need help on selecting the right heads for my weak 383(help)
#16
Re: need help on selecting the right heads for my weak 383(help)
I trap a 3750 # car with my 383 at 115.4 mph. thats a little over 400 rwhp. My heads flowed in the high 270 to low 280 range intake and 210 cfm @ .550 lift. I would go with the 210 AFRs and have them ported , youre looking at a good 3 grand, but well worth it. I went with 190 AFRs because at the time I had a 355. When I built the 383 at first the heads were completely untouched and flowed hihg 260s int. A little massaging and some valve work by my machinist gave them 20 cfm , but the important flow is from 200 to 500 where the valve spends most of its time.
The extra volume will also help your motor out. It wouldnt hurt to add a little compression if you cand stand it as well.
The extra volume will also help your motor out. It wouldnt hurt to add a little compression if you cand stand it as well.
#17
Re: need help on selecting the right heads for my weak 383(help)
[QUOTE=regorih inHous.]But the car has slp shorties with 1 3/4 and 2 and half inch. y-pipe with 3in borla. QUOTE]
Im willing to bet there is a lot of HP being robbed with this exhaust setup. Even on a stock headed car with a small cam, a 3in. Ypipe with 3in. exhaust will help a lot. Also, the 1 3/4in. SLP headers are nice but I do feel that you would see bigger gains with a 1 3/4in. LT. With my car I went from BBK shorties/3in. y pipe, and 3in. catback to Pacesetter 1 3/4in. LTs, 3in. catless Y pipe, and the hooker 3in. catback. I gained nearly 2-3mph and 2-3 tenths in the quarter mile. Thats about 20-30hp gain with just different headers exhaust, and Im only running a little hotcam with stock heads.
Aaron
Im willing to bet there is a lot of HP being robbed with this exhaust setup. Even on a stock headed car with a small cam, a 3in. Ypipe with 3in. exhaust will help a lot. Also, the 1 3/4in. SLP headers are nice but I do feel that you would see bigger gains with a 1 3/4in. LT. With my car I went from BBK shorties/3in. y pipe, and 3in. catback to Pacesetter 1 3/4in. LTs, 3in. catless Y pipe, and the hooker 3in. catback. I gained nearly 2-3mph and 2-3 tenths in the quarter mile. Thats about 20-30hp gain with just different headers exhaust, and Im only running a little hotcam with stock heads.
Aaron
#18
Re: need help on selecting the right heads for my weak 383(help)
wow thats a lot! so new exhaust should realy help me out huuu.. hey did you have any clearance problems withe the pace setter header?
#19
Re: need help on selecting the right heads for my weak 383(help)
Originally Posted by 94 CAMRO Z28
Im willing to bet there is a lot of HP being robbed with this exhaust setup. Even on a stock headed car with a small cam, a 3in. Ypipe with 3in. exhaust will help a lot. Also, the 1 3/4in. SLP headers are nice but I do feel that you would see bigger gains with a 1 3/4in. LT. With my car I went from BBK shorties/3in. y pipe, and 3in. catback to Pacesetter 1 3/4in. LTs, 3in. catless Y pipe, and the hooker 3in. catback. I gained nearly 2-3mph and 2-3 tenths in the quarter mile. Thats about 20-30hp gain with just different headers exhaust, and Im only running a little hotcam with stock heads.
#21
Re: need help on selecting the right heads for my weak 383(help)
Originally Posted by regorih inHous.
the car is tuned
#22
Re: need help on selecting the right heads for my weak 383(help)
I think your exhaust is fine. I'm running LPE 1 3/4" shorties, Random 3" Y, and a Borla with no plate and I make plenty of power. Going from a 1 5/8" shorty to a 1 3/4" LT is a different story. I think most of your issues are with your heads, specifically your stock valve size...You are getting and are going to continue to get tons of advice...My .02 is to call several head/cam companies and reputable engine builders. Let the experts lend a hand. Lingenfelter, Lloyd Elliott, Joe Overton, etc...
John Lingenfelter once told me that "its all in the details"...
--Alan
John Lingenfelter once told me that "its all in the details"...
--Alan
#23
Re: need help on selecting the right heads for my weak 383(help)
Lingenfelter had skills, that's a sweet engine he build for you aba383.
To make the power your hoping for I would look into bret's custom intake manifold. If it performs as well as he says it does it should put you damn near your goal w/ a matched head/cam package.
-brandon
To make the power your hoping for I would look into bret's custom intake manifold. If it performs as well as he says it does it should put you damn near your goal w/ a matched head/cam package.
-brandon
#25
Re: need help on selecting the right heads for my weak 383(help)
Concentrate on the head/cam/intake combo...wouldn't worry too much about the header debate, yet...never heard of the intake that Brandon talked about above, but sounds like its worth looking into...And yes, I've got a pretty sweet set up...been saving my $$ to send car back this winter for a freshening and a little more cam 219/219 .560" /.560" and a super ram intake...40 more lb/ft and more HP from 4500rpm and up...I guess after 10 years its time...
--Alan
--Alan
#26
Re: need help on selecting the right heads for my weak 383(help)
Originally Posted by SS MPSTR
I see the header debate rage on, but I really don't think the SLP's are hurting him that bad. Hell, George Baxter's car ran near 800 hp with shorties, and found very little gain going to long tubes. There's more to this guys issue than simply swapping or throwing parts at the car. I believe that it's tuning, but I'm not an expert on this issue.
Aaron
#27
Re: need help on selecting the right heads for my weak 383(help)
Heres what I was refering to regarding the intake: http://web.camaross.com/forums/showt...ht=bret+proram
bret or aka (what does aka mean anyways? ; man I'm tired..) sstrokerace
And about the whole exhaust thing your headers, I wouldn't be to conserned about. I would focus your attention to your y-pipe (x would be more benifical) and your pipe size (example 2.5in. pipe flows 560cfms) and your mufflers which will be the corks in your system assuming you don't have cats.
-b
bret or aka (what does aka mean anyways? ; man I'm tired..) sstrokerace
And about the whole exhaust thing your headers, I wouldn't be to conserned about. I would focus your attention to your y-pipe (x would be more benifical) and your pipe size (example 2.5in. pipe flows 560cfms) and your mufflers which will be the corks in your system assuming you don't have cats.
-b
#29
Re: need help on selecting the right heads for my weak 383(help)
so what all of you are telling me is, if i put some long tube 1 3/4 pace setter headers and a 3in y-pipe i wont realy pick up much power?????????????????
#30
Re: need help on selecting the right heads for my weak 383(help)
hey i have a question---->when i ordered my cam for FMS they toll me were i wanted to make peak horse power, so i said 6500rpm, but when i dynoed the car it only made peak power at 6000rpm, so my question is, would this be related to my heads? When i get better heads would my power band move up??? Is it possible that my heads brought the motors power band down???
Last edited by regorih inHous.; 10-08-2004 at 10:59 PM. Reason: wrong