SLP ported/siamesed runners?
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
How important is siamese? I've never done that before.
In fact if it were me if you could not port just sell the TPI and do a LT1 intake conversion. the one in the parts section is a deal.
If you are going to port and not cut the runners open you almost have to siamese just to get your tool to the inside curve and drop the floor down even then its real hard to get noticeable material removal wihta long bit (lack of control/leverage). If you want to make a nice round bullnose with the wall separating the two runners then cut the divider out of the plenum and gasket match its a plus.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Ok...flap-wheels, grinding stones, and a handful of assorted Harbor Freight accessories....
http://forums.corvetteforum.com/1570379834-post30.html
You know...VW4Life, I might be tempted to try a free-mod (considering your cam/intake). Try to find pictures of a siamesed BASE.
Porting itself is much easier but does require removal of your intake base. Basically, you’re siamesing the top of the base tubes. In doing so, it can pull air from two runners. There is debate about this mod’s ultimate effectiveness but TPI bases are CHEAP/WORTHLESS – making the mod nearly a free mod.
As for the power potential of siamesed SLP runners, refer to the 10-times-the-Torque intake comparison article (as found online). On a cammed 383, with a large-mouth base, I’m thinking the gains for siamesing were in the 50hp range. They seemed enough for me to consider that type of intake with my build. Gains wouldn’t be as high with a 350 and stock base though.
Le Mans Master
Joined: May 2004
Posts: 5,386
Likes: 534
I agree with Cumber, the Super Ram sounds like your best bet and you can tweak it a little if you want to pull a little more rpm. I am going the miniram route in my own combo but looking back.....where are you going to wind the car up that high to benefit from the mini flow, by comparison to the instant down low/mid range fun the super gives? If you get the Super Ram now, there is still plenty of room to grow into it if you up the displacement.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
Supposedly the previous owner ported my intake and plenum, but its got the stock looking runners on it. I do NOT want to get a short ram or any other kind of ram intake right now because it would require too much additional work, like re-camming my cammed car.
I've heard reports of 20hp from the ported/Siamesed gargantuan runners. I figure that the SLP runners would work good with my current injectors and heads and cam etc.
So whats the deal w/ the SLP ported/siamesed runners... worth the $300 and 20hp (and better power curve)?
I've heard reports of 20hp from the ported/Siamesed gargantuan runners. I figure that the SLP runners would work good with my current injectors and heads and cam etc.
So whats the deal w/ the SLP ported/siamesed runners... worth the $300 and 20hp (and better power curve)?
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Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Its not going to be a big difference
If I was you and you cant do your own porting (paying someone good adds up too much) Id sell the tpi stuff and go buy one of D fredericks converted LT1 intakes put it on, done. it will run good with most any cam you throw at it and EASY to take on/off. Best bang/buck imo.
Edit: time sheets/et & mph where it counts. Dyno sheets dont mean that much lol.
If I was you and you cant do your own porting (paying someone good adds up too much) Id sell the tpi stuff and go buy one of D fredericks converted LT1 intakes put it on, done. it will run good with most any cam you throw at it and EASY to take on/off. Best bang/buck imo.
Edit: time sheets/et & mph where it counts. Dyno sheets dont mean that much lol.
Last edited by cv67; Nov 22, 2013 at 11:08 AM.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
I don't have any dyno sheets to show. I never spent any money on that. I figured I spent enough already and it runs great ! I made so many changes to the car its hard for me to give you an answer as to what gains the SLP runners made. I can say this much take some time and dremel out the aluminum at the mouth and open it up. Simple enough. I can say that these aftermarket runners make it impossible to remove the valve covers. You need to pull them off if you want to remove a valve cover.
Thread Starter
Melting Slicks
Joined: Nov 2013
Posts: 2,264
Likes: 3
From: Orchard Park NY
D Fredericks converted LT1 intakes? More info would be great.
c4: You only have stock tuning or a canned tune then? I wonder how much more custom dyno tuning would give you in your setup.
c4: You only have stock tuning or a canned tune then? I wonder how much more custom dyno tuning would give you in your setup.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
http://forums.corvetteforum.com/c4-p...ed-intake.html
hes been doing these for awhile. Maybe he can walk you through it see if it works for you. Seems like a great bang for the buck.
hes been doing these for awhile. Maybe he can walk you through it see if it works for you. Seems like a great bang for the buck.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
I have Comp Cam 08-501-8 which was recommended to me from Summit based on two things 25HP gain and compatible with my ECM. All I had to do was increase air flow to let the cam be effective and improve the exhaust. I did both. I also put roller rocker arms on and changed the injectors from 22 to 24lb. I have heard from people that a custom chip would improve the performance. Maybe someday. My reason is the car runs GREAT and I never have any negative issues with idle.
Race Director
Joined: Nov 2003
Posts: 12,221
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
There's an auto-x-er here who's running stock bin on a hotcammed 350 with TPIS intake/headers. Even has higher-than-stock compression (bottom-end). He installed 24SVO injectors and had to raise FP 7-8 lbs. He raced a whole season/two that way, built a new setup and ran it for a year, then went back.
I think he's pretty happy.
The main thing is to scan it and make sure you're not going lean on WOT. (Of course, running richer than a moonshine mill in the swamp isn't great either!)
Wait! Didn't I read where C4inMesa blew out the engine recently?
Naw...I prolly remember wrong.Seriously though...[free] software and an ALDL cable isn't a big investment to find out where you're at. I'd want that -- at a minimum even with a mail tune.
Last edited by GREGGPENN; Nov 22, 2013 at 04:32 PM.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
With a cam, he got more air. Going from 22 to 24lb injectors, he got more fuel. It helps that he's in the ballpark for parity of AFR increase.
Idle, cold operation, and WOT are the biggest "unknowns" even if you match fuel to air increases. I also mentioned 15% which could be "doable" considering minor changes.
It certainly won't be perfect, but it can be "doable". FWIW, that 15% is "+/- 15%". That actually means you have a 30% "window" to land in for acceptable operation.
For the racer in question, running with a stock chip/ECM saved points...and class of race.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
GREGG please point me in the right direction as far as getting a chip. I get the impression from your post that you think I would be better off. When I finally got m car back I called several shops here in the Mesa Phx area that dyno cars. They told me up to 2 days and $1200 minimum. I was disgusted and never looked into again. So many threads warn of mail order chips. As far as the fuel pressure is concerned it was set at 45 no more no less engine off turn the key for a couple seconds. Other than that the stock computer is adjusting fuel and air mix. If you were me what move would you make ?
Melting Slicks
Joined: Mar 2008
Posts: 2,141
Likes: 76
From: Santa Maria, CA
GREGG please point me in the right direction as far as getting a chip. I get the impression from your post that you think I would be better off. When I finally got m car back I called several shops here in the Mesa Phx area that dyno cars. They told me up to 2 days and $1200 minimum. I was disgusted and never looked into again. So many threads warn of mail order chips. As far as the fuel pressure is concerned it was set at 45 no more no less engine off turn the key for a couple seconds. Other than that the stock computer is adjusting fuel and air mix. If you were me what move would you make ?