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I just wanted to display how good these afr 195 heads are. I purchased them last fall. Finally this spring I got to use them and race my car.
I have a mild 385 sbc eith a xr288hr cam, victor jr intake, 750 carb, 4.10 gear, ptc 5k stall. All motor and a 3400lbs race weight street strip camaro.
Right out of the Box these heads where beautiful the craftsmanship was amazing, they looked like you would want to display them on the wall. Bolt up was easy, and customer support was perfect.
I made 3 passes so far with the heads with a best of a 10.73@125mph. 1.48 60 foot.
I purchase these from summit racing but I highly recommend them for anybody with a mild small block Chevy. I never thought I would go this fast with A 195 head.
has Doug's long tube 1 3/4 headers and dual 2 1/2 inch collectors and cut outs right now. No mufflers. Loud on the road... I have race mufflers to toss on still
Have the 288 in my 355. Idle vacuum is about 12" with vacuum advance on manifold and about 28° of idle timing. And with a lean cruise tune I can manage better than 20 mpg on the highway. So you can be fast and economical if you really want to be...
Well done Eddi. I've always liked your car. Something mine will eventually morph into as I get away from mostly street to being mostly strip.
has Doug's long tube 1 3/4 headers and dual 2 1/2 inch collectors and cut outs right now. No mufflers. Loud on the road... I have race mufflers to toss on still
Don't forget to address the correct tuned collector length. There's power and torque left on the table if you disregard it's impact.
How far past the header flange are your cutouts?
One of the best street strip bolton ready heads out imo. Price has gone up over the yrs but most things have anyway. They just make power tho
Your setup is really moving good for the parts. I had slightly smaller duration cam but more lift in my 383 with afr 195’s. It went 11.47 at 118 with best of 119 mph in summer air. Stealth ram intake. Wasnt as racey tho with just 3.42 gears and 3600 stall
Have the 288 in my 355. Idle vacuum is about 12" with vacuum advance on manifold and about 28° of idle timing. And with a lean cruise tune I can manage better than 20 mpg on the highway. So you can be fast and economical if you really want to be...
Well done Eddi. I've always liked your car. Something mine will eventually morph into as I get away from mostly street to being mostly strip.
Even at 16° timing at idle, I'm barely pulling 12" with my 276HR at a reasonable idle speed. Makes me wonder.
Don't forget to address the correct tuned collector length. There's power and torque left on the table if you disregard it's impact.
How far past the header flange are your cutouts?
The cutouts are 14 inches past the header collector. I'm not positive if that's long enough as I've heard a lot of ideas about collector length.
One of the best street strip bolton ready heads out imo. Price has gone up over the yrs but most things have anyway. They just make power tho
Your setup is really moving good for the parts. I had slightly smaller duration cam but more lift in my 383 with afr 195’s. It went 11.47 at 118 with best of 119 mph in summer air. Stealth ram intake. Wasnt as racey tho with just 3.42 gears and 3600 stall
I agree they are the best outta box sbc head for street strip cars. I was quite surprised how fast my combo is going as well. I was expecting 11.20s or a bit under. Never did I expect 10.70s. Even though it is a track set up.. the mph shows how much hp its pushing which amazes me.
But keep in mind I ran 11.60s@115mph last year with ease and it was a very mild set up. Xe268 can, 3.23 gear, 3500 stall, old as cast 200cc dart iron heads. I was shifting at 5200 and trapping about 5000rpm. So my car must be set up pretty well.
Even at 16° timing at idle, I'm barely pulling 12" with my 276HR at a reasonable idle speed. Makes me wonder.
A little more timing will bump the idle vacuum up. I had about 14" of vacuum with the XR276HR.
Idle speed with the 288 is about 800-850. With the 276, I managed a lower idle speed of around 750.
I have the base timing set at 16° and my vacuum advance is all in at 8-9" vacuum which adds another 12-14° depending on my tune.
The cutouts are 14 inches past the header collector. I'm not positive if that's long enough as I've heard a lot of ideas about collector length.
Thats not to bad to be honest
14 plus length of collector would be around 21-22” i guess? Depending what rpm you tune for, thats getting close to the “bad” length and just past ideal
Ideal likely would be 17-18 from end of primary tubes to atmosphere cutout
Might like 3” collectors too
I haven't run PipeMax for a 383 so my 355 results won't necessarily be what's best but lengths are 19.3 and 38.5 for best torque. Best HP is 19.3 and 9.5".
This is for a members engine here at Thirdgen and was spec'd with a short style header. I'll look to see if I don't have an archived 383 file buried somewhere.
A member here (loopy) has that as part of his build. Not my choice but I ran the Pipemax for him to see what the results were.
If fasteddi posts enough engine information, I could probably run it through the program.
14 plus length of collector would be around 21-22” i guess? Depending what rpm you tune for, thats getting close to the “bad” length and just past ideal
Ideal likely would be 17-18 from end of primary tubes to atmosphere cutout
Might like 3” collectors too
Best lengths are 16-18” or 33-35”
14 inches is from the collector flange to the cut out inlet flange itself. Its a short amount but just long enough that my widebands work good
Last year I went from hooker shortie headers 1 5/8 into the y pipe and 18 inches to a open cutout to these Doug long tube 1 3/4 headers and the exhaust I have now... went from running 11.90s@110mph to running 11.60s@115mph just like that did nothing else. Amazing if you ask me.
Last year I went from hooker shortie headers 1 5/8 into the y pipe and 18 inches to a open cutout to these Doug long tube 1 3/4 headers and the exhaust I have now... went from running 11.90s@110mph to running 11.60s@115mph just like that did nothing else. Amazing if you ask me.
There may be more too depending on how close you are to optimum now. It's crazy how a few inches one way or another can make or break a combination.
I go back to the times when my headers were freshly installed and the car had to be "delivered" to the exhaust shop. Driving around, the headers open and nothing more than maybe a 6" long collector (primary tips to flange) and the engine was complete slug low in the RPM range.
Post your specs as per below and I'll run it through for you. (If you're so inclined).
Originally Posted by fasteddi
... went from running 11.90s@110mph to running 11.60s@115mph just like that did nothing else. Amazing if you ask me.
THAT is exactly the kind of result I'm hoping for once I get to that point. The single full length 3" exhaust is absolutely killing performance. A simple set of cutouts would be all that's needed to add similar improvements as you've had.
There may be more too depending on how close you are to optimum now. It's crazy how a few inches one way or another can make or break a combination.
I go back to the times when my headers were freshly installed and the car had to be "delivered" to the exhaust shop. Driving around, the headers open and nothing more than maybe a 6" long collector (primary tips to flange) and the engine was complete slug low in the RPM range.
Post your specs as per below and I'll run it through for you. (If you're so inclined).
THAT is exactly the kind of result I'm hoping for once I get to that point. The single full length 3" exhaust is absolutely killing performance. A simple set of cutouts would be all that's needed to add similar improvements as you've had.
what specs do ya need? You mean all the engine ones?
385 sbc 4.040 bore. 3.75 stroke. P2d .012 head gasket .027, quench .039, +5cc flat top pistons with 2 reliefs. Afr 195 heads 218 cfm exhaust 280cfm intake@.550 lift comp xr288hr cam. 288/294 adv. Duration. 236/242 dur at. 050. .555/.576 lift with 1.6 rocker. 110 lsa installed at 106 centerline. 11.0:1 compression, victor jr intake 2999 version which has 1 inch taller adapter built in, holley 750 carb with proform main body, double pumper mech. 2nds.
A few questions.
Rod length?
Peak HP RPM?
If you have the valve sizes and stem diameter that'd be handy. Otherwise I'll look up stock AFR Eliminator specs (street version).
A few questions.
Rod length?
Peak HP RPM?
If you have the valve sizes and stem diameter that'd be handy. Otherwise I'll look up stock AFR Eliminator specs 6500(street version).
5.75 rod 2.05 Intake valve. 8mm stem. Thanks man those charts are nice
Dropping peak HP RPM down to 6000 stretches the collector to 18.6".
Considering the worst case is about 28" there's some margin for a good result even if you're off by a couple of inches.
05-18-2018, 10:22 AM
