You mean Denny's massive effort in particular? Or is that just a general comment on the thousands of other grown men spending huge amounts of money and time trying to make our cars go faster?

 

Going to do a dyno session latter this morning if time available as I'm not sure what was done prior was valid because of the headers. Basically found by accident the headers were hitting the motor mounts under hard torque and that was causing a header leak only under torque possibly throwing off the tune and the results.

The sheetmetal intake did show quite a bit of bottom end gain which at the time I associated with the longer intake runners. Now I'm not so sure. Hopefully the dyno will be open and I'll get a better look at what the intake really does.

Thinking also about removing the intake and regooping it with a bunch of silicone to make sure there are no possible leaks also.

 

Denny
If ya get the Burns headers please let me know the results.

 

What kinda price does Burns want for a set of headers?
Ever think about Lemmons?

 

Hell, I was hoping you'd tell me.

Really like to see someone else's results before I leaped this time as I don't mind putting in the time and money as it's a hobby, but sometimes you like to see progress, just not wasted effort chasing for magic bean stalks.

Based upon the spec sheet sent in to Burns they recommended a 1 3/4ths, to 1 7/8th's to 2" pipe in equal lengths going into a 3 ½" megaphone collector but wouldn't give exact details on the taper or length of megaphone collector. Which is fair, being they did all the design work and I've not paid them anything.

Right now, back to where I was 8 months ago to see what's up with the intake.

 

Burns sells ya the pieces then you got to have them welded locally so I'm not sure exactly what it would cost. Basically all options are on the table including Lemmons as I've just returned from the dyno and unbelievable as it seems, one of my Hookers apprears to be leaking plus my valve spring @ higher rpm issue has reappeared so it was a wasted session.

We'll figure out something.

 

Neither. Just the stepped headers.

 

Denny,
They are 1500.00 for the kit and collectors and the prices I got to build a set were in th 14/1500.00 range.
The spects they gave you are the same they gave me for a 383.

Wish I could tell ya.

 

Just another data point. A friend of mine has a 441 SBC with ported 230 cc heads and a big 26x/27x solid roller. It made 690 hp on an engine dyno and somewhere around 530 - 540 on a chassis dyno with Hooker 1 3/4 LT headers. He swapped to a set of Hedman 1 7/8" headers with "flat" collectors and and picked up basically no hp, but a about 30 ft-lb down low.

Strange thing is a while back, one of my other friends had a 355 LT4 combo with a cc306 and shorties. He swapped to a set of 1 3/4" Hooker LT's and it also gained basically no hp, but about 30 ft-lb down low.

Mike

 

I justed ordered some Hedman 1 7/8's, sold my stepped Kooks. Most cam companies or specialist I spoke w/ rec. the bigger primary header.

 

This is all very interesting to compare real world notes of what others are actually running into. Guess my question is why did the people you talked you recommend a larger primary vs stepped and what did they say could expect?

Also please do post your results after you've installed them to see if the results meet the recommendations.

 

Guess I should tell the entire story first...I'm planning on pulling to 7500+ with, at most, a 400 shot. I didn't go into great detail with them on their thoughts of the larger primary, just assumed it had to do with the use of nitrous. I bought Jimlab's old RR heads and Hogans intake setup a few years back, it's now time to optimize it all. If I can do it half as well as you I'll be tearing up the 1/4 mile

I still have one set of Kooks with emmisions fittings, guess I could do a back to back swap of headers and see what the results are. I'll be playing with collector lengths on my Hedmans too. If there's noticable gains I may try a custom header from the likes of Burns or Lemmons.

 

-Stock LT-1 block 4.030" bore 11.8 CR
-Callies 3.875" stroke
-Manley billet 6.00" rods
-Canton oil pan

-FMS\Meaux stage 2 AFR rasied runner LT-4 heads( 2.100"\1.60" valves)
-Edelbrock Super Victor carb intake
-FMS solid roller cam 271\283-112 .704"\.688" cam
-Kooks 1-3\4" to 1-7\8" headers( TOO small )

Flow numbers:
IN EX
.200 136.0 99.0
.300 197.1 166.5
.400 253.9 196.4
.450 275.2
.500 291.7 215.6
.550 307.5
.600 315.4 221.1
.650 318.4
.700 324.2 231.6
.750 328.1
.800 334.6 233.7

Copy/pasted from LS1, but very similar setup and Futral seems to think the same about the headers.

 

Here's a little more Info
Flow Numbers 4.000 Bore Fixture No-Pipe
50 degree seat angles
Lift---Int---Exh----E/I Ratio
.200--136.0--99.0---72.8
.300--197.1--166.5--84.5
.400--253.9--196.4--77.3
.450--275.2
.500--291.7--215.6--73.9
.550--307.5
.600--315.4--221.1--70.1
.650--315.4
.700--319.3--226.2--70.8
.750--323.3
.800--327.2--226.2--69.1

Alan Futral - Terry Williams
4.030 x 3.875 = 395.424 CID
AFR alum LT4 Heads 2.100/1.600 valves
Chris ProSystems 1300 CFM
Edelbrock Super Victor w/Moroso 2 inch Adapter
ATI serpentine balancer
11.8:1 CR
MSD distributor
CM solid roller 271/282-112 on 108CL .704/.688
1 3/4 x 1 7/8 Headers x 32 inches KOOKS 3.500x 7.000
6.000 Manley rods Diamond Pistons Callies Crank
Canton Steel Pan Castrol 10/40 5 qts.
-----------------------------------------------------------------------

this is with Stock length Collector

 

this is AFTER using PipeMax to determine correct Collector Length