What kind of rear wheel are we seeing in 383's?
 

Matt 96z and I were talking about his 383 buildup today.

I was wondering what kind of rear wheel hp numbers guys are seeing with a built 383?

My guess is that his 6 speed car will get 430-450rwhp on a budget, but I'm wondering what people have already picked up.

The 383 is a Scat bottom end, LT4 heads ported for about 290+cfm, LT4 intake and a Hyd Roller cam. Those are the basics. So 430-450 seems reasonable.

Thanks,

Bret
Bauer Racing Engines

Too many variables to determine rwhp. But I'm sure you knew that since you build race engines (Bauer Racing Engines ).

I already guessed 430-450.

I was asking what other people have done

Anyways, nice ET but I gotta love my LS1, runs the same MPH with a lid, ported MAF and a ported TB on a LS1 intake.

Why can't you ask a question over here and not get some jerk comment? God I asked about a 110LSA and some guy thought I was the dumbest guy alive! I know what it all does and why a 110lsa can and can't work or how to figure rwhp I want to know how other 383's with heads stack up?

Seems like a legit question to me

Bret

I have 1 customer that "claimed" 450 RWHP with a 6 speed 383 but he never showed me a dyno graph and he claimed 450. Not 452, 456, 447, 441, etc, etc, but 450......HHHMMMMMM. Kinda make me wonder if that was his "estimate" instead of actual dyno #'s.

As far as actual dyno #'s I have seen 390 or so with a Hot Cam, 6 speed and stock rearend, LT's, no cats, etc.

I have also seen 410 from an A4, 12 bolt, cc306, LT's , etc.

I have also seen 390 from a TH 400, 3500 stall, 12 bolt, cc306, LT's and a stock tune (ran out of $).

Cody (Red97SS) has a 383 but I do not know if he has ever got it tuned or dynoed. He has a 12 bolt I believe and a 6 speed.

None of these cars had a cut out, electric water pump or a dyno-tune, these were all mail order tunes setup for other combination.
I am not sure about Cody's, he might have an electric WP but I am not sure.

I have seen 390-420 RWHP on STOCK BOTTOM ENDS with a cut out, elec. WP, etc but for what ever reason I do not have much better peak #'s from the 383's....???????????? More torque but not much more HP.

NightTrain66

I don't have any numbers yet but I will this spring. To date I have run a best of 121 MPH through a Borla with no plate, Hooker LT's, and no cats. That was with a Hypertech PP+ program with adjusted cylinder volume and injetor size (Done with LT1 edit).

No other program changes have been made since I spent most of last summer chasing down a LT1 edit logging problem. It ended up being a loose connection at the PCM.

BTW - Where are you located Bret? I know you are upstate but just wondering which town.

If the 383 was built right you should see at least 450hp at the crank from a moderate size cam.

Thanks guys so far.

Red,

I am in Elmira, our goal for the engine is about 121+ so sounds good.

NightTrain,

Yeah that 450 seems iffy to me too, I'm guessing 430 tuned or so.

Seems to me that all displacements are going to be HP limited by these intakes, but cubes never really ad any peak power most of the time, it takes alot of work to get the same HP per cube on engines, just upping the sizes of things doesn't always work.

Bret

Probably b/c alot of the "internet expert" types mistake hearsay and 4th, 5th, and 6th hand information for fact:) No real world experience required.

Just hop on your favorite UBB, simply repeat what the majority of the members chant, and suddenly you become a bona-fide guru. As you can see, perpetuating "myths and misconceptions" is inevitable under these circumstances.

Guys that have never run headers know what headers churn out the most power, guys that have never run a cam bigger that stock know exactly how much duration you can get away with before drivabilty becomes unbearable, and everything inbetween.

God bless the internet:D

When some of these folks have the audacity to go head to head with the occasional engine builder/professional that we're blessed to have on here, equipped with "internet myths" instead of mechanical engineering degrees and years and years experience, I can't decide whether to shake my head or laugh hysterically:confused:

To answer your question, my old motor put down 436 RWHP through shorties and a 3". With a good exhaust, 450 shouldn't be a problem.

Cool. Maybe I will see you at NYI if Rich gets a T&T day set up.

Jim S. '95 Z28, I can't agree more.

450 might be doable, considering the budget if we do that, I'll be a happy camper

Red, I'm in on the NYI day, gonna work on getting so launch stuff and a new set of DR's to work. I'm a autocrosser, so am looking to play with the SS at the strip, it's a much better car for that.


Thanks,

Bret

I've seen a number of 383/396 dynoes (including my own) and I'm not afraid to say making 450rwhp is not that easy. I've seen a well put together 383 with the CC306 make 420rwhp. I've seen a 396 with ported Lt4 heads with a 234/242 112 Crane cam put down 432rwhp (with 14+:1 AFR, so there was more in it). 450rwhp would probably require large port heads, full on exhaust, and a pretty big hydraulic or medium sized solid roller cam. All the numbers I mentioned are SAE - I don't look at actual.

I guess it depends on your goals, how much money you have, and what you call "streetable".

Oh, and I personally don't think 420+rwhp can be done with the HOT cam.

-Alex

Good for you! I've seen several Completely STOCK LS1's at Gateway run my same mph, yet they are in the 13's...... MPH doesn't win the drag race... :)

If you knew the answer to your own question then why ask it? :) If you build race engines, then you know that there is too many variables to determine rwhp. :cool: I wasn't being a jerk, just trying to be informative. My guess is that a 383 will make between 390rwhp and 475rwhp, depending on CAM, Heads, headers, and CR.

Alex,
Who made 420 with a Hot Cam?



Stroker,
All of the #'s I mentioned were on LT1 castings and larger valves. At that cubic inch and target HP level the LT4's (or AFR's) extra runner volume could be the X-factor. I guess it is possible with LT1 castings to make the 430-450 but if you ever reach it with LT1 heads you should see a pretty good increase with LT4's or AFR's. These heads are all 180-185 cc, this small runner might be the reason for these HP #'s that I mentioned.

??????????????????

NightTrain66

My very mild 381 made 425rwhp with the M6 (12.8% loss). After the TH400 conversion, the rwhp dropped to 390 (19.8% loss). And that's an engine configuration that was selected with the goals of excellent street manners, the ability to pass rolling emissions, and the ability to handle a 300-shot of juice. The juice seems to involve a number of compromises that affect N/A HP, like the heavier pistons, 5.85" rods, wobbly pistons from dropping the ring pack, wider LSA, etc. I don't think it would be hard to make a big improvement in my results if streetability, emissions and the nitrous was not a factor.

Fred: Weren't/aren't you running a solid roller? If you were running a hyd roller, how much difference do you think you'd see (assuming the the hyd was somewhat similar: pass emmissions, good driveability, etc)?


Ryan