Superram Vs. LT Runners on L98
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,261
Likes: 4
From: Middle River MD
Superram Vs. LT Runners on L98
I was just wondering what h.p. increase I can expect from just a switch from my current AS&M runner setup to the full Superram. See signature for current setup.
Drifting
Joined: Feb 2002
Posts: 1,937
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From: Arvada CO
Re: Superram Vs. LT Runners on L98 (HeeHaw89)
i think you see alot more topend from what i have heard my friends pulls hard he has ported plenum, as&m runners and tpis intake big mouth and then he went to the super ram it felt like a LS1 on the topend?
Melting Slicks
Joined: Jan 2003
Posts: 2,167
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From: What did the 5 fingers say to the face? SLAP!!
Re: Superram Vs. LT Runners on L98 (HeeHaw89)
If you sell the runners, let me know :D Your thinking as far as mods go is pretty much the same as mine. I have about most of the 80% of the stuff you have. Just missing the converter and 2149's(hopefully not for long) Have you ever dyno'd the car? Any guestimates?
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,261
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From: Middle River MD
Re: Superram Vs. LT Runners on L98 (dgoodhue)
IMO about 25-30hp
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 109
From: Austin Texas
Re: Superram Vs. LT Runners on L98 (HeeHaw89)
If you siamesed the base about 2.5"-3" in you would gain those RPM's you are looking for.
I did it on mine, and it now pulls like a train.... HARD..... starting around 3300 RPM and goes well past 5500 RPM to around 5900 RPM before I can feel it start to run out of breath. Of course it pulled pretty hard with 500 lb/ft before too :lol: but it pulls a lot further up into the RPM range.
As soon as we get the chip re-tuned it is going back to the dyno to see how well it worked. According to the F-body guys the siamesed base is good for about 20 HP and raises the HP/TQ curve around 900 RPM. They have some pretty empirical data doing incremental changes and dyno testing it every step of the way.
I want to optimize the TPI LTR setup and maybe a few years down the road change it over to a S/R and see what I gain. Gotta admit that it gives people something to look at when I open the hood and it is "just" a TPI motor.
I did it on mine, and it now pulls like a train.... HARD..... starting around 3300 RPM and goes well past 5500 RPM to around 5900 RPM before I can feel it start to run out of breath. Of course it pulled pretty hard with 500 lb/ft before too :lol: but it pulls a lot further up into the RPM range.
As soon as we get the chip re-tuned it is going back to the dyno to see how well it worked. According to the F-body guys the siamesed base is good for about 20 HP and raises the HP/TQ curve around 900 RPM. They have some pretty empirical data doing incremental changes and dyno testing it every step of the way.
I want to optimize the TPI LTR setup and maybe a few years down the road change it over to a S/R and see what I gain. Gotta admit that it gives people something to look at when I open the hood and it is "just" a TPI motor.
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,261
Likes: 4
From: Middle River MD
Re: Superram Vs. LT Runners on L98 (Joe90)
Wish I would have thought about siamesing before putting this together. Did you siamese the base yourself? Do you have the just the LT runners or are they the siamesed ones as well? One of the main reasons I didn't go with the superram was that I wanted to keep the stock appearance of the tpi. I'm looking for that same reaction when I blow someone away or put down some good numbers at the track. "Just" a tpi?
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 109
From: Austin Texas
Re: Superram Vs. LT Runners on L98 (HeeHaw89)
I siamesed it with a little help from a friend of mine. He has a Bridgeport mill in his garage. We used it to cut the passage, then I used air die-grinders to smooth everything up...you know...knife-edge the passage walls and smooth the casting flash from the intake runners.
I've got the completely stock-appearing AS&M big-tube runners on mine.
Check it out....
[Modified by Joe90, 6:06 PM 2/5/2003]
I've got the completely stock-appearing AS&M big-tube runners on mine.
Check it out....
[Modified by Joe90, 6:06 PM 2/5/2003]
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Instructor
Joined: Sep 2002
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From: Denver CO
Re: Superram Vs. LT Runners on L98 (Joe90)
It is interesting that such a big gain in rpm range is found from siamese ports on the base only. The air flows separately down the runners, then suddenly it finds a hole where it can flow to either of 2 ports to the intake valve? Weird. I don't doubt that it works. But it seems like siamese runners would add to the effect. Having the large volume runner all the way to the base where they split would seem to be better. The siamese runner would almost just be added "plenum" volume. It would essentially create an intake with a runner length of about 5" instead of the 12"-14" you get with the separate runners.
Have any insight as to why this simase base with separate runners works so well? Anyone tried it with siamese runners?
Thanks
Have any insight as to why this simase base with separate runners works so well? Anyone tried it with siamese runners?
Thanks
Safety Car
Joined: Feb 2000
Posts: 4,564
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From: Austin Texas
Re: Superram Vs. LT Runners on L98 (Ken Lanham)
Thanks MrNuke...
Ken, my guess would be that the siamesed runners would not work as well. The whole TPI design is centered around the velocity of the airflow through the system. Siamesed runners, because of the volume, would have a lower airspeed.
The siamesed base still gives you the velocity, but it gives you 2 runners worth of air to feed the cylinder. I'm not an engineer, but I have studied the TPI system and have (I think) maximized it as far as you can go. I've not seen any other TPI N/A cars on the forum with the kind of numbers I'm getting from this "little" 355. You need to step into the 383's to get comparable HP/TQ figures.
Ken, my guess would be that the siamesed runners would not work as well. The whole TPI design is centered around the velocity of the airflow through the system. Siamesed runners, because of the volume, would have a lower airspeed.
The siamesed base still gives you the velocity, but it gives you 2 runners worth of air to feed the cylinder. I'm not an engineer, but I have studied the TPI system and have (I think) maximized it as far as you can go. I've not seen any other TPI N/A cars on the forum with the kind of numbers I'm getting from this "little" 355. You need to step into the 383's to get comparable HP/TQ figures.
6th Gear
Joined: Jan 2003
Posts: 6
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From: Deerfield Beach Florida
Re: Superram Vs. LT Runners on L98 (HeeHaw89)
Befor going to the super ram take a look at the modified STELTH that fits C4 application With NEW fabricated Plenum. Posted under engine mods and C4tech performance
Instructor
Joined: Sep 2002
Posts: 159
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From: Denver CO
Re: Superram Vs. LT Runners on L98 (Joe90)
Joe90,
Interesting indeed. I hadn't heard of this port arrangement before. Kinda like having an X-pipe in the intake stream between the pairs of runners. I'll have to give it a try sometime.
-Ken
Interesting indeed. I hadn't heard of this port arrangement before. Kinda like having an X-pipe in the intake stream between the pairs of runners. I'll have to give it a try sometime.
-Ken
Instructor
Joined: Aug 2002
Posts: 184
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From: Philadelphia MO
Re: Superram Vs. LT Runners on L98 (Joe90)
If you siamesed the base about 2.5"-3" in you would gain those RPM's you are looking for.
Team Owner
Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: Superram Vs. LT Runners on L98 (Black88Vette)
I hope I don't sound to stupid here, but could someone tell me what "siamesed" on heads means? Thanx. :steering:
From my limited knowlegde.. I'd say that siamesing the base, even with stock runners would affect the resonance in the intake... and allow each cylinder to be fed air by two runners instead of one. A cylinder can affect the one next to it... effectively stealing it's air. Apparently this can be a problem on the #5 and #7 cylinders since they're next to each other, and sequential in the firing order.
