Changing Intake and headers....HP increas??

[eric n]

So I now find myself thinking about changing intake and headers to increase hp. Currently I'm running a performer rpm intake and mustangs plus tri-ys with my combination listed below. I'm thinking about switching to SUPER COMP headers and a VICTOR JR intake. I wondering if these are more sever than I would really benefit from. I don't see twisting the thing over 6500 rpms and I don't want to loose too much tq down low.

Should I consider other components? I'm currently getting 272 hp and 292# or torque at my rear tires. I'm really wanting to get into the 290+ range.

 

[allcarfan]

dont know what pistons you have.....but with some 1 3/4" headers, and an xe266 cam....SAME COBINATION as you have listed above made 396hp and about 375 ft lbs of torque at the fly wheel. With an xe274hr cam...you would be making about 375 to the wheels.....wait...is this a roller setup?

id say NO to the vic jr. its going to be way too much for your setup. You can notch your performer RPM and get the performance of a single plane intake and take advantage of the longer runners. Just a thought.

 

[Edbert]

Eric, without knowing more about your cam it is hard to say for sure but I'd tend to agree with allcarfan. Those Victor intakes require pretty healthy breathing to work right, and on most motors this means much more than just good headers (which the supercomps certainly are). You've got a good starting point with those heads, but the Victor is stout and with a moderate cam those heads may need some porting. I chose the Perf-RPM myself for a better idle, more torque and more vacuum.

 

[12sec67]

375 at the wheels?

 

[eric n]

PISTONS are JE forged 9.5 / 1 compression

Cam specs are: 292 intake/302 exhaust duration, hydraulic, cam

You guys are pretty much verifying my instinct that the Victor Jr gets it's power way way up the power band for what I'm doing, but that the SuperComps would be a nice addition.

Question about the headers. I know that the ceramic coating runs about 180 bringing total price to around 500. Other than the wow effect does the ceramic coating have a lot of real value. I know it's suppose to lower the engine compartment temp considerably. How does that translate to operating engine temp? Will I see a differance of 10, 15, 20 or more degrees???? Or should I just get the Super comps with no ceramic coating???

Appreciate the intel. If I had known about stang net earlier I likely wouldn't have to RE DO all of this crap.

 

[allcarfan]

12sec67...

The 302 that i was talking about was standard bore, box stock TW heads, an xe266hr cam, 750 speed demon, 1 5/8" headers, and a performer RPM intake....made 396 hp at the fly wheel. The combo NEEDED larger headers and the 750 speed demon was too big. Accounting for a 20% loss of HP through the drivetrain (and 20% is a VERY generous loss) 400 at the flywheel equates to 320 or so at the wheels.

A 306 with tw heads an x3274hr (or even an xe282hr) cam, portmatched intake/heads, a 650 speed demon, a 1 3/4" headers...would EASILY add/free up anoter 50-75 HP. So, that puts us at 450-475 at the flywheel. Accounting again a 20% loss (remember most cars dont lose that much) we are looking at 360-370 at the wheels. These are dyno-proven numbers, not magazine numbers.

EricN...

I dont think the coated headers will lower your engine temp at all. They will, however, lower underhood temps drastically. The next time I get headers, they will be ceramic coated....INSIDE AND OUT!!!! Coating the insides will let the exterior coating stay on much longer because it wont burn off as easy. Bikers do this with their chrome pipes so they dont 'blue'

 

[ratio411]

The headers will help you IMO.
The intake is too much.
You do need a single plane IMO, but a single plane much milder than the Victor.
Look for something like the Wieand X-Cellerater, Offy Port-o-Sonic, Holley Strip Dominator, or Edelbrock Torker 289. (Not Torker 2)
These intakes have runners and plenums tuned for streetable rpms and good throttle response.
I don't see a problem with you reaching your goal with better headers and intake.
Good luck
Dave

 

[ratio411]

The 302 that i was talking about was standard bore, box stock TW heads, an xe266hr cam, 750 speed demon, 1 5/8" headers, and a performer RPM intake....made 396 hp at the fly wheel. The combo NEEDED larger headers and the 750 speed demon was too big. Accounting for a 20% loss of HP through the drivetrain (and 20% is a VERY generous loss) 400 at the flywheel equates to 320 or so at the wheels.

A 306 with tw heads an x3274hr (or even an xe282hr) cam, portmatched intake/heads, a 650 speed demon, a 1 3/4" headers...would EASILY add/free up anoter 50-75 HP. So, that puts us at 450-475 at the flywheel. Accounting again a 20% loss (remember most cars dont lose that much) we are looking at 360-370 at the wheels. These are dyno-proven numbers, not magazine numbers.

When you are dealing with an engine as small as 306, you are being very optimistic that a cam and header change will add 50-75 hp. Every hp gained on a N/A engine after 1hp per cube becomes increasingly difficult to obtain. If you think about it, much more drastic changes offer less hp gain, IMO if we were dicussing a 400+ cubic engine, 50 hp would not be as much of a stretch.
I might be wrong, but I am very uneasy with that assesment in your post.
My .02
Dave

 

[allcarfan]

im sorry that you are uneasy in my assessment of a dyno-proven combo

 

[GaPonyFarm]

The FIRST thing I'd recommend is get it on a dynojet dyno and make sure its tuned properly. Get the timing and A/F ratio correct across the range will do wonders.

Don't buy anything until you've done the dyno tune. Once you've done that you'll have a clearer picture of what can help. Be sure to ask the dyno guy for recommendations, those guys see lots of setups and are usually pretty knowledgeable.

 

[eric n]

The FIRST thing I'd recommend is get it on a dynojet dyno and make sure its tuned properly. Get the timing and A/F ratio correct across the range will do wonders.

Don't buy anything until you've done the dyno tune. Once you've done that you'll have a clearer picture of what can help. Be sure to ask the dyno guy for recommendations, those guys see lots of setups and are usually pretty knowledgeable.

THANKS, It's been on the dyno several times from 207 hp to the current 272. It's a great motivator, my recent (2 weeks) move to the BG Speed Demon was dyno motivated. As this interest in Super Comp Headers (which have gotten almost universal support here on the boards) My current goal is to get to around 300 hp and then take it to the strip and start the real learning curve. I'd love to be Close to 12.9. I think my tranny and traction issues will be my next issue. Again thanks for the help.

 

[ratio411]

im sorry that you are uneasy in my assessment of a dyno-proven combo

The first paragraph you quote dyno figures, I was not clear that you dynoed the combo with cam, header, carb changes that you discribe in the second paragraph.
The way you worded it, you were supposing a 50-75 hp increase with the mods. I misunderstood.

I still think, even with dyno proof, that some other factor was involved. Without seeing the dyno, it is hard to tell.
Going from cast iron log manifolds to LT headers is only worth 30 FWHP, and going from cast iron 2v intake to Performer RPM/650 cfm is good for 15 FWHP. Stock cam to moderate hydraulic after these mods gains about 10.
I only put this info forth so you can see how I am dubious about adding a little primary size, a little duration, and changing carb size 100 cfm would equate to more power increase than the previous giant leap forward from stock.
Tuning was off or more changes were made than mentioned for your 2 dynos to be so different with such a small engine, IMO of course.
Dave

 

[eric n]

The first paragraph you quote dyno figures, I was not clear that you dynoed the combo with cam, header, carb changes that you discribe in the second paragraph.
The way you worded it, you were supposing a 50-75 hp increase with the mods. I misunderstood.

I still think, even with dyno proof, that some other factor was involved. Without seeing the dyno, it is hard to tell.
Going from cast iron log manifolds to LT headers is only worth 30 FWHP, and going from cast iron 2v intake to Performer RPM/650 cfm is good for 15 FWHP. Stock cam to moderate hydraulic after these mods gains about 10.
I only put this info forth so you can see how I am dubious about adding a little primary size, a little duration, and changing carb size 100 cfm would equate to more power increase than the previous giant leap forward from stock.
Tuning was off or more changes were made than mentioned for your 2 dynos to be so different with such a small engine, IMO of course.
Dave

The car was first dyno'd with tri y headers, heads that were suppose to be ported and polished with increased valve size looked pretty damn stock when taken off, Com Cams magnum roller rockers, a pretty mild isky cam, Holley 750 with vac secondaires (7160), Performer intake, JE 9 1/2 to one pistons, MSD ignition.... The initial dyno results were disappointing to say the least (207 if I remember and I've tried like hell to block it) as the guy who built then engine was talking wild wild numbers and charged me a grip.

At the recommendation of my dyno shop I changed the heads to twisted wedges and changed out the cam to the more aggressive Summit cam I'm running now. During that same time I had a Auburn pro unit and 3:70's added to my 9 inch (eats a little rwhp). After some tuning I was able to get up to around 250 rwhp (still really disappointed) Just now I have added the BG Speed Demon which has me at 272 (still disappointed but not embarassed) without going through reciepts, that's about what has happened. Others with similar combos are in the 300 range

The BG was actually 100cfm smaller than I was running before, but the Holley 7160 was a freakin DOG, though ok for gas milage. I'm sure a Double pumper or 7150 would have been a better choice.

It seems everyone is in agreement that headers like the Super Comps would be a beneficial change, so obviously I'll be doing that in the next month. I'm also going to get a new driveshaft in as the change to 3:70's has brought about more vibration at anything over 85 mph. After these changes we'll dyno again and see where we are at. WISH ME LUCK.