Mega-ported SLP vs. SuperRam
Thread Starter
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
Mega-ported SLP vs. SuperRam
According to StealthRam.com:
stock runner length is 11.25"
stock manifold has 8" runners, total = 25.25 (with heads).
Accel runner length is also 8".
SuperRam runners are listed as 7", total = 21" (with heads).
Accel runner @ 8" with
SLP runners mega-ported (removing about 3" of 11" length) = 8"
The total runner length for the last option is about 22". And, the cross section is nearly as large as the SuperRam.
My question is would the mega-ported SLP setup (as shown on CorvettePlenum.com) perform about the same as a SuperRam?
From my perspective, it should be close because the increase in cross-sectional area is about the same and the decrease in runner-length is about the same.
I would expect a slightly lower torque number with much better top end.
Agree or not?
gp
stock runner length is 11.25"
stock manifold has 8" runners, total = 25.25 (with heads).
Accel runner length is also 8".
SuperRam runners are listed as 7", total = 21" (with heads).
Accel runner @ 8" with
SLP runners mega-ported (removing about 3" of 11" length) = 8"
The total runner length for the last option is about 22". And, the cross section is nearly as large as the SuperRam.
My question is would the mega-ported SLP setup (as shown on CorvettePlenum.com) perform about the same as a SuperRam?
From my perspective, it should be close because the increase in cross-sectional area is about the same and the decrease in runner-length is about the same.
I would expect a slightly lower torque number with much better top end.
Agree or not?
gp
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Was thinking about it the other day after seeing more pics of dagrumps piece and I bet it would be very close. In fact Id rather have a TPI setup like that than deal with a superram.
Safety Car
Joined: Jan 2006
Posts: 3,566
Likes: 4
From: Mt Laurel NJ
St. Jude Donor '06-'07
Gregg,
You should check out the FIRST intake manifold. There is a group purchase being organized, much better value then the Super Ram or a set of SLP runners w/ a high flow base.
Randy
You should check out the FIRST intake manifold. There is a group purchase being organized, much better value then the Super Ram or a set of SLP runners w/ a high flow base.
Randy
Racer
Joined: Jul 2007
Posts: 462
Likes: 21
From: Kansas City Missouri
Saw the FIRST intake thing here the other day. Very interesting. I don't really like the looks of the SLP runners as compared to stock. I like the look of the individual runners much better.
I just can't see getting rid of low end torque just to gain some more HP at the extreme RPM range, especially when most of us here run stop light to stop light. Would porting the plenum and going with the mega-ported SLP runners really be a noticeable difference down low or would the fact that you just keep the car in the higher RPM range make up the difference? In other words, you get into the high RPM really quickly anyways, so would there really be all that noticeable of a difference? Is it worth the low end loss to gain the high end HP?
You know--for what it cost to put this together, I am not too sure the used procharger wouldn't be the best option. I have seen two in the last 5 months for for less than $2000.00. Bolt it on, tune and be done with it. Plus you would still have the stock engine with reliability. I don't think you could hardly beat it.----oh yeah--no power loss down low!!!
I just can't see getting rid of low end torque just to gain some more HP at the extreme RPM range, especially when most of us here run stop light to stop light. Would porting the plenum and going with the mega-ported SLP runners really be a noticeable difference down low or would the fact that you just keep the car in the higher RPM range make up the difference? In other words, you get into the high RPM really quickly anyways, so would there really be all that noticeable of a difference? Is it worth the low end loss to gain the high end HP?
You know--for what it cost to put this together, I am not too sure the used procharger wouldn't be the best option. I have seen two in the last 5 months for for less than $2000.00. Bolt it on, tune and be done with it. Plus you would still have the stock engine with reliability. I don't think you could hardly beat it.----oh yeah--no power loss down low!!!
Last edited by Bensons86; Nov 25, 2007 at 12:20 AM.
Instructor
Joined: Nov 2005
Posts: 210
Likes: 0
From: fall river MA
i like the look of the slp's myself. i know alot of people have their opinions about ltr setups. but their are some really fast tpi cars out there. i have my slp's off the car right now,i should go have them flowed to do a comparision test against other ltr's. i'm just about done porting my accel base. lots of hours in it, and to me very enjoyable. if anyone can post pics of the base for me , i'll email them to you.
Le Mans Master
Joined: Jun 2006
Posts: 5,642
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From: One day you're a Comet...the next day you're dust... Arkansas
I'd port the hell out of the stock plenum and runners and do a heads/cam upgrade. The right combo will really increase performance. Just doing an intake is not very productive.
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Le Mans Master
Joined: Sep 2005
Posts: 6,551
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From: Jenks OK
Dang Dagrump, the weight savings from all that porting alone will make the car feel faster. 
I like the long tube setup as well, it looks like a lot can be done with the runners and base in terms of opening up extra flow and power without losing the low end grunt. My question is how much is actually lost in the runners versus the base. When does it become necessary to siamese/port the runners?
I like the long tube setup as well, it looks like a lot can be done with the runners and base in terms of opening up extra flow and power without losing the low end grunt. My question is how much is actually lost in the runners versus the base. When does it become necessary to siamese/port the runners?
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
According to StealthRam.com:
stock runner length is 11.25"
stock manifold has 8" runners, total = 25.25 (with heads).
Accel runner length is also 8".
SuperRam runners are listed as 7", total = 21" (with heads).
Accel runner @ 8" with
SLP runners mega-ported (removing about 3" of 11" length) = 8"
The total runner length for the last option is about 22". And,
the cross section is nearly as large as the SuperRam.
stock runner length is 11.25"
stock manifold has 8" runners, total = 25.25 (with heads).
Accel runner length is also 8".
SuperRam runners are listed as 7", total = 21" (with heads).
Accel runner @ 8" with
SLP runners mega-ported (removing about 3" of 11" length) = 8"
The total runner length for the last option is about 22". And,
the cross section is nearly as large as the SuperRam.
The information at StealthRam comes from posts made by grumpyvette.
He made contributions here and elsewhere like the following ones from
2003 - long before StealthRam.com came into existence.
http://forums.corvetteforum.com/show...post1544717024
http://forums.corvetteforum.com/show...post1544568309
I'm not sure how grumpyvette measured his LPE/Accel base and
runners but I can say with certainty that if the length is
measured roughly along the center of the port diameter, the
numbers are shorter than those shown at StealthRam.
Actual SuperRam Runner lengths
6.5": Base
5.5": Runner
6.0": Head
The numbers above are quick, rough measurements with a tape.5.5": Runner
6.0": Head
Interestingly, the number above of 6.5" is close to the 6.125" value
listed for the Accel base near the top of grumpyvette's intake
dimension comparison. However, for some reason the numbers at
the bottom of the comparison list the Accel base at 8.0" - this is
simply wrong.
The intake comparison was ambitious and novel. I think that much
of the information and discussion is valuable. Unfortunately the
SR data shown does not reflect lengths of the actual parts.
.
Drifting
Joined: Oct 2006
Posts: 1,554
Likes: 13
From: Romeoville IL
There is more to flow than just runner length. You have a change in plenum volume and shape creating different flow characteristics. Even if you siamese the runners to the same length as a superram, I'd bet you'd still see different power characteristics.
Drifting
Joined: Feb 2003
Posts: 1,978
Likes: 2
From: San Antonio Texas
There was a post on here a few years ago from a hot-rodders magazine that tested different manifolds. As best as I can remember the siamezed tubes on a good manifold, did not perform as well as the SuperRam. There's also comparisons in the back of my old TPIS catalog; possibly on their site.
Instructor
Joined: Jul 2006
Posts: 150
Likes: 2
Mike here from Corvetteplenum.com. With the Mega-Ported SLP's and plenum I like to think you come very close to Super-ram performance with out the PITA of dealing with the Super-ram. AND, for the record, You do NOT lose any low end torque with my Mega-Ported set-up. If anything you gain a bit. I am on my 8th TPI car and I own 3 now. The ones with the Mega-Porting, I have trouble keeping tires on those.
Drifting
Joined: Jun 2001
Posts: 1,704
Likes: 459
From: Mass Mass
Here is a good comparision, from an old article, of what your talking about
Full article here:
http://www.compcams.com/Community/Ar...?ID=1737510521
Full article here:
http://www.compcams.com/Community/Ar...?ID=1737510521
Thread Starter
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
Claims from manufacturers and people who've done the swap say the improvement is comparable to adding headers -- from 15-30HP depending on which pieces you pick (intake/runners/brand).
This seems no less productive than putting headers on a car and the price is similar.
Gregg
This seems no less productive than putting headers on a car and the price is similar.
Gregg
