How to install Dorman Ls2 intake.
#1
How to install Dorman Ls2 intake.
Alright guys this is my first ever write up so bare with me. Hope it helps someone out that wants to install this new style intake on their 98-02 fbody.
The dorman ls2 intake is the newest ls intake offered by Dorman and so far it seems promising. Without a doubt an improvement over the original ls1 intake. When the runners are smoothed out even more so. I ordered one and eagerly awaited its arrival. However as I soon found out. It wasnt direct fit. I will cover each issue I ran into.
MAP SENSORS
For the 98-02 f body the map sensor mounts in the rear. The dorman unit has a hole in the back that needs to be drilled for this. I suppose you could move your map sensor to the front but why? I originally had to use a 1 3/8 freeze plug to fill the hole in the front top of the intake. Later I found out the egr block off plug the ws6store sells worked and looks 10x better. Heres the link to their block off. http://www.ws6project.com/user_stor/...oducts_id=4789
This is the ls2 map sensor location.
HVAC CONTROLS
Also on the back there is no nipple for the hvac controls. You have a few options. T into the brake booster hose or tap the intake and add a fitting. I did the latter. I used a 7/16 drill bit and drilled the already existant hole that is there for when the bottom is used on the ls6 intake. I then tapped it for 1/4 npt and threaded in a brass fitting.
STEAM VENTS
Ls1 steam tubes will not clear the underside as with most low profile intakes so the typical massaging and flattening them is required. I used a vice to slowly flatten the tubes until they cleared. Some use a hammer but I felt that was too risky. Didnt want to smash the tube closed.
THROTTLE BODY
I went with a Warr Performance 92mm unit to match the the intake. This is a quality piece as far as I can tell. Veteran owned company with great customer service. The fitment is good except for the fact the throttle rotor will contact the intake manifold and only allow it to open about half way. I made a notch in the manifold and it clears fine. The other issue I had with this throttle body was that the throttle cable would not fit into the rotor. A 5/16 drill bit fixed that easily.
EVAP & EGR
I previously deleted my evap system so I cannot attest to this but I see no reason it wouldnt work. My egr has already been deleted as well but looks like it should work. Maybe someone can chime in on this.
FUEL RAIL
Ls1/6 rail fits like oem. Ls2 requires hardware included with the intake.
WATER PUMP CLEARANCE
As with most big tb intakes in combination with the ls1 water pump some grinding and clearancing is required.
THROTTLE CABLE BRACKET
The intake comes supplied with square nuts that allow you to swap your ls1 or ls6 bracket over effortlessly.
KNOCK SENSORS
Also just wanted to add that if your car is a 98 now is a good time to upgrade the knock sensors and harness. The oem sensors in the 97-98 ls1's were way too sensitive and pulled timing as a result.
BELLOW
I tried to use my SLP style smooth bellow but the throttle body now sits about an inch farther forward. You would have to trim the traditional smooth bellow down or use an oem accordian style. It took some effort but the original bellows fits perfectly.
One last thing I would recommend smoothing out the intake runners where the two piece intake is glued together if you can. Dont enlarge it just smooth out the transition.
Overall impression is the car pulls harder up top. I went from the ls1 intake manifold with a ported tb to this setup. Plus swapped out bad knock sensors so that was probably worth a few hp also. So there you go it wasnt a hard swap just tedious.
The dorman ls2 intake is the newest ls intake offered by Dorman and so far it seems promising. Without a doubt an improvement over the original ls1 intake. When the runners are smoothed out even more so. I ordered one and eagerly awaited its arrival. However as I soon found out. It wasnt direct fit. I will cover each issue I ran into.
MAP SENSORS
For the 98-02 f body the map sensor mounts in the rear. The dorman unit has a hole in the back that needs to be drilled for this. I suppose you could move your map sensor to the front but why? I originally had to use a 1 3/8 freeze plug to fill the hole in the front top of the intake. Later I found out the egr block off plug the ws6store sells worked and looks 10x better. Heres the link to their block off. http://www.ws6project.com/user_stor/...oducts_id=4789
This is the ls2 map sensor location.
HVAC CONTROLS
Also on the back there is no nipple for the hvac controls. You have a few options. T into the brake booster hose or tap the intake and add a fitting. I did the latter. I used a 7/16 drill bit and drilled the already existant hole that is there for when the bottom is used on the ls6 intake. I then tapped it for 1/4 npt and threaded in a brass fitting.
STEAM VENTS
Ls1 steam tubes will not clear the underside as with most low profile intakes so the typical massaging and flattening them is required. I used a vice to slowly flatten the tubes until they cleared. Some use a hammer but I felt that was too risky. Didnt want to smash the tube closed.
THROTTLE BODY
I went with a Warr Performance 92mm unit to match the the intake. This is a quality piece as far as I can tell. Veteran owned company with great customer service. The fitment is good except for the fact the throttle rotor will contact the intake manifold and only allow it to open about half way. I made a notch in the manifold and it clears fine. The other issue I had with this throttle body was that the throttle cable would not fit into the rotor. A 5/16 drill bit fixed that easily.
EVAP & EGR
I previously deleted my evap system so I cannot attest to this but I see no reason it wouldnt work. My egr has already been deleted as well but looks like it should work. Maybe someone can chime in on this.
FUEL RAIL
Ls1/6 rail fits like oem. Ls2 requires hardware included with the intake.
WATER PUMP CLEARANCE
As with most big tb intakes in combination with the ls1 water pump some grinding and clearancing is required.
THROTTLE CABLE BRACKET
The intake comes supplied with square nuts that allow you to swap your ls1 or ls6 bracket over effortlessly.
KNOCK SENSORS
Also just wanted to add that if your car is a 98 now is a good time to upgrade the knock sensors and harness. The oem sensors in the 97-98 ls1's were way too sensitive and pulled timing as a result.
BELLOW
I tried to use my SLP style smooth bellow but the throttle body now sits about an inch farther forward. You would have to trim the traditional smooth bellow down or use an oem accordian style. It took some effort but the original bellows fits perfectly.
One last thing I would recommend smoothing out the intake runners where the two piece intake is glued together if you can. Dont enlarge it just smooth out the transition.
Overall impression is the car pulls harder up top. I went from the ls1 intake manifold with a ported tb to this setup. Plus swapped out bad knock sensors so that was probably worth a few hp also. So there you go it wasnt a hard swap just tedious.
Last edited by Zach-R; 05-22-2017 at 07:17 AM. Reason: Update.
#5
#6
I attempted to have the crack welded but he ended up ruining the steam tubes lol. In the end I ordered a real nice looking AN and braided hose setup. I do show the car a few times a year so a little extra bling never hurts.
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#8
I finally got to the point of fitting my intake and WARR 92mm throttle body. Luckly my throttle cam clears the intake at WOT. I will be re-routing my rear vent tubes around the outside of the intake manifold. I didn't not check the clearance between the waterpump and tb yet.
#10
I bought some 5/16" high temp hose and routed the two vent ports around the intake manifold.
For the small vac line, I drilled a hole into the brake booster line and reused a line that went to the AIR pump (disconnected long ago).
Notice I doubled the hose clamps on the rear driverside port. For some reason the tubing is 1/4" on this one.
#13
#15
#18
Update: The ws6 store egr block offs meant for the ls1 intakes work on the dorman ls2. Its a much better looking alternative to the expansion plug.
Here's a link. http://www.ws6project.com/user_stor/...oducts_id=4789
Here's a link. http://www.ws6project.com/user_stor/...oducts_id=4789
#19
So is this any improvement over an ls6 intake? Has anyone tested it on the dyno?
I know that out of the box the ls2 intake despite the bigger throttle body inlet made less power than the ls6 with a 78mm tb.
I know that out of the box the ls2 intake despite the bigger throttle body inlet made less power than the ls6 with a 78mm tb.
#20
Its only been flow bench tested but it did well. It was tested unported also. This isnt a normal ls2 intake it uses a fast bottom half and dormans upper that flows much better than the oem ls2.
Last edited by Zach-R; 05-24-2017 at 02:44 PM.