Those siamesed runners....are they really worth getting for a 305 TPI with the mods listed in my sig? Just curious what I should expect from them if anything. On a side note, I'm putting the Hooker 2055's on relatively soon as well.

 

TTT

 

GM High Tech magazine just put some on their 305tpi 5 speed and got like 5hp and 7ft/lbs but it was all the way across the band. You may get more because of your cam, but not much. If the base is ported or aftermarket it is well more worth it. I found my runners in the classifieds for 125 shipped. Check the listings. I always see them there for less than 200. This makes it a little more worth it as well.

 

Thanks for the information...thats exactly what I needed to know. I will do my headers first and maybe afterwards i will decide to go ahead and look for a set of thoes runners. The base is stock, hasnt been ported, so I dont know. Just thought it might be a quick, relatively simple and helpful little mod...not sure if its worth it if i wont really feel it much.

 

I would do it. 5 RWHP throughout the powerband is great! Like others have said - don't focus on "peak power", focus on "average power".

 

There is just a couple things left I need to know about these runners. First, someone on this board is selling them for $200 i believe(I forgot the username)....but he's advertising the runners WITHOUT cold start valve. What exactly does that mean? I believe my car has a cold start valve....so these runners would be for a car WITHOUT a cold start valve? Second, to install these, its relatively easy, right? Can do one side at a time, take the old one off, put the new one on? Bolt-on? Thanks everyone.

 

I think you mean cold sart injector?

200 is a fair price for siamesed runners if their SLP's. Not for stock ones tho. If your system has a 9th injector you can use the runners if they have the opening for it. Otherwise you cant. You will need runners from year 85-88 only. After that the cold start injector was eliminated. You should be able to remove one side at a time. You will probably need new gaskets as well. Siamesed runners will help you some if they are siamesed approx 2 inches. This theoretically "shortens" the runner length as far as air flow is concerned.

Just noticed this is my 100th post!! I am a senior member now. Wahoo! Does this mean I am an old man? Do I get any "senior" discounts from board sponsors?

 

200 is definetly a fair price...no arguing that. I just wasnt clear on the cold start part. Reading it again, the add said "without cold start injector". I'm assuming then these runners would not work for my setup, since my TA is an 86 WS6, and that year HAD the cold start injector......(booo hisss)....and they are SLP's also...will have to look around more...

 

I think you can elminate your cold start injector. I'm not sure, but I believe the prom can be edited to delete the function and the injector nook can be plugged or whatnot.

Don't despair until you verify that there is no way.

 

I'd like to do this without having to edit the prom or making any other changes to the setup like eliminating the cold start injector.

 

yes i meant the runners are for cars without the cold start valve.

 

There you are....yea, unfortunetly, my car has the cold start valve. I'm assuming these runners are available somewhere for cars with the cold start injector?

 

yes SLP makes a set with the hole for the CSI. but i'm also guessing ppl have deleted theirs without any problems. mine dont have one so i dunno how the car would run cold without a CSI.

 

Yea, i realize that now...just visited SLP's site. Thanks for the information...its much appreciated.

 

Sounds like you're getting answers, but here's what I understand;

As far as the CSI is concerned, it can easily be eliminated. Accel makes a kit to do so in fact (mrgasket.com). For the runners, based on the flow characteristics, they will have a lower flow VELOCITY on the bottom end, what that means is you'll be sacrificing torque. If you've got a fair amount of "lump" in your cam then the increased VOLUME they flow on the top end will compliment it wonderfully. So it comes to what you want the car to do - pull hard or scream top end. I think a good comprimise would be large tube runners; I think they maintain velocity a little better on the bottom end, yet out-flow original ones by FAR on top, but won't flow like the siamesed guys.

Any corrections, anyone? Please let me know if I'm off base here

 

The cam I have installed is good for low end torque. 1,000-4,000rpm range which is perfect for a daily driver 305 TPI from what I was told. The car doesnt see much driving @ over 110mph....ususally on the interstates, i'll hit 90-110 SOMETIMES..and it still pulls....but mainly, I want a good streetable car that pulls hard...and sometimes to drag race @ the track.

 

Then your best bet is to get with a pair with larger tubes, or simply modify your existing ones because of the cam you've got and it is a 305. I just did a little gasket matching with the entire TPI system (TB, Plenum, Runners, Intake Base) on my 305. It suffered out of the hole because of my cam, but was pretty nuts on the top end - my cam was too lumpy so it was a bit mismatched, but it pulled STRONG between 2800 and 5500+ for such a small motor. That's my advice, I doubt you'd be happy with the siamesed with a cam like that in a 305.

EDIT; Not much driving over 110mph? C'mon man! That's where the fun starts! The fastest I took mine up to was 147mph... then I ran out of road - I had to use a "speed calculator" on my PC and input my rpm, tire size, gear ratios, etc. because my speedo doesn't go that high!

 

I'll take that into consideration....I just want the car to PULL like a **** from when I hit the gas. Where would be a good place to look for larger tubes? A set, including gaskets, etc...and what kind of hp/tq #'s should expect vs. the already stated above 5hp/7ft lbs. with the siamesed runners?

This contradicts your(tpiroc) statement, and confuses me as to which is better for my setup...thats why i asked which gives me more HP/TQ gain and what would be best for me.


Fastest i've ever had her up to was 115....and thats when she was stock. After the next mods-headers, runners, valve springs- i'll see what she does....just need to borrow someone's radar/laser detector

 

TTT

 

TTT

 

It's not specified WHERE the GM Tech car made those gains. In fact, since it's noted that the 7ft/lb came "all the way across the band" means it eventually did buzzed up high enough to flow - NOT throughout the band - by the time you even thouch that measly 7ft/lb of torque, you're out of the hole, and about where your cam falls flat. 90form305tpi posted that comment about it working well with your cam before you stated it was for an idle-4k powerband; a lot of people misunderstand cam degree specs and what kind of power it makes and where.

 

So siamesed runners are worthless to me then, and larger tubes are better? <----and where would I get larger tubes from?

 

TTT

 

TPIS or Arizona Speed and Marine sells large tube runners. Look to pay out the wazoo for them though!

If I were you, I would just get the SLP's. Then remove the Cold start injector and cap off fuel rail. Then use a PROM/Memcal from and 89 IROC and you will notice a performance increase.

Then port-match your plenum and runners to a set of TPIS big-mouth gaskets for a little more power.

But, that's just what I would do...........

 

I'm trying to just do a couple extra little upgrades to my 305 before I throw a 350 in there b/c I'm not quite sure yet when the 350 project will start. I just want a bit more power relatively cheaply before I go absolutely insane with the 350 I'm planning. So i think i'm going to just add an airfoil, do the simaesed runners, and the headers, and maybe burn my own prom. Thanks for all the info and help though. I appreciate it.

 

the runners i have for sale are already fully siamesed and matched to the TPIS gaskets.