Any comment on best combo for a 383

 

A HSR ;
similar cost and more potential than LTR on a big cube engine

https://www.thirdgen.org/forums/alte...gal-whats.html

Read

http://xtremecarzone.com.au/index.php?showtopic=386

 

Understood,but not willing to lose any low end power or hacking on my GTA hood.

 

Since the hsr is out my vote is for the street runners if you can find a set.

 

Exactly what are street runners? Never heard that term used before

 

youre not going to lose any torque
Just an opinion but the airspeed is so high with the LTR it gives great throttle response mimicing something that really has more torque. Doubt theres a real life difference at all;in fact bet with the stroker you may LOSE torque with the TPI as the runners are too small and long period even with porting. Opinions may vary
Go for the HSR


Ex;did an aggressive port job on a couple Superrams last yr. Few commented how the car would lose tq blah blah guess what it picked up everywhere. Car picked up +3 tenths and 3mph in the 1/8 alone without a retune. Did dyno it cant recall the #s but they picked up.
One Im doing now (for a 383 also) which is WAY more aggressive (runners are 2x2 in) will gain even more. That to me says the LTR period even the SR is still restrictive.

 

Accel made a street ram, these runners were used on it and sold seperatly.
The only accel LTR I know of.

Ill sell you a sr

 

Missed the HSR being out

 

Not a problem with a 383 ; in actual fact a benefit if you want to launch hard consistently
The improved 60ft time in the link below shows no lack of bottom end

"it appears the stock StealthRam improved elapsed times approximately .3 second and added close to 3 mph over the modified TPI/SLP intake system's best run.
The StealthRam also improved 60-foot and eighth-mile times and speeds.

The StealthRam achieved and surpassed the desired results. It was amazing how it rolled off just enough torque around the stall speed
to allow the car to be launched at about 95 percent of its capability".

http://www.gmhightechperformance.com...hird_gen_iroc/

 

There are mathematical equations based in physics that will confirm longer runners make more torque than shorter runners – as long as they’re not severely under or oversized. The Ten Times the Torque sticky shows actual dyno results of different intakes on a relatively health “500HP 383”. The greatly undersized stock TPI made no less than 29lb/ft and as much as 53lb/ft more torque than the HSR between 2800 and 4000 rpm. The still undersized aftermarket TPiS long runner system made no less than 51lb/ft and as much as 62lb/ft more torque from 2800 to 4000 rpm - that’s a SERIOUS difference you can most definitely feel in throttle response within that range.

That said, not knowing what cam, exhaust, heads, transmission and gears the OP has,, and whether or not he’s thinking about changing any of that,, specifically gears and stall speed,, it’s hard to say what would work best for him. It just might be a HSR,, but not everyone’s main concern is quarter-mile ETs.

OP, what’s the combination now, what do you not like about it,, or what more are you looking to get out of it?


Yep,, I was feathering the throttle on the TPI/SLP combo past the 60ft mark - it would not hook for squat,, and with the HSR and a good burn out, it would take full throttle out of the hole. However,,, after the buzz wore off,, I started really missing the TPI's throttle response. I switch to a FIRST and it moved the torque band up just high enough to let me run better 60ft times than the HSR (still feathering the throttle a little), have almost as much throttle response as the TPI/SLP combo,, all while running near identical (slight quicker) quarter mile times.

 

The HSR is out, don"t want to hack on the hood. My question was between the ported accel slp setup and the FFI. This is what I have and not looking to change anything except maybe the cam. Got a ported stock intake with slp's now. Looking for more power everywhere. Don't want to lose any low end grunt.

This is a stoplight to stoplight car, not a dd,no track, with some long distance highway use.

10.2 cr
comp 502 cam
dart shp heads
hooker 2055's to 3" freeflowing exhaust
built 700r4
slightly higher converter
3.23 gear

 

The intake comparison I linked above show the merits of each
Pick your poison
( compare the graphs , not the numbers )

 

The internet really ruins the reputation of intakes like miniram and hsr with this low end torque stuff. Everyone says go lsx yet those motors make same type powerband as a hsr swapped car

383 makes torque there is no losing low end. Short runner intake just gives you a flatter broader curve instead of a sharp peaky one like tpi

But if you want tpi i would throw on the biggest base you can and largest runners depending on heads and cam. Cam will need to be shorter duration to keep power in tpi's power band although you can cam it up and just turn high rpm with a dead flat hp curve. Thats not a bad plan... However that setup would make 30-50 hp more up top with short runners tuned for that rpm. So its a big deal.

If the cam and heads are smaller then tpi isnt a bad deal. You wanna make big power have to turn rpm and add cam.

If the slp type runners are siamesed alot and base really ported well with injectors moved up for 1205+ gasket size port, you can get best of both worlds. Tpi torque to some degree and hsr top end to some degree. An inbetween like a modded superram

Either first or slp siamesed, i would sell cam for the 503 in a 383. Maybe even the 276 version on a 110 lsa

 

Thank you

I understand the OP's choices but hate to see a decision made on bad assumptions or hearsay

 

I agree.

scoflaw, I was doing a search to see if I could find more information on your combination. Did you locate the source of your oil consumption? If not, you really need to check cranking compression and do a leak down test to make sure there's nothing major wrong. I can't help but believe based on the lower than expected output you're at the very least sucking in oil from the lifter valley/intake. I say that because assuming the 180 SHPs flow as advertised, theoretically,, the rest of your combination and what I was running on my old 355 IROC is very similar. Not sure about yours,, but I put a lot of work in the stock base (ported the entire length of the tract) and SLP runners (fully ported with the dividers removed to about the halfway point). I was also running one of the highest flowing single inlet dual outlet mufflers (hopefully you’re not running an 80 series Flowmaster). Anyway,,, I could spin relatively sticky 245/45/17 street tires from a roll anywhere in 1st gear. With 30 more cubes,,, you should have even more traction problems.

Anyway,,, if I were you I wouldn't change anything until I was sure everything you have now is working properly. If something is wrong,, once fixed,, you might find what you have is more than adequate for a stop-light to stop-light car that you don't plan on racing.

 

Thanks for asking about the oil issue, yes indeed the quart every 200 mi. was coming from the intake rocker studs, hard to believe but true.

I'm not saying this car is a complete slug, but slower than other cars I own, which have over 400 rwp. Just looking for more, it's going to be a long winter, and I want to make some improvement on it. You make a good point about what the cranking compression is, and I will be checking that as well. I have my doubts about the 502 cam I have.

How do you fully port a slp runner? Like the middle of it?

 

HSR would be my first choice, but since thats out Mini Ram.

LTR is just a waste on a 383 unless its going in a truck.

 

Cut the cover off the slp, port middle and then weld cover back on. Search dyno don's posts for pics

 

https://www.thirdgen.org/forums/post...714-post9.html




https://www.thirdgen.org/forums/tpi/...owing-tpi.html

 

Hate you had an issue,, but I'm glad it was something as minor as that. As others have said to fully port an SLP runner in the middle, you have to cut it open, grind on it and weld it back up. I did say I had fully ported mine,, but I ported as much as you can without cutting and welding. When you fully Siamese the top half, removing the divider from the top of the runner to the floor, you can cut away to almost the halfway pont of the top of the divider with a 6' long burr. You can’t get to the halfway point of the bottom half of the divider, but fairly close. It is a major pain though. I wish I had pictures of my old SLPs,, I did a search to find a comparable picture and couldn’t,, probably because it is such a pain to do.

I did find the video below that shows the tools and how far you can get the 6” burr to go down into the runners without cutting and welding - this is not an endorsement,, I’ve never dealt with him,, but it’s a pretty good video. At least you’ll get an idea of what you could do to what you have now. I would not spend any more money on it – if you would have to pay someone to do it,, sell what you have and get another intake.

I’m probably one of very few people that has run a fully ported (not cut and welded) TPI/SLP combo, a FIRST, and a StealthRam on the same engine/car (no other changes). Each one had different minimal cross-sectional areas and length – because of that they had different power bands and varying peak HP and TQ RPM (you can see this in the Ten Times the Torque article posted earlier) . The StealthRam performs about like a carbed dual plane down low and makes within a few HP and RPM of a single plane up top – it’s a nice intake,, no slouch like I said and makes decent midrange power and has good throttle response,, but nothing like the FIRST.

The FIRST on the 355, while only running mid-12s (shifting at 5800/5600 rpm),, with a small hydraulic idling around 750rpm felt every bit as strong under partial throttle and playing around as my other car with a roller cammed 406 idling at 1300rpm that was running 11-teens. While the StealthRam also ran mid-12s on the 355 (shifting at 6400/6200),,, it felt like a mid-12 second 355 with a dual plane that could pull well to 6400rpm – again,, no slouch,, but the FIRST was a lot more fun to drive on my combo. If I was running a 5 or 6-speed with 3.73 gears,, I know I would have preferred the StealthRam - the shift recovery is high enough on those to keep it in the intake's power band and there is the option to select 2 or three more gears.

I’m giving the above reference not to get into some kind of a pissing contest,, but if you’re used to driving fairly quick big blocks and only going to be running the car from traffic light to traffic light,, it sounds like if what you have now with some extra self porting won't cut it,,, the FIRST might be a good fit for you. Assuming traction it’ll probably run every bit as fast or faster than a StealthRam (for sure a MiniRam) on your combination - small heads,, small cam, small exhaust, automatic with a low shift recovery RPM, 3.23 gears,, 2000-ish stall and would make your 383 feel about like you were driving a much quicker 427 big-block.

Now,, there’s no question if you cam, gear, and stall appropriately for a short runner intake,, the car will ET faster,, but it doesn’t sound like you’re looking to do all that.

 

Seeing that I have an accel manifold and the slp's and it's going to cost me $300 to have the accel ported to 320 cfm. Is that a better choice than a FFI out of the box? I like the linkage setup better on my 58 Holly TB as well.

Also wondering if a 503 cam is worth the effort of switching it out for my 502.

 

320cfm TPI base for $300?

I dunno about that ....

 

the 320 or the 300?

 

$300 seems cheap for 320cfm out of an aftermarket TPI base - I thought they were costing around $150 to weld and $350 to port.

That aside,,, you have to treat the long runner intakes as a complete system, so to get the runners up to part,, you need to have the SLPs cut open,, all the little indentions welded, and the internal diameter opened up enough to keep up with the base, on paper it looks like it could keep up with or best an out of the box FIRST. However, I have no idea what someone would charge to do the runners. I'd hope they would have a programmable mill to cut out the majority of the meat in the SLPs,, it take a lot of time to do by hand (even taking out what you can with a cutting wheel) Unless it is someone I know locally,,, and have nothing else to do,,, I won't port any of the GM TPI stuff anymore. I just don’t feel comfortable charging 1/2 the time it takes me by hand. I’m sure if I did something like this full time,, I'd be faster,, not sure about twice as fast though - lol.

I know the welding and porting they do on the GM-TPI base is to help with the inherently bad head transition and you can shape and “off-set port” (to a degree) the entry of the base and the exit of the cast runners to help with the bad runner to base transition, but I’m not really sure how much that helps. The FIRST’s runner to base and base to head transitions are excellent – all you really have to do is a little gasket matching and very minor “clean-up”. That said, I’m sure the ported GM-TPI system would be more than fine, if not overkill for your head flow – with your head flow anything in the range of 275cfm would “work” - which is about what a well ported (not welded) aftermarket base would flow.

I’d add up the cost to port everything to at least the 275cfm mark, then what I could get by selling everything as it is now,, and compare that to the FIRST (add in a regulator and about $100 worth of line and fittings). Whichever was the most economical, I’d go that route,, which I’d guess what you have now since you already have all aftermarket GM-TPI stuff. That is unless you luck up and find a used FIRST - it took looking every night for months each time,, but I picked up the two I bought on e-Bay for $500 each.

Cam,, it’s definitely small for 383 even with a relatively stock TPI, but you have your 2000-ish stall speed to consider. If you don't want to change stall speed,,, and were to go the economical route by just hand port and siamese as much as you could on the SLPs,, I’d say it wouldn’t be worth the swap. If you change to either a welded and well ported GM based TPI or the FIRST, I’d determine the highest stall speed I’d consider running and cam accordingly.

It’s a bit of a slippery slope once you start changing up parts - honestly,, about the only thing you could change and not really need to change something else is port the SLP runners and upgrade the exhaust system with a set of long tube headers and 3.5-4” pipe to a 3.5” to 4” muffler - I would do that whether or not I did anything else.

No disrespect,, but those heads were not the best of choice for a 383,, or even a 350 for that matter. I'm not so sure swapping over to a set of AFR195s and "non-welded" porting to what you,, running the same cam and stall speed wouldn't be faster than spending a lot of money on a FIRST (or porting what you have) and swapping the cam - it might cost less to boot (depending on what you can get for your current heads).

 

Also think the FIRST would be the best solution to a true 300 cfm TPI. Noone that knows what they are doing will do all that to a TPI for a few hundred, most shops wont do them at all its just too much time involved;they are a convoluted piece.
Dont mean to sound opinionated or discouraging just sayin. Remember about 10 yrs ago I asked a local shop how much to do a base. $800 they really didnt want to do it either, noone did. Thats when I bought tools and started ruining parts trying to learn lol

Will have some interesting flow data coming soon on stock/ported TPI pieces not that it hasnt been done before
Hoping for 300 but highly doubt it (accel). Do the best you can with it you got what you got;need more get a shorter runner intake same old thing.

 

If your looking for a first,i got a brand new first with a full port job for sale for 1000.00 minus the throttle body.Flows 308cfm on number 8 port.

 

Few more pics

 

Darin D. from Iowa says he can get the accel base to flow 320cfm with no welding. He did my stock base, looks good,says it flowed 270. Not sure if this guy is blowing smoke or what? I know he beat me on the slp runner port job, did both ends but nothing in the middle. I'm sure flow machines are are just like dynos. It's not like someone is checking these things accuracy with a standard in mind.

So if my heads only flow 250 at .500 am I wasting my time with mani and runners that flow 300?

 

At this time FIRST does not appear to be planning on making any new setups, so unless you can score a used one, it would seem a lot easyier just to go with a stealth ram.

 

Bad information Johnny, just got an email from Ken this morning. They have them.

 

320 is alot thru a non weld port shape. Thats 1205 ported and i think min csa would be around the entry to the head. Seems optimistic but hard to say

And no its not a waste of time necessarily, as the intake may help or hurt the head. You need to test them together to see what happens but most of the time the manifold will bring down a head slightly with no work done to the manifold. If manifold flows substantially more it may help head flow or at very least not drop off any flow in the head.
You just dont want the manifold to feature larger cross sectional areas as it tapers from runner to head inlet side and then bolt to head that tapers again in different dimensions. That change of area can hurt flow. You kinda want the manifold port matched to head and then ported accordingly.

 

If youre not sure and would help make youre mind up send it to me Ill flow it out of my pocket you cover shipping. Made the fixtures.

% of gain is whats most important

 

Interesting. I was going off the thread that's been going for about a year asking when they were going to be avalible again, and the reply kept saying 2 months.

If he has them ready, I bet there will be a lot showing up here again soon.

 

Says he's planning on not running out again. If he floods the market that should bring the used prices down. Huh?

 

I would love to see the results, I'm skeptical of his claims. I wouldn't let him touch a set of heads even if they were free. I saw some of his work on some 113s a while back not impressed how he jacked up the guides.

 

http://www.ebay.com/itm/High-Flow-Tuned-Port-Intake-by-First-Fuel-for-Small-Block-Chevy-/251418719169?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a89b933c1&vxp=mtr

 

Going to make some popcorn. This is going to get dramatic soon LOL.

 

Here joe

 

Looking for a bit more advice. Going to go with a ported welded accel manifold and hog out the SLP's more. I am undecided on which cam to run at this point and was considering a xfi 280. I will be pulling the motor to install a better converter and was going to pull the heads to bump compression a bit more, like 10.5 to 1.

If I'm still not happy with the tpi output I can change that without pulling the motor again. Looking for a cam suggestion with a quality converter that I will be happy with for street use. I do realize my computer will need ebl flash so that won't be an issue.

Is the xfi280 too aggresive for the street?

 

There is a real nice accel on ebay right now. that's a heck of a lot of duration to try to run with tpi.

 

An accel what? I was going to go with a 1.52 rocker. which puts it at 230-236 547-542. Which still might be too much. Maybe xfi 276? If I do decide to dump the tpi I don't want to change the cam again if possible.

 

I guess the accel intake sold, but this was the seller.
http://www.ebay.com/itm/Accel-Lingenfelter-Super-Ram-TPI-intake-Polished-/161192102598?pt=Motors_Car_Truck_Parts_Accessories&hash=item2587cc4ac6

 

the 276 would be a good cam

 

Order something like this then.... Xfi 3015/3036. 274/282 224/230 .573/.568on a 112. Would work in between 268 and 280's, be very mild in a 383 with good heads yet still make steam in a short runner intake

Or throw the milder xe exhaust lobe on 3315 282/230 .544 w 1.6 rocker

Xfi has alot of lobes now. Could do a 276/282 226/230 as well. Tad bigger. Or even a 228/232

Actually with shp's you may want abit more duration split. I like the idea of the 226/232 276/284 cam
But to be honest an xfi280 isnt big for a 383

 

Thank you Justin, not sure I understand the 276/284 part. Is there a decent out of the box converter that might work with that last choice Thanks Mike

 

What are the cam specs for the 280 ?

 

Post 41 but that's with the 1.5 rr obviously more with the 1.6

 

Sorry, not sure what the heck specs I was looking at when I googled it.

 

I would go custom converter. I like higher stall converters. 3600 is awesome in a 383. 4000 for a 355 with the 280 cam. More street drive 3200 in 383 or 355 but just dont expect to 60 ft as well as it could. Actually if you are afraid of converter go 2400-2600. I have tuned a 360" car with the 280 cam on stock converter. Drove great. Tpi siamesed peak torque should approach 3800-4200 rpm. Hsr 4000-4500 with 280 cam. So converter stall should be near that for optimal et

 

I've ported a set of SLP runners before using a ping pong ball as a reference. I was able to get the ball to roll evenly down each runner. With that being said in my honest opinion SLP runners aren't work the money. Out of the box they are literally the same as stock. I know it hasn't truly been brought up but have you thought about going single plane? With a 383s torque it shouldn't matter. As far as Drains work goes I think for tpi bases he does a fabulous job. Ive ported some tpi bases myself and its no small task. But....I'm not to impressed with his head porting. It leaves much to be desired.