Thinking about intake choices for a mild 383. Cast crank, stock 400 rods, TRW forged flattops, compression around 10:1. Have a set of World S/R heads (1.94/1.50 valves, just a stock style head). Will do a mild home port job before installation, but probably will stick with the 1.94/1.50 valves. Will use headers, and a mild cam (no more than 215-220ish duration)

In light of stockish heads and RPM no higher than 6000 so as not to lunch a rod, would a miniram be too much here?

I think I'd be plenty happy with a superram and if the general consensus is to go with it then so be it, but it looks like a nightmare to install/work on.

Or, would in light of the parts I already have, would I be best suited to an enlarged LTR setup?

Basically, max. area under the curve from idle-6000 RPM for street duty--opinions please.

Thanks in advance.

 

used a HSR on mine. here's the results:

 

Figured it was capable of good HP, but look at that torque!!! Wow, 410 lb-ft.

May I ask which dart heads were used, comp ratio and cam?

 

these which are for sale by the way. http://www.fl-thirdgen.org/mrr23/mrr23-19.html

383 built with these parts: http://www.fl-thirdgen.org/mrr23/mrr23-18.html

 

Superram all the way. It has been proven time and time again and sits in the engine bay of alot of 11sec and 12sec cars.

In all honesty I havent been impressed a whole heck of alot yet with what people on this board are accomplishing with the HSR.

To date though however I am damn impressed with what Mike Davis is doing, 85MIKETPI.

IMO opinion though the HSR is suited more for a bigger bumpstick and a large port head, not a good match for what you are planning to put together.

For me:
385, CC 224/230 .535/.544, E-Tec 170, SDPC base, Superram upper, etc...

Dyno results below.
Track results in the link.

Track results...............

 

OMINOUS_87--thats pretty darn impressive. I've been leaning towards the Superram or LTR. They key for me here is to commit to a direction: either going with LTR/Superram or HSR/Miniram. I'll be doing some searching on 85MIKETPI & check it out, I'm guessing he's using an HSR.

I don't know what to make of the HSR; mrr23 was the car tuned for that dyno run? You have some pretty honkin' heads there & the numbers look lower than I'd expect from such a combo (please do not take offense--none intended--I'm faaar from an expert, just looking to understand the characteristics of this intake). I also woudn't expect power to nose over right after 5000 RPM with the parts you have on that motor. How come you're selling the heads?

Thanks for the replys guys.

 

With that cam the SR.

/N.

 

the dyno 25, red and pink lines, was the best run with tuning. i could've went with a bigger cam. but the overall compression was right at 9.5. was going to be hitting it with about 200hp of the soda pop.

yes mike is using a HSR. www.stealthram.com

i've sold the car and everything. right after we got done dynotuning, we unstrapped the car and i went to start it. made lots of knocking noises. so shut it down. though i spun a rod after 300 miles of running it. being so disgusted with the whole ordeal i just got out of it. sold the car and all. well got someone to buy the shortblock. so i went to take the heads off and wouldn't you know it, there was a screw in #4 cylinder. came off the right TB blade. so needless to say i gave up over a .10 screw. i still have the heads up for sale.

i'm selling my dart pro 1 200cc aluminum heads. have manley budget replacement 2.055/1.60 valves with crane 10308-1 dual spring kit. cut .035" to achieve 60cc chambers. http://www.fl-thirdgen.org/mrr23/mrr23-19.html

i'm selling then with proform black aluminum centerbolt valve covers and arp134-3601 head bolt kit for $1000.

 

I need to get out the Lock-Tite and be proactive about those little screws!!!!!!!!

 

377, I agree about the Superram. It's the perfect intake if you want to take it easy on your bottom end. That cam you described also sounds right for those heads.

 

Wow, that hurts; sorry to hear that, I’m in this motor after only 500 miles so I know the pain.

From what I’ve been reading I am absolutely convinced that for my combo the best intake is the Superram. But, I think I’ve actually made up my mind to go with a converted LT1 intake. I’m sure I will have less area under an idle-6000 RPM curve with the other parts I will be using, but here are my reasons: First, after dealing with LTR for a while I decided that I really don’t want to go to a system that’s even harder to service (this will be a mild streetcar and my laziness here is stronger than my thirst for every last available ounce of torque). Second, I want to run a strut tower brace, so the LT1 intake (or a $$$miniram$$$) is the only choice left. I am trying to stick to somewhat of a budget and after re-evaluating the situation I think the ~$500 or so difference (between a Superram and an LT1 intake) would be better spent elsewhere and I am willing to accept the performance compromises.

Guys thanks again for your inputs.

 

UH OH!!!!!!!!!!!!!!

 

Its not over yet.

In another thread, it was established that with a stock crank I can't go beyond 5000 RPM with any reasonable chance of durability.

Heres the thread for reference:

https://www.thirdgen.org/techbb2/sho...9&goto=newpost

Sooo, I think that going with the LT1 intake will slow me down, especially since I'd be choosing a cam with the intent of building power from idle-5000RPM. Which brings me to the next question--what do you guys recommend? I'll be going with a hydraulic roller.

What will probably happen with the intake is I will get an aftermarket base before the engine is installed, I can figure out runners/plenum configuration (Superram or LTR) later. Now I'm almost leaning in the exact opposite direction, arrgh. But better to find the RPM limit out before it flys apart.

Thanks again!

 

Picking engine parts that go together is a must for best performance but I had to reply when you said you wanted a cam from idle-5000rpm. That's a stock cam and it will slow you down. You might as well run a TPI intake on it. A cam with that range will have little duration and lift.

 

Matching parts is definitely is a must. I have decided to use the bottom end parts I already have, and have found out that it would be a bad idea to spin them faster than 5000 RPM. Thus, I want the engine to produce the biggest average power in this range. I also found out that the heads I will be using will also be best suited to operation up to 5000-5500 RPM on this particular engine (probably closer to 5000 as this depends partially on some basic porting I will be doing myself, and I will be conservative as this is my first attempt).

Thus, I am not sure if an LT1 intake is the best option for this engine as I think the engine I will assemble may be too mild to take full advantage of it. But is it? Looking at the ratings for stock LT1's, the horsepower peaks are typically 5000-5200. I understand that LTR's are typically done by this RPM, whereas the LT1 manifold has more potential and is not the bottleneck on the system. The question is:

Which intake do you guys think will get me the greatest average power/torque in this range?

It has been pointed out that when the LT1 came out it was basically identical to the L98--nearly the same cam specs, early '93 heads were mediocre, similar compression, cars were heavier, but they were faster than the L98 cars.

 

I managed to FUBAR the set of heads I was porting for this, so I decided to good set once and for all so I bought a used set of AFR 190's that will go on this motor. Still the same shortblock (& hence the same 5000 RPM limit). Exhaust will be Hooker 2460's, custom Y (that I alreay have) & 3" cat, 3" Hooker catback. Compression will be about 10:1.

Just to recap--I want the most average power out of this 383 from idle-5000RPM. Heads are no longer a bottleneck, I *think* the exhaust shouldn't be too big of a bottleneck either in this range (If I'm wrong, don't hesitate to tell me). This leaves intake and cam.

Strictly between the LT1 and L99 intakes--Which do you think could net me the most average power in my desired range? John, from your site the L99 port looks only ~0.031 shorter vertically (~2.031vs.~2.062), and somewhat narrower at the top. I can't see whether or not vertical location differs. Looks like the L99 has same runner length, just a smaller runner volume. I'm trying to figure out how this will affect the power curve--would it just shift the entire power curve down (vs. an LT1 intake on same motor) while maintaining the same shape & peak locations (& just resulting in less avge power), or would it just tend to cause peaks to get smaller AND move down in the RPM range (possibly resulting in MORE average power from idle-5000RPM)? I understand I may need to be the guinea pig, but some opinions/speculation would greatly be appreciated.

One more thing--John: If I decided to try an L99 intake, do you know if there is enough 'meat' on it to port to LT1 dimensions if I decide I'd like to go there?

 

How much for the heads?

-- Joe

 

The superram and/or ported ltr set-up will get you the most avg hp and tq. The superram will make more between 3500-5000 than the ltr will. It's the cost of both that is the factor. I would at least get the base for either fully ported or extrude honed in either case.

 

I've got about $200.00 into my single plane EFI setup. (including rails, tb, and so on).

http://members.cisdi.com/~anesthes/p.../test-fit3.jpg


-- Joe

 

Yes, the L99 casting has enough material to port it out to LT1 size ports. The external intake casting is the same, only smaller ports.

 

anesthes: I paid $1K complete w/comp 986's. I figure I'll check over everything & get the valvejob touched up prior to bolt on--any cost savings over the price of a new set is offset by the hassle, but I guess I don't have to wait in line for a new set which is nice.

Single plane conversion is definitely attractive; if I did that I'd make a bolt on plenum & use a TPI TB. Now with the Victor EFI all the hard stuff is done for you, though DIY would be more economical as you can attest.

Superram is definitely the best choice 'on paper'--this engine has enough size or RPM capability in order to consider the SR a bottleneck. Its just that the 1-pc intakes (I'm including the HSR in this though the plenum is seperate) are so simple it hurts. If the MR or HSR had EGR I wouldn't even consider the SR despite the fact that in light of this motor's limitations I'd probably go slower.

Why am I considering the LT1 if I'm worried about EGR? Well, I figured I could keep it by either using the MSD wet sump oil plug or making my own out of an old distributor, adding a cam position sensor (probably to timing cover), crank position sensor, and using the FAST edist with LS1 coils. This way, I'd have a great intake AND CNP ignition, for less than a MR. But, this is still would have enough of a cobbled-together look that an emissions ref may not like (no visual in IL yet, but I have a feeling emissions regs are only going to get stricter). Of couse, I'd probably have a better chance with a MR or HSR with a custom "divorced" EGR.

Heck, maybe I should just leave emissions legality out of the equation and swap manifolds come emissions time.

Considering the headache I get whenever I try to decide on an intake, I should probably just pick one & shut the F up about it. For what the MR costs though, the damn thing should at least be emissions legal.

 

heres a good deal on a miniram..

https://www.thirdgen.org/classifieds...tgo?adid=48635