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There was a lot of disappoint in the LS world when the OEM LS2 90mm intake manifold didn't live up to expectations. Basically. in NA applications the OEM LS2 intake doesn't preform as well as the older LS6 intake with a small TB opening. This has been shown on the flow bench and in dyno testing. One theory is the sonic welding used for the OEM LS2 allows internal leaking betwen runners which hurts overall flow. The LS6 while the better intake is hurt by the small TB opening. The TPiS 90mm snout on an LS6 gains hp compared to a stock LS6 intake.
The Dorman may be best described as a LS6 style top half mated to a FAST 92 lower half with a 92mm snout. The intake released last week and mine arrived from Rock Auto today. The price was $354 with discount code $337, ground shipping $7. Other chains like Autozone can order these as well and quoted a price of about $440. It might be possible to get a price match, I don't know.
The Dorman LS2 comes install instructions, install hardware, gaskets installed on the intake, intake and new o-rings for the fuel injectors. The intake appears OEM quality and well made. The top of the intake says Made in the USA and lists the torque spec's for the bolts. The MAP sensor can be mounted at the back or above in the snout where the EGR fitting was located on some early LS1 engines. The snout opening appears to be right at 92mm. There is a tiny amount of flash that can be removed. Inside the intake appears well made. I will try to add more pictures later.
I suspect the $354 LSD2 will preform close to the level of a $849 Fast 92. Combine the LSD2 with a $139 92mm throttle body from WARR for a bargin LS1/LS2/LS6 upgrade.
I plan to have my Dorman flow tested next week with a set of Lingenfelter ported Stage 2 243 heads. I will update when I have results.
The Fast can be taken apart for porting unlike the LSD2. The LSD2 could also be ported to some degree but doesn't seem to allow as much access internally.
Stock Dorman photo Install kit w/intake. Stock photo. Fresh out of the box today. 92mm snout Rear Peak Performance or other porter could probably improve bottom of runner but it looks decent out of the box.
LSD2 & WARR 92mm TB mocked up.
WARR TB bolted right up and appears to match nearly flush inside TB and intake snout MAP can be mounted on top or at rear. Note fit inside is almost flush WARR TB will need IAC & TPS sensors. Blade fits nicely and operates smoothly. While I haven't used a WARR TB yet I will try this one at some point. Will loctite TB blade screws in place before using.
It is hard to tell in the pics, but does the snout allow for the use of both the three and four bolt throttle body??? If so, that would be awesome!
I hope it works as good as it looks so far. The price of any ls car intakes are not getting any cheaper... perhaps this will bring down the prices for at least stock pieces.
Cosmetically, I think they went a little heavy with all the stamps on top like that.
If it works the way you think it will I'm sure that's of little concern.
Ron, thank you.
I think you are perfectly correct that they went a little crazy with stamps & torque values on top of the intake. Most of those may have to be sanded off & then re-painted.
I guess they felt like not everyone would read the instructions.
Very cool. What about the MAP sensor? Do you have to drill it's mounting location?
The MAP can be mounted two different ways. 1) at rear which I think requies drilling 2) on top of snout where EGR went of LS1 intakes. I don't have the instructions with me at the moment but they do go into detail on mounting the MAP sensor.
My plan to get the LS2D intake flow tested this week with LPE S2 243 heads has turned out to be too ambitious. My shop of choice won't be able to do the testing for several weeks. I will update when I have results. I want to have the heads tested on the same type of flow bench all of my other testing was done on and that limits my choices of shops.
Thanks to Bret at Land Speed Cylinder Heads in Indianapolis, I was able to vet the Dorman LS2 intake flow tested along with some other LS intakes I've collected. Test was at 28 inches, 4 inch bore on a calibrated SF1020 flow bench. The TBSS, Dorman LS2 & LSXRT were tested with the 92mm WARR TB in place. The TB had the blaxe zip tied open. The bare ported LS6 head was tested at the start and then at end to confirm nothing had changed during the test. Clay radius was used on the bare head. Note that all of the intake manifolds reduce airflow, I suppose its a matter of picking the best "restrictor plate" for one's own engine.
The TBSS intake is regarded as the best factory cathedral intakes. The LSXRT is almost on par in some applications to a full fleged tuned racing manifold, in some ways almost like a folded over Kinlser.
The data
I think the Dorman LS2 intake did pretty well in the flow test. It did have some flash in the bolt holes I didn't see until it was pointed out during the test. The WARR 92mm throttle body matched the intake spot on.
The LS1 fuel rail and injectors also fit nicely when I mocked them up.
I still think that this hole would allow for the use of a 3 hole TB. You might have to move the insert from one of the upper corners to use it properly.
I am disappointed that it does not come with the inserts for the throttle cable mount, but those can be obtained from a stock/broken intake.
02-15-2017, 11:39 PM
