I'm getting ready to redo my 383 and need some help picking out the parts. The current setup is in an 89 camaro, weighs 3850 with me in it. Engine is a 383, motown 220 cast iron heads ported, lunati solid roller #50169, 281/285 adv. duration, 248/252 @.050. .606/.585 lift. 10:1 compression, victor jr and a holley 4150hp 750. Trans is a level 4 raptor from PACT, 700r4 with a TCI street fighter converter..i think around 3200 stall. The car runs 12.5 1/4 mile at 110. I also want to keep it on pump gas. Don't really want to run nitrous.

I want to be in the low 11's or break into the 10's. I drive the car maybe 5 times a month on the street, occationally bring it to the strip.

Now heres where I need some help. What heads and cam should I step up to? I think im going to stay with the 383. I've been considering the new eliminator AFR 210's with the competition porting, and 65cc chambers. That would give me about 11:1 compression, maybe a hair less. The cam I have my eye on is a Lunati solid roller, part #60134, 285/293 adv. 255/263 @.050, .600 lift. Would that combo get me where I want to be? Im also thinking about upgrading the torque converter to a 9.5'' 4000 stall. The cam is really what I need help with i guess. What about the AFR 195's?

I think my intake is still ok but not sure about the 750.

At 3850lbs, my car is heavy...i think GM accidentally made my floorboards with lead!

Thanks for any help, I've been doing a lot of research on this forum and know you guys give good advice!!

 

For the street, I would go no higher then a 200cc head. 11 to 1 pistons with 65cc aluminum heads will give you about 10.5 to 1 or 10.75 to 1 compression which is still able to run on pump gas (maybe alittle octane boost wouldn't hurt either). With that Lunati cam and that much stall converter, don't expect that to be comfortable on the street.

But anyway, start by reducing weight, then work on planting the rear tires to the pavement as much as possible. No matter what power the engine makes, it needs to be able to keep it on the track and not sideways or breaking the tires loose. This will involve alittle chasis tuning. What rear-end and gears you using?

 

Thanks for the input. Rear is a Moser 12 bolt with 4.10 gears. Im not too concerned with bad street manners. Man I don't even know where to start as far as shaving pounds! A/C is gone, front sway bar is gone, thats about it so far. Only about 500lbs. to go...

Pistons are flat top with 5cc valve releifs, .005'' deck hieght, .039'' head gasket.

Pretty sure im going with new AFR's. 195's or 210's...not sure

 

Is 575 horsepower an unrealistic goal for a semi street pump gas 383?

 

A little too much for the street, but can be done at a price.

 

575 is pretty high up there for a 383. 550 is abit more realistic.

For some reason i think your car should have gone alot faster than it has even at that weight.

I'd go with those AFR 210's. That lunati cam looks pretty good. Run a bit bigger carb too.

4000-4200 stall will work ok. That should get that car moving into the mid low 11's. I dont see why it shouldnt. My car was lighter at 3450 lbs but could go 11.4's without problem with AFR 195's and a smaller 230/245 hydr. roller cam. 400 more lbs would push me closer to 11.90's i'd say. More head more stall and more cam should definately go mid 11's

 

Thanks for the replies. When I built my current engine, I was really expecting high 11's. I'm not sure why it's only at 12.5 and 110 mph. Im thinking my the runners on the motown 220's are too big and not flowing a lot of cfm...low velocity air?

 

they are abit big and probly dont have the air flow like some of the other aluminum high end heads out there. Probly some power to gain with a good seat of heads

 

The exhaust system I have might be killing my power...I've got 1 3/4'' hooker super comp header and a single 4'' muflex system with a single 4'' flowmaster in the rear. Do you think the 4'' is choking the engine?

 

4" is more than enough for that motor. It wont choke until over 650hp

 

thanks for the advice. I think im going with the afr 210's. with my pistons i believe im going to end up with 10.8:1 compression. would you guys recomend any other cams other than the lunati #60134? I can deal with low vacuum and not so good street manners, im just wondering if I should turn over 7000 rpm with a 383. My rotating assembly is going to be all forged.

 

Well you dont have to turn over 7K rpm to make power with AFR 210s. If anything i'd shift by 7K and have the cam peak at 6600-6800. That will be a better grind for streetability.

That cam you have selected should more than likely do just that, peak by 6600-6800 and give you a 7K shift point. Should be close to 550 hp on motor, maybe abit more. I simulated it on a rough simulator and got near 550 on motor.

Also if you could, you could try abit more rocker arm to get more lift on that cam. 210s like .650 lift or closer to it.

 

agreed with all above.., expect the don't go bigger than 200cc... while it is good to keep velocity... you have the cam to make the bigger heads work.. the 210's would be sick.. bet you pick up 3/4 sec. with those alone...

why don't you just try a head swap with current cam, bigger stall.. 4000 or so
and bigger rocker, 1.6's...

bet you would be deep in 11's... your 750 should be ok, but try a friends 850, see if you pick up any top end (if it is any better you should notice on your mph)

 

and im sure your motor would love a little 150 shot...for sure lol....

 

Thanks for the help guys. With the 60134 lunati cam and 93 octane fuel, could I bump the compression up a little? 11 or 11.2:1 I'm still not sure if thats the cam I'll go with. I NEED at least 550hp!

 

give it 11-11.2 to 1, with a dead on tune and AFR 210's. That 383 will fly

 

When getting up into the low 11's with your compression make sure your quench distance is good. With that big of a camshaft you will bleed off some compression so I would imagine there will be no problem with your dynamic compression.

 

I agreed with that compression ratio and the heads 210 afr will be perfect and i think you have to watch closely you carb. Probably it going to be small for low 11s or high 10s on a heavy car.
And get out of the hole @4k with a 700r4 i think it not going to last longer !

 

Are you running a cat and also is it 4" from the headers back? it sounds like u have next to no back pressure. my buddy had a 355 stroker in his S10 and needed 2 cats (1 for each side) to get the backpressure up, he picked up about 1/2 sec with a little bit of back pressure. Every engine needs a little in order for the scavenging effect to happen in the cylinder. The low pressure vacum that back pressure gives allows the engine to expell the exhaust gases better.

 

My long tube headers have 3'' collectors, I have a Y pipe off them that turns into a single 4". No cat, that exhaust runs to the back of the car same as the stock exhaust did. 4" flowmaster muffler behind the rear axle.
Thanks for the input!

 

Exhaust should be fine, you actually dont really want any backpressure. Free flow is good but its the tuned length that really makes power. Most long tubes have varying length of pipe and are not equal length, so each cylinder is tuned over a broad rpm range. That can be good for a street /strip type car that may see a broad rpm range. More drag oriented setups want more equal length since they use shorter rpm band.

The tuned length can be calculated and depends on cam timing events and motor peak rpm. Most motors over 6000 rpm peak power like total collector length of 18" or so. thats why high reving race cars run short collector open headers and SHOULD run faster with open headers than full exhaust, not because of greater flow but because its tuned length makes more power by being able to scavenge exhaust gas out of the motor more efficiently AT that specified RPM range of 6000 rpm.