Guys im curious if anyone has done dyno testing with headers and what the power gains have been . Atleast with an olds. I see headers available in 1 5/8 , 1 3/4 and 1 7/8 and I wanna say 2 inch as well.

The reason I say this is because im not making any major changes to my car this year but im thinking of little things that might help. I have been running some Dynomax headers for years. 1 3/4 primaries. IM curious if going up to a 1 7/8 primaries would help . I have never actually bought new headers I just buy peoples old stuff so I think if im gonna buy new I wanna buy something that might make more power if its even a worthy investment at this point for me. My headers are nice ceramic , coated and the flanges are not beat up so there really isn't any need to upgrade but if I can make some power then why not.

 

Here is my take on subject. Too much air flow boggs engine. Too much air coming out with not enough back pressure also not good. Hp on engine to my thinking determines what size headers. I have gone from 17/8 to 2" no gains. Unless you have lots of hp in a small block i would think 1 7 /8 is too much. But hey I have no proof no facts.

 

The reason this thought peaked my interest is because my open x pipe held back the engine almost 2 tenths vs. Just open headers but... It was a 2.5 inch x pipe. The exhaust holds.it back almost 5 tenth. 12.35 vs an 11.91 on that particular day if testing. Best pass with open x pipe was 12.15 best pass open headers was 11.85. Im wondering if up top my headers are a bit restrictive. Im spinning this engine to 7k Rpm.

 

You’re not making enough hp to warrant 1 7/8 headers. I’d play with collectors before I changed headers.

 

Ok now here is a question say we set up the extensions and they come in at say.... 14 inches for what works best. If I have cut outs do I factor in part of the collector extensions into the length of the cut outs ??? or do I install them after that. AS it is I have about 12 inches past the collector which is about where they usually work well from what I have read.

 

Look into a website from a man by the name of Calvin Elston. You’ll learn a lot.

 

I would also play with collector design or just collector tube length.
Quality headers make HP/TQ
Class racer is also a good place to look their are some very good threads on the topic. They use all kinds of header design, Step Headers,TRY y Headers, True equal length Headers. spike collectors etc..
What I found interesting was that to make a header work to its full potential a custom cam might be required.
I'm not saying to invest in any of these Headers just take a look at the gains that can be made when going to the extreme.
What works for one engine might not work for another, some see small to no gain at all, other see large gains.
You might want to try a set of hooker headers, good used would be my suggestion.
Hooker headers might not be the ultimate header but bang for the dollar best value in headers in my opinion.
Warning You may are may not see a gain with the hooker headers as there are no guaranties.
Good luck
I like the fact that you are always looking to improve your car with in a budget.

 

A good header with collector will build bottom end torque, where as zoomies will be for high rpm Hp. Most class racers use stepped headers to get something between the two.

Ray

 

I have a cheap set of black jacks up in the rafters ( My old headers ) and I was thinking of trying those flowmaster collectors. But I don't think they make em anymore. Some claimed gains some no change. The 2.5 in. exhaust was restrictive so I think my open X pipe passes are a bit inconclusive but I also want to try a 3 inch open x pipe. My old combination made more power with the open x pipe. I think for this combo the 2.5 inch is just too restrictive even with the open x pipe., so all my current passes have been made on open headers.

 

Good advice.

 

Yep I pretty much agree, and most advantages are more to do with the collector end on headers. And even on the full exhaust system, larger doesn't usually call the tune on that dance either.

 

You can also try running your combo through Pipemax to see what it recommends for headers.

 

Unfortunately the heads where never flowed although a similar set with bigger valves was (67cutlassfreak) did them those figures would make the pipe max figures a pipe dream. If I find a cheap set of headers im willing to do the track test. Same goes for the collectors simple enough .

 

If seeking power/speed I have always used timers and a/b testing.

 

Huh?
You should’ve flowed them. Information is good.

 

Firewalker we spend lots of our weekends at the track lol. That's how I plan on seeing if an experiment will make power. @ Mark we opted to not flow the heads because I didnt see it as a fit investment. I know data is everything but too late for that. I have to talk to Dave he has the flow numbers to a similar set of heads to mine. The only difference is it had bigger valves. I know the bigger vlaves improve the flow so i know that would provide inconclusive data for my useace atleast. Thats what I meant by that lol. Keep in mind this engine morphed over almost 6 years the heads sat for like 5 years at the time they where done I couldn't afford a set of valves . knowing what I know now. I would have had then flowed but funds where very limited when all that happened.

 

I said it before and I'll say it again "The reason you get your heads flowed is NOT to see how well you or someone else ported your heads but, to know how much air they can flow. The reason for this is so you don’t pull your hair out or waste a ton of money uselessly trying to get the car to go faster. The amount of air they flow dictates how much Hp the engine is ALLOWED to make." For example my "G" heads flow 232 CFM at 28" H2O which means the maximum Hp my engine can make is 440 at the crank or 335 at the rear wheels, nothing and I mean nothing I can do short of porting them can I make more Hp, unless I use a power adder. On my 455 I use 1-3/4" Black Jack headers. Pipe Max says 1-3/4 is best for my engine. Going by my car weight, mph, and ET. my car makes 323 RW/Hp.
For rear wheel try this site www.1728.org/mtrair.htm
For crank Hp try this site www.wallaceracing.com

Ray

 

I have had one just like this, since the mid 80s and used it religiously. This way any time and anywhere when its safe I can test and tune. And without everyone and their dog knowing.

https://www.ebay.com/itm/Vintage-80s...sAAOSw3CdcW5Ib

 

Mark, I’ve never heard of this guy before. He is an incredible wealth of knowledge on header design and is good enough to share it. Most of it is over my head but I know a couple of the guys that asked him questions, used to drag race with them.

 

74sprint . Well aware the point of a flow test., there is also other things you want to look for in a flow test that help build the engine. But That's not the point of this post. I am not looking for "how much HP" will I make but rather is the bang for the buck there based off of others experiences. The calculator may say you need X amount of inches for diameter on the primaries but you still have other variables that could affect the velocity. You might make peak power with a 1 and 3/4 but if the engine revs slow because its in a heavy car that's under geared I can see that as a the slow turning RPMS killing velocity on its way to peak HP . That's where theoretical calculations have to intersect with real world scenarios.

 

Whats your car run?
MPH
Known weight
Track

I just used the above Wallace calculator for CFM to HP, seems to be close to what I see on the dyno.

 

A correlation would be the super flowing Victor intake with its larger intake ports, that slowed down some very already fast cars by 1/10s..

 

IMO your doing just fine, your not spending money and getting good results, infact much better results than the local engine builder on here..........carry on.

 

IM intrigued by the 4-2-1 header design and somewhat understand the theory and the pit falls. I also want to try a merge collector . I have a spare set of headers and can use teathers. IF i get the gumption and can find some merge collectors at the swap meet in the correct size ( which they do usually pop up) im willing to cut up my old headers. The 4-2-1 headers are simple enough to make . Those are the 2 designs I want to try. It seem the 4-2-1 headers are ideal on lower HP set ups from what I have read but can kill HP on the top end depending on cam design.

 

I'd be looking at the trans and converter, but again I'd be looking for tenths not hundredths.

 

I know I need a better converter and a some more gear wouldn't hurt. Im shifting at 7k and hitting the stripe at 6k

 

I agree, an here is Dwight Kohout who spent little, and used the wrong cam heads, and the rest, and runs at least low low 12s.

http://www.dragtimes.com/Oldsmobile-...slip-9738.html

 

I am actually building a J headed 455 destined for the Pontiac im setting up for my wife to race and drive . lol. I remember seeing Dwight's car back when I was 18 at the Byron BOP and thinking it was such a cool car because I had never seen a G body with a body kit . I had just bought my cutlass that summer. I wanna say it was 2007 . My mentor in my trade runs with the rocket racing guys and I got introduced to the olds racing world that day. Sorry to get off subject but that brought back some good memories.

 

Hey its your thread, but time is flying just way to fast, for him and us. But if you are going to get an introdution to cars, to be impressed with, his I think is among the best. He also knows more than a little bit about headers, if you can run him down.

 

3850 lbs. 12.74 sec. 110 mph best 60ft 1.65

Ray

 

I agree wholeheartedly, even dynoing an engine does not simulate a car going down the track but, it is a good starting point. Hey you gotta give it what it wants. Also I probably would have won more races if I would quit playing around with the car trying different things, oh well it's fun to me. The new track operator has test & tune almost every Saturday now, I go whenever I can. So are you going for more torque or more Hp ?

Ray

 

I like to get a glimpse of what the high dollar nascar racers are doing. Sometimes crash footage reveals extensive exhaust work. Brake, suspension, plumbing and other ideas.

 

Hi,

Yeah but remember NASCAR and other racing forums do things for other reasons than HP, more aerodynamics and drag at the speeds they normally race at.

Regards,

 

I was surprised to find spike header collector design being promoted in a 1978 basic hot rodding book. They also went into header tube length, diameter and that bigger is not always better.
The headers that are sold at Summit and Jegs are a compromise between production cost, fitment, etc