Dorman ls2 intake?
#341
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Well you definitely sagged it at the right time and Price. Strange thing is I looked several times in September and it wasn't listed.and if look back at preceding page it will reflect the same thing. As far the price swing never saw it that high of $378 . The range I have observed was from $343 to about $317 those where without a discount.
Sadly... Months ago before I first started reading this thread RA had it list for less than the Dorman LS6 version, LS6D was listed at $292, and LS2D was $283... Wish I knew what it was a week or so earlier!
Give WS6Store a try, they might surprise you! (If I'm reading their post correctly) "Spoiler alert"...
Good hunting!
Mike
#342
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
i really wish dorman had kept the original FAST/Wilson design for the top shell instead of only using the mid and bottom shell and designing their own proprietary top shell. You'd have a larger runner volume and wouldn't have to deal with the lousy runner-to-port transition.
i'm still in for dyno and flow numbers compared to an OEM LS6 manifold.
#343
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
that's a really nice job, but it still seems you can't completely remove that "ramp" from the top of the runner to the lower shell.
i really wish dorman had kept the original FAST/Wilson design for the top shell instead of only using the mid and bottom shell and designing their own proprietary top shell. You'd have a larger runner volume and wouldn't have to deal with the lousy runner-to-port transition.
i'm still in for dyno and flow numbers compared to an OEM LS6 manifold.
i really wish dorman had kept the original FAST/Wilson design for the top shell instead of only using the mid and bottom shell and designing their own proprietary top shell. You'd have a larger runner volume and wouldn't have to deal with the lousy runner-to-port transition.
i'm still in for dyno and flow numbers compared to an OEM LS6 manifold.
I recall reading they used the FAST Bottom, the LS6 Upper, with Neck from the LS2 for the 4 bolt inlet to allow for larger TB's. That would account for the mismatch between the upper and lower... Wonder if some 320 then 600 grit wet sandpaper would really smooth out the port blending... Haven't cleaned the ports on my LS2D yet, but pictures like yours shore do inspire me to get after it!
Nice job!
Last edited by MikeyZ28SS; 10-26-2017 at 07:39 PM. Reason: Business model
#345
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Since the topic at hand is the Dorman LS2, would a nicely "warmed over" 5.3 of, say, 375-400FWHP, be needing the flow capacity of the LS2 with its larger TB capability? Or would an LS6 manifold do as well or better?
#346
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
the runner design plays a fair role in tuning for max cyl pressure at the right rpm range, and i am sure affects port velocity as well.
#347
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
OK, I can appreciate this reasoning. So maybe I should word it this way- Which manifold would work better for the 5.3 mentioned above; Dorman LS2, or LS6(OEM or Dorman)?
#348
LS1Tech Premium Sponsor
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
A higher strung 5.3 would benefit from the added volume and inlet from the Dls2.
Honestly, on a smaller engine, you wont see a huge gain unless it either greatly increases plenum volume (ala ls6 vs ls1) or your engine actually exceedes the ability of the manifold to provide the air. Longer runners in the ls world are usually larger also so it doesnt hinder top end performance as much as the old sbc tpi style did but they will promote the lower and mid range.
Normally youll see that as a dropping MAP (kpa) during a wot pull. Unloaded wont show it as much as a loaded dyno also.
I've seen ls6 manifolds drop 5kpa on the top end on "proven" combos that swear they pull the engine to 6800 and it makes power. Loaded dynos are way better for true testing but hurt feelings and egos easily.
I have not done any actual csa or runner length measurement on a dls2 so all of this is based off normal engine theory but also experience.
Honestly, on a smaller engine, you wont see a huge gain unless it either greatly increases plenum volume (ala ls6 vs ls1) or your engine actually exceedes the ability of the manifold to provide the air. Longer runners in the ls world are usually larger also so it doesnt hinder top end performance as much as the old sbc tpi style did but they will promote the lower and mid range.
Normally youll see that as a dropping MAP (kpa) during a wot pull. Unloaded wont show it as much as a loaded dyno also.
I've seen ls6 manifolds drop 5kpa on the top end on "proven" combos that swear they pull the engine to 6800 and it makes power. Loaded dynos are way better for true testing but hurt feelings and egos easily.
I have not done any actual csa or runner length measurement on a dls2 so all of this is based off normal engine theory but also experience.
#351
TECH Veteran
iTrader: (1)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Facebook Post
1) I recommend buying an intake from tech@ws6store. Very highly. I was having an issue with my install and he helped me out even though I didn’t buy my intake from him. I wish I had. We emailed back and forth probably a dozen times and he always replied within 30 minutes and I didn’t even buy the intake from him. So whether he’s a few bucks higher or not (his prices on some things I looked at were cheaper than everyone else btw) I’d recommend buying from him because the communication is second to none.
Please note, you MUST CHANGE the valley cover bolts to the lower profile bolts that come with the manifold. I had been having some serious tuning issues because of a vacuum leak I had. Tech@ws6store helped me find that problem. So be aware that you need to use the lower profile bolts or it will hit the bottom of the intake keeping it from seating.
Now for the info everyone has been waiting for. This was posted on Facebook. A guy did back to back Dyno testing of the most powerful factory cathedral port intake (trailblazer ss) you can get vs the dorman ls2. Amazingly the power curves were identical. The engine was retuned for both manifolds. And I seriously doubt the dorman was even cleaned up which I guarantee it worth several hp. This was a 5.3 with a cam. Enjoy....
Here’s the video link if you guys can pull it up.
Facebook Post
![](https://s26.postimg.org/sllv5rsop/6_CFA3_A2_C-5_D21-4468-_AAA5-3_B8_CEC91_D3_A7.png)
![](https://s26.postimg.org/9j2hiuho9/8_E152_C7_A-_C780-40_BC-_A188-_B0_A24_DD93_FCD.png)
![](https://s26.postimg.org/7d86oce7t/BEC4_FFAE-2_C0_D-46_F9-9508-_BB7_E55_EBBBE9.png)
Last edited by Kfxguy; 12-16-2017 at 03:07 PM.
#352
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Whoa! Thank you! The Dorman LS2 within a 2-3HP ALL THE WAY thru the curve(s). Same for torque! Dorman did their homework on this one, OR got REALLY lucky!
#354
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I wonder who did the test. I see a "posted by Richard" on the video screen. Richard Holdener??
#356
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I wonder if it's all for a magazine article. Super Chevy, Car Craft, Hot Rod?
#359
TECH Veteran
iTrader: (1)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Btw guys, my buddy messaged the guy and he said he’s going to test a fast intake back to back with the dorman. I wish they would do that and then do a mild clean up job on the dorman and then retest it on the same day. That would be pretty interesting. I’ve been contemplating swapping intakes for a fast but I’m not so sure I should even waste my money on it. Especially knowing I have to buy fuel rails too. My car runs exceptionally well for what I’ve got done to it and I feel like the intake has added a good bit to it.
#360
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Btw guys, my buddy messaged the guy and he said he’s going to test a fast intake back to back with the dorman. I wish they would do that and then do a mild clean up job on the dorman and then retest it on the same day. That would be pretty interesting. I’ve been contemplating swapping intakes for a fast but I’m not so sure I should even waste my money on it. Especially knowing I have to buy fuel rails too. My car runs exceptionally well for what I’ve got done to it and I feel like the intake has added a good bit to it.