufflers were used. Just dumped into the atmosphere and that is what the exhaust termination boxes are supposed to represent. I believe the rest of my exhaust system is free flowing enough as to not provide much of a restiction. Everything, intake, cam and exhaust is supposed to be tuned to 6500 peak horsepower. I will find out when the motor is in the car and on the chasis dyno.

Ok we had the Edelbrock Victor Jr intake manifold flowed that was on my engine at the dyno. Looks like a chance to pick up some more ponies as my First EFI system flows over 300cfm on all cylinders.

wow look at that air distribution difference! Makes me want to have my victor E manifold ported to match. I hope I am not starving those 4/5 cylinders.

Yes, that is quite a discrepancy. According to Dr J, when I opened up the plenum it helped the outside cylinders but not as much on the inside cylinders. It would not hurt to have someone flow your intake manifold to see where you stand. The biggest problem is if one was using nitrous. You want the cylinders to be the same flow wise.

Looking good!!

Yep, gotta be careful on the carbed intakes,, but if the intake was flowed right side up with a carb on it,, bolted on and running through the heads I doubt there would be that kind of flow difference between the runners. Plus intake dynamics on a running engine is no easy task to tackle - even the best teams in the world have to test the intakes on the car to really get a handle on what works.

If you haven't seen this article yet,,, it's worth a read. Note the before and after flow increase on the Air-Gap with the intake flowed upside down and then look at the flow differences between as-cast and ported when flowed through the heads and I'm going to guess with one of the radius entry carb plates. You would have thought HP would have increased more than it did.

http://www.hotrod.com/techarticles/e...ing/index.html

As far as Victor Jr vs your FIRST/SLP intake I'm going to guess you'll drop around 20HP between HP peaks and pick up about 20lb/ft between TQ peaks. However,, you'll probably see a 30+lb/ft torque increase everywhere between 3200 and 4200 rpm. With that 700r4 you will appreciate the torque increase on the street for sure.

Thanks BadSS. Running a built 4L60E now adays. I was hoping with the higher flowing First intake that the horsepower would stay the same or pick up a couple. Just trying to give the cylinders all the air they want. You might very well be right though. My thoughts exactly on the torque pickup with the longer runners. I have read the article about Dr J. When everything is in place and tuned the chasis dyno pull will tell the tale.

With the TCI controller I will have it lock up the torque converter above 50mph for one bonzai pull with the motor cooled down. I will be going to a Yank PT4000 lock-up converter to try and maximize everything for the 1/4 mile. Going to see how close I can get to a 10.99.

One more thought regarding the First intake manifold versus the Victor Jr that I ran on the dyno. I was kind of hoping the First intake manifold would be somewhat on par with the EFI intake manifolds that are run on the LSx 6.0 cars. I think flow wise and total length they are very similiar. If that so that is a good omen. Plus I can't leave out the 3rd harmonic wave tuning I did not get with the Victor Jr. Just trying to rationalize myself into a couple of more horsepower.

Could have made a 401 inch motor

"Could have made a 401 inch motor"

Hehehe. We discussed this the other day. If I was going to build a big inch small block it would be a 427. Has a good ring to it.

Excellent results. Cannot wait to see the chassis dyno & "dragstrip dyno" #'s once it is installed in the car.

i would have to say those are the longest shortie headers i have seen, i would really consider those pretty much longtubes. but good numbers, but i would actually like to see the results with real shortie headers.

From what has been posted on various forums "real" shorty headers perform the same. Above peak torque there is no real difference. Below peak torque the long tube runners have an advantage. "Real" shorty headers have fewer bends so less pumping losses. Most people are trying to kill off the torque as they have to much and are spinning the tires. I would not call these long tube headers by any stretch of the imagination. The average length of the primary tubes are about half of what they would be on a long tube header.

Longtubes - no. Mid lengths... possibly. The design obviously does it's job, I'm impressed to say the least. A good friend of mine has a 95' Mustang GT. When we swapped the BBK equal length shorties for BBK long tubes, the car picked up .25 and 2 MPH. The car was not retuned, pretty much back to back testing a week apart in similar weather conditions. His car has a stock shortblock, mild emissions friendly Crane cam, Edelbrock performer 5.0 heads, and all the bolt on stuff. With lots of tuning on the dyno and at the track, it makes a measly 290 RWHP and 314 RWTQ. But, runs 12.5 - 12.6 @ 3420 lbs race weight. (3420 w/ driver)

I have the top end apart currently, mild bowl porting for the heads, and a newer camshaft from Anderson Ford Motorsport.

1989gtatransam: has dyno don started to consider making more of these custom headers that you have because i would be very intrested since i am suffering from ground clearance with my longtubes right now. i know you said a while back that dyno don was only making one set like that,but i could really use a set like that.

I don't think Don wants to get into that part of the business. To many headaches. I have to have a tubular K-member for all this to fit. Anyways I think his standard headers will do the trick. Remember these were made up in order to fit in my exhaust termination boxes.

This is not the only time results like these have been posted. Joe Sherman as an example has seen all types of headers tried out on his engine dyno over the years and has come to the same conclusion. Above peak torque there is really no difference between long and short tube headers considering they are both of equal quality.

Its funny how the LSx guys swear by longtubes, they always talk down those who are considering shortys. Its results like these that need more exposure. I do agree a proper shorty header should still hang with longtubes with power/torque production.

"Its funny how the LSx guys swear by longtubes"

I know. I have stopped trying to present another point of view. I will just let the internet lore continue. It is interesting how good the latest Corvette headers flow and they are short tube. I saw a test where they were swapped out with long tubes and there was hardly any gain at all.

As the saying goes you can lead a horse to water.....

Either way i went with Longtubes on my 99 trans am because you cant beat 311 bucks for the pacesetter headers and 140 for y pipe. Shortys are not a bad alternative tho

I just wanted to lay to rest the internet lore that shorty headers are only a little better than log manifolds and not worth putting on and one should go straight to long tubes. Clearly not the case as has been proven in this test and others. I might add there is certainly nothing wrong with long tube headers performance wise and I don't want to imply so.

I can't wait for the Los Angeles Invasion this year against the 4th gens while running TPI and short tube headers. I think our 3rd gen club will surprise a lot of them this year. We should have a number of low 12 second cars and some running in the 11's. They will be looking for the NOS. Hahahaha.

Extraordinary info!
That's the kind of real world data that we need to see.
It's interesting in the photos to see the length of the collectors on the "long tubes" vs the length of the collectors on Dyno Don's headers. Does this correlate to the results of the Pipe Max program? I never would have expected the values to be so similar. Might this be the different harmonics at work here?
If your termination box calculations are accurate then you'll achieve open header performance with a full exhaust as we've been discussing for over a year.
All the nay sayers will eat your dust.
Truly well done.

Yes the header collectors were built to PipeMax's specifications. My collector diameter is 2.75" which PipeMax says to use for the shorties in this case. For long tubes PipeMax says to use a 3.00" diameter and that is what the long tubes were in this test.

I would assume that includes collector length as well.
Based on your info, I can see the direction of this winters project. It's only a little 350 however I'm determined to get the most out the combination and that includes the same attention to the exhaust as you've applied. As I'm set on the intake and heads, the only other area of improvement will be cold air and no restiction in the air filtration.
Again, I'll say "Job well done."

I do agree with some above comments regarding your "shorties". They do seem to be more "midlength" than a typical block hugger shorty you see with hooker/hedman/etc for our cars.

Either way I would venture to say not much would be lost if you did go abit shorter with the primary length but kept diameter the same

Yes, collector length as well. Yes, the primaries are longer than Don's shorties on average but these have more bends.