intake for boosted ls2 ??
Thread Starter
Advanced
Joined: Apr 2005
Posts: 96
Likes: 14
intake for boosted ls2 ??
I know this has been beat to death. Answer is normally keep the stock one or just turn the boost up. I'm trying to squeeze some more power out of this set up.
I know i'm leaving some power on the table with the stock ls2 intake and I can't turn up the boost any further. V3 t trim with a 3.4 and 10 % and turning it to 6700ish. Car makes 795rwhp with the stock ls2.
The lsxr 102 ported was recommended to me by Tony M. But I'm super gun shy on getting another fast. I had a Fast 92 on it and it pulled the plastic ''columns'' outta the bottom and it would seal when the car pulled vacuum and then unseal when it got into boost.
I also feel the BTR intake is probably to short of a runner for what i'm doing with the car.
Port the ls2 ( does anyone even still do that)?
MSD atomic? Kind of a short runner, also said to have sealing problems
Holley Ultra low ram will fit under the hood but also another short runner intake
So where does that leave me?
I know i'm leaving some power on the table with the stock ls2 intake and I can't turn up the boost any further. V3 t trim with a 3.4 and 10 % and turning it to 6700ish. Car makes 795rwhp with the stock ls2.
The lsxr 102 ported was recommended to me by Tony M. But I'm super gun shy on getting another fast. I had a Fast 92 on it and it pulled the plastic ''columns'' outta the bottom and it would seal when the car pulled vacuum and then unseal when it got into boost.
I also feel the BTR intake is probably to short of a runner for what i'm doing with the car.
Port the ls2 ( does anyone even still do that)?
MSD atomic? Kind of a short runner, also said to have sealing problems
Holley Ultra low ram will fit under the hood but also another short runner intake
So where does that leave me?
Pro
Joined: Feb 2005
Posts: 652
Likes: 16
From: Upton MA
I had an older fast and It was not up to the task. The bottom bulged the intake ports shrunk due to vacuum and porting, also one of the brass inserts for the throttle body pulled out. I have changed over to rectangular port 102lsxr Fast, with a Nick Williams 103mm Throttlebody. I did again have one of the brass inserts for the throttle body pull out. I replaced it with a larger insert, I run 20 psi into a 427" engine 1004 rwhp 890rwtq.
Overall I am happy with the performance of the 102mm Fast, I would not recommend porting as it weakens the port at the head to manifold interface. The Nick Willams throttle body is a good piece and it works with a C5 I tried two other low cost TB's and they did not function with a C5.
Also there is a clearance problem with the back of the Fast lsxr manifold and the cowl. I lowered my engine cradle with (4) 0.200" spacer washers.
Good Luck
Overall I am happy with the performance of the 102mm Fast, I would not recommend porting as it weakens the port at the head to manifold interface. The Nick Willams throttle body is a good piece and it works with a C5 I tried two other low cost TB's and they did not function with a C5.
Also there is a clearance problem with the back of the Fast lsxr manifold and the cowl. I lowered my engine cradle with (4) 0.200" spacer washers.
Good Luck
Last edited by glennd; May 6, 2024 at 07:46 AM.
Instructor
Joined: Jun 2023
Posts: 229
Likes: 41
I had a NW 102 boost version, it never did stop throwing REP codes. On top of zero support from NW, I’d go Katech, only one I believe is actually set up for c5
Also my 102 sits about 10-12mm below the cowel, hard to install
bit nothing had to be dropped.
Also my 102 sits about 10-12mm below the cowel, hard to install
bit nothing had to be dropped.
Race Director
Joined: Dec 1999
Posts: 10,230
Likes: 885
From: Alexandria, Virginia, USA VA
The stocker will make a much flatter overall ave torq curve where the short runner manifolds help in that 6-8k range after the stocker falls off (around 6600-7000)
sacrificing some low speed torq isn't a bad thing but only if you pull upstairs enough revs to get the short runners to pay off
for street, pretty hard to beat the stocker even with the blower. You don't rev high enough with a big enough cam to run 7500+ where the short runners really pay off with HP increase
sacrificing some low speed torq isn't a bad thing but only if you pull upstairs enough revs to get the short runners to pay off
for street, pretty hard to beat the stocker even with the blower. You don't rev high enough with a big enough cam to run 7500+ where the short runners really pay off with HP increase
Thread Starter
Advanced
Joined: Apr 2005
Posts: 96
Likes: 14
I had an older fast and It was not up to the task. The bottom bulged the intake ports shrunk due to vacuum and porting, also one of the brass inserts for the throttle body pulled out. I have changed over to rectangular port 102lsxr Fast, with a Nick Williams 103mm Throttlebody. I did again have one of the brass inserts for the throttle body pull out. I replaced it with a larger insert, I run 20 psi into a 427" engine 1004 rwhp 890rwtq.
Overall I am happy with the performance of the 102mm Fast, I would not recommend porting as it weakens the port at the head to manifold interface. The Nick Willams throttle body is a good piece and it works with a C5 I tried two other low cost TB's and they did not function with a C5.
Also there is a clearance problem with the back of the Fast lsxr manifold and the cowl. I lowered my engine cradle with (4) 0.200" spscer washers.
Good Luck
Overall I am happy with the performance of the 102mm Fast, I would not recommend porting as it weakens the port at the head to manifold interface. The Nick Willams throttle body is a good piece and it works with a C5 I tried two other low cost TB's and they did not function with a C5.
Also there is a clearance problem with the back of the Fast lsxr manifold and the cowl. I lowered my engine cradle with (4) 0.200" spscer washers.
Good Luck
The stocker will make a much flatter overall ave torq curve where the short runner manifolds help in that 6-8k range after the stocker falls off (around 6600-7000)
sacrificing some low speed torq isn't a bad thing but only if you pull upstairs enough revs to get the short runners to pay off
for street, pretty hard to beat the stocker even with the blower. You don't rev high enough with a big enough cam to run 7500+ where the short runners really pay off with HP increase
sacrificing some low speed torq isn't a bad thing but only if you pull upstairs enough revs to get the short runners to pay off
for street, pretty hard to beat the stocker even with the blower. You don't rev high enough with a big enough cam to run 7500+ where the short runners really pay off with HP increase
Instructor
Joined: Jun 2023
Posts: 229
Likes: 41
My procharger and bracket are waiting for me to pin the crank, I’d maybe go ls2 mani over LSXR since procharger should make up the difference.
I wonder if a sheet metal manifold would work fine enough, the power curve seems dictated by blower rpm.
I wonder if a sheet metal manifold would work fine enough, the power curve seems dictated by blower rpm.
Race Director
Joined: Dec 1999
Posts: 10,230
Likes: 885
From: Alexandria, Virginia, USA VA
I'm pullied to max the blower spin at 7100 so I will be sticking with the stock LS3. The blower will extend the power band to that rpm with the stock intake just fine. With the big 416 and the 4" crank, 7k is a good target for max revs for a street machine
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Pro
Joined: Feb 2005
Posts: 652
Likes: 16
From: Upton MA
I have had the Fast LSXR for about a year (4K mile) . I do not race it, however it will see 20 psi every time I drive it. I have had the manifold off recently and I do not see any deformations as I did see with the older Fast. I went to the dyno with my friend yesterday he has a 416" with a stock ls1 manifold and stock throttle body. The two engines do have different heads, cam, intake etc, my engine does have the higher end components, he is running 8.5 C/R I am running 9.0 C/R both are with a D1X we make similar power however he is running 3.5 lbs higher. So it does appear to me if you want to save some money a smaller pulley can get you there.
Instructor
Joined: Feb 2024
Posts: 117
Likes: 19
From: New Jersey
A short runner would absolutely destroy the curve below 5k. Gains up top are negated by a lower overall average. Unless you're hyper competitve and trying to squeeze out every last 10th its just not worth it imo. LSXR102 destroys almost every short runner on your list even at higher rpms. And if you ever want to see what you were missing out on, the runner length is changable. The manifold is a different design than the 92, not just larger.
Burning Brakes
Joined: Nov 2018
Posts: 762
Likes: 51
My ls2 Novi1500 setup would fall on its face with the lsxr102 intake/Nw102 I hated how the car performed up top. Car made 655whp@12psi with the lsxr102. Low and mid range power was awesome and to be honest as daily that was my favorite setup. Switched to BTR Equalizer/Nw102 and moved the powerband to top end car made 678whp. Power loss was noticeable at low end and mid range but definitely was worth it for me.
Thread Starter
Advanced
Joined: Apr 2005
Posts: 96
Likes: 14
My ls2 Novi1500 setup would fall on its face with the lsxr102 intake/Nw102 I hated how the car performed up top. Car made 655whp@12psi with the lsxr102. Low and mid range power was awesome and to be honest as daily that was my favorite setup. Switched to BTR Equalizer/Nw102 and moved the powerband to top end car made 678whp. Power loss was noticeable at low end and mid range but definitely was worth it for me.
Do you have graphs of both set ups to show the loss of low end/mid range? Did boost stay the same with the intake switch?
