Who makes the best long runners and why? (best horsepower and torque)I have heard that the SLP runners didn't live up to the 18HP claim they make. I know you make more power when the plenum and base have been modded but which is best? TIA.

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89 IROC-Z 5.7L
130,000 MILES
2.77 GEARS
K&Ns FILTERS
ALL FREE MODS
FLOWMASTER MUFFLER
PERFORMANCE RESOURCE CHIP
Best 1/4 E.T. 14.37 @ 95 MPH
Best 1/8 E.T. 9.22 @ 76 MPH
Best 60ft. 2.07


[This message has been edited by whiteroc (edited June 11, 2001).]

 

I enjoyed a decent amount of success with my Accel runners. They were put on at the same time the Edelbrock base was so I can't speak of benefits from the runners alone. The Accel pieces are the only ones that are cast aluminum, I believe, and offer a bit more room for porting than the others.
BTW, I don't think there is a manufacture's claim out there anywhere that holds 100% of its weight. That 18 horsepower must have come from an engine that previously had tube socks for runners.
bsa

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"If they do not run, Then they will die." - Stonewall Jackson
#3
'87 IROC, 355 TPI, Converted to SD, 700R4, B&M Megashifter, 3.42, Trick Flow Twisted Wedge Heads, Edelbrock Intake, Accel Runners, Comp Cam, Crane Gold rockers, Lucas 24# injectors, Edelbrock headers, Flowmaster 3'' exhaust, Mallory Ignition, Transgo Performance Shift Kit, Corvette Servo, 2,000 Stall Torque Converter

 

Accel runners, when installed on my basically stock engine made a solid 3/10ths reduction in ET at a 3000' elevation dragstrip.

http://www.geocities.com/MotorCity/G...ft/index2.html

 

AS&M or TPIS, they are both the same, are the best. And they look nice too, get the siamesed ones they'll give you more upper rpm power..

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GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTR, !plenum, 52 TB, MSD 6AL, TPIS level V prom, Superior shift-kit and all the minor mods, a Canfield headed 383 in the works!! ready May 2001...ok..june...
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)

 

The SLP runners are cast also and have a huge amount of material that can be ported. They can be siamesed any length too. If you get them ported or extrude honed they work well. Also since they can be fully siamesed to any length they can be set up for most any RPM range you need. If you just want a set that you can bolt on without porting first I wouldn't get them though.
As cast they have a fairly small port diameter.
You can also port and/or extrude hone the cast Accel units, but siamesing them would require cutting and welding. They work best at low to mid RPM ranges do to their full runner port length.
The AS&M and TPIS units have already been siamesed and will work best at mid to upper mid RPM with a small torque loss at low RPM, and a decent HP improvement at higher RPM. They are welded up from tubing and sheet metal. So there is no room for additional porting, but then they are already pretty good as is for their intended use.
AS&M also have a full length non siamesed version. They are designed for low to mid RPM use.

So as you can see the best choice really depends on your plans and needs.

With an otherwise stock or near stock engine and the 2.77:1 gear ratio, I would go with the long tube non siamesed type to make the most torque and HP at as low an RPM as posible.

•I would choose the AS&M long tubes as a first choice if you don't want to do(or get done) any porting work.
•If you can port or get them ported (extrude honed would be best) then I would go with the cast Accel+extrude honing for max flow.

If you are going to make future mods that will raise the RPM range of the engine and maybe do a gear change too, then I would get siamesed units.
Again, If porting is out of the question I would go with AS&M or the TPIS siamesed.


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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

EFI Performance Club on Yahoo

[This message has been edited by IROCKZ4me (edited June 11, 2001).]

 

Bang for the buck you can't do better than the SLP's unless you are intending on just slapping them on out of the box. You could almost swear SLP knows you sould mod them because they leave nice big hunks of casting flash and a brick wall for the air to divide around. There's so much meat in them you could prolly tune for just about anything (and digging it deep into the manifold can't hurt)

It's the poor mans superam or a sleeper/almost stock look deal.

 

Whoops, forgot the SLP units were cast.
bsa

 

Anymore thoughts or ideas?

 

How about edelbrock runners? I just bought a like-new edelbrock base and runner kit for $325 and my old base and runners but have not installed them yet. Thats what I call bang for the buck!

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1990 Firebird Formula 350 speed density TPI; K&N, air foil, throttlebody coolant bypass, underdrive pullies, MSD 6AL, MSD HEI coil, 8.8mm wires, , Hypertech Stage II chip and AFPR, 160* thermostat, fan switch, B&M stage 2 shift kit, Edelbrock 1&5/8 headers, !Cats, !AIR, Flowmaster 80 series muffler, 3.73 posi rear end

 

Chris Petris, a corvette guru and technician wrote an article on which runners performed the best...Accel came out on top...TPIS and ASM are the same stuff...they didnt perform as advertised..but they said ASM are good quality to install and a better deal over stock.

Some people on the vette forum tried the edlebrocks and said they wrent as lage as the Accel or ASM tubes...any truths to this here?
Im just saying what I read.

As far as SLP goes...yes they can be PORTED ALOT.
Maybe they made them small and 50 state legal knowing tuners would open them anyways and make them flow a ton more air?

 

OK, outta the box the SLP arn't going to be the top dogs, no ? here.

But, for the little money you pay on them you could buy a dremel w/ flex wand & cutter bits(seperate) and dig them out much more than any other runner, plus dig out the plenum to match and match the outlets to the gaskets (as long as they match the heads..) and they will outperform any other runner. I don't have numbers or evedidence, but they must by laws of....

Plus you could cut the divider down as far as you wish. A extruded runner you can't do anything with.

 

Can someone tell me why ASM,s runner are longer than stock while all the others are shorter.

 

They probably wanted to extend the RPM range. I heard outta the box ASM are the best. The longer runner would mean no tradeoff in bottom end, the bigger cross-section would mean a higher ceiling also.

 

I have had both AS&M on my vett and the SLP's on my supercharged Z28. I noticed about the same difference. The SLP's are much cheaper and a better bang for the buck, however, I'm sure AS&M's product is a well researched animal. Personally, I would go with the slp's because from my exp. Not a whole lot of difference between the two. And You can port the crap out of the slp runners and match them to the plentum I went from 13.4 to a 12.8 with the addtion of the slp runners, porting my plentumn, and the addition of the 1.6 roller rockers.

 

Can someone tell me for what reason would I want to go with ASM,s long tube regular runners,or why would I want to go with the siamese runners. I really have no plans on changing the heads on the car. But do want to improve the intake system.Thanks for any info.

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SLP 1 5/8 Headers,ATR catback exhaust,SLP cold air box,Crane 1:6 roller rockers,Bosch plugs and MSD wires,MSD Coil,Fastchip,Borg Warner 9 bolt 3:27,Corvette Servo,ROH ZS 17X9.5 Goodyear GSC,s 275/40/17

 

From what I understand, the semi-siamesed ones are good for bigger displacement (like 383) or 350's with bigger cam and heads which like to rpm a little more.
I would stick with the regular LTR setup, that's what I did.

Bob

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350 TPI, 700R4(rebuilt), K&N's, MSD 6AL, Headers, Flowmaster, 160* stat, airfoil, MAF screens cut out. 13.88 @ 101.18 mph