Ok so in my last post we basically decided my Oldschool tubular manifold sucked worse than everyone said it would and was destructive to my 1/4 mile times.
With my cams, .340I/.350E lift and 210 at 50 duration which compared to the stock 2.4 cams the lift is slightly less on the intake, approx .014, it has 12 degrees more duration at 50. As for the exhaust it has .005 more lift with 21 more degrees duration at 50, Which manifold would be better? My options are LO manifold, HO manifold, Or to modify one of those OBX Venom knock offs, since the head has been matched to the 2.3 manifold. I think the skinnier runners of the LO would be better for the low lift but The larger Plenum of the HO would be good for the up top and the longer duration. Also the OBX manifold has fatter than stock runners. I also have an HO manifold setup to run a 70mm throttle body and throttle body to match. I think that might be too much for this setup and might be using it for my other build if I dont go the ITB direction.
Basically I listened to no one the first time around testing my theories and was wrong. So this time around id like to hear everyones opinion and take the advice on the manifold.
throw the OBX in the river, its worse than junk.
id go try a LO then go to HO just for testing purposes. but i think LO will be best.
Underdog Racing
Yeah thats the direction im leaning, thanks for the input
Screaming for Mercy!! wrote:I would go stock.
I have considered that but I already modded the ports to work with the 2.3 manifold and Im not sure the gasket will sine up anymore.
personally i have experienced better 1/4 mile times on auto 2.4s with the LO manifold....so thats my advice
try them all if you have time and money to track test them
personally i say HO mani with HO cams...
Whichever one I go with, probably LO, I will definitely get track times. The only thing I plan on changing is the manifold for now. Although this engine will make its way into my vert once tax return time comes around Ill be going full force on my other build.
LO will most likely be your best bet with what you have going.
good luck man, hope you break into the 15's
Thanks, Id be happy with a mid to low 15s, of course 14s would be better but im not holding my breath because I dont want to put that much into it.
lol you could run 13's with enough weight reduction hahahahaah
just busting ur balls, man. you know i love what ur doing.
Underdog Racing
z yaaaa wrote:lol you could run 13's with enough weight reduction hahahahaah
just busting ur balls, man. you know i love what ur doing.
Hahaha lmao. Truth be told though if I gave myself some weight reduction and some more seat time i probably could get a 15.9 as the car sits lol.
N I love what your doing too...Im definitely using your 2.3 rod mod in the other build.
I'd take it back to stock manifold if you could. I was running 15.7's with not too many mods when I ran those times. 15.6 is my times for the past 6 years but that was due to a very restrictive exhaust setup which is now gone so times should've improved since then.
Being an automatic car, you should be somewhat similar in times.
If anything, you could make sure that the intake manifold is perfectly port matched along with the exhaust side of things to make sure that all of the airflow is not going to waste through turbulence issues.
You'd be surprised how much of a difference a lip on the head or intake side can make so much turbulence on the intake path and/ or exhaust path.
I'll be making sure on my eventual build that this will be a certainty.
Go with the lo manifold and see what happens. Port match it though if you've got the time or if it isn't already done.
Knife edge your throttlebody plate to smooth out the airflow too and cut the thottlebody plate screws so they're flush to help maintain airflow velocity while minimizing turbulence into the intake runners.
It's the little things that count for that extra tenth lost in the 1320.
Good luck.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO! 
Misnblu wrote:I'd take it back to stock manifold if you could. I was running 15.7's with not too many mods when I ran those times. 15.6 is my times for the past 6 years but that was due to a very restrictive exhaust setup which is now gone so times should've improved since then.
Being an automatic car, you should be somewhat similar in times.
If anything, you could make sure that the intake manifold is perfectly port matched along with the exhaust side of things to make sure that all of the airflow is not going to waste through turbulence issues.
You'd be surprised how much of a difference a lip on the head or intake side can make so much turbulence on the intake path and/ or exhaust path.
I'll be making sure on my eventual build that this will be a certainty.
Go with the lo manifold and see what happens. Port match it though if you've got the time or if it isn't already done.
Knife edge your throttlebody plate to smooth out the airflow too and cut the thottlebody plate screws so they're flush to help maintain airflow velocity while minimizing turbulence into the intake runners.
It's the little things that count for that extra tenth lost in the 1320.
Good luck.
Yeah turbulence is a bad thing, I will definitely keep in mind your advice. I might try the stock manifold since I have 2 laying around. Im concerned about the bottom of the port in the head not having enough meat though as I did port match it to the other 2.3 manifold. As for the exhaust side my header and exhaust ports are both matched to the gasket.
Which 2.4 manifold is better? I have a 96-99 and 00-02. I remember one is supposedly better than the other but cant remember which is which.
The only difference between the 2 LD9 stock manifolds is on 99+ a small lip right under the TB. This can easily be taken out in 5 minutes. Mine is gone (not that I have it on the car anymore because of the charger.
FU Tuning
Screaming for Mercy!! wrote:The only difference between the 2 LD9 stock manifolds is on 99+ a small lip right under the TB. This can easily be taken out in 5 minutes. Mine is gone (not that I have it on the car anymore because of the charger.
I thought it was the EGR port on the 95-99 that was causing a restriction into the runners.
I know when I removed my EGR setup, I plugged up the hole pretty good but looking down as the air would flow into the runners, that plug or port is in the way of free flowing air.
Having gone to the junkyard and looking at the non EGR manifolds, it's nice and smooth in comparison so that's going to be one of my next mods to do once I head back out to the junkyard.
Screaming, I'll have to check that out now that you mention it. Being plastic it's pretty easy to do any kind of modifications to it.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!
james- john is correct, the newer mani's have a 'restriction' lip. the heads also have a tiny bit smaller exhaust ports.
Underdog Racing
z yaaaa wrote:james- john is correct, the newer mani's have a 'restriction' lip. the heads also have a tiny bit smaller exhaust ports.
Brad, I'll make sure to be on the lookout for it once I hit the junkyard.
I'll do whatever it takes to remove this lip for the best air flow. Thanks for the info.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!
I would use the stock intake manifold or the LO, but I think the LO will move the power-band higher than you want.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Im running the LO manifold and secret cams, seems to be a pretty good pair. Running a header with 1.5" primaries and full 2.5" exhaust.
Didnt seem to loose much bottom end over stock.
"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"
Im going to try the stock manifold because I already have one but I really think it wont work with my head, and if that fails then LO it is.
I run the LO and with the times I have are done with LO, I have done the HO and the stock, but with my cams they not as big as the ho but are bigger then secret cams, I only saw a benefit with the lo, but then again will move your powerband a little higher as was mentioned, and yes those tiny mods to the TB do help a bit, and weight reduction is nice, shame your an auto though
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen
Yeah I wish I bought a stick but im just making the best out of what I already have lol. I will probably end up having to go with the LO. I might try the throttle body mods.
Just make sure that you don't tamper with the diameter of the throttle body plate and only the lip if that makes any sense.
It's time consuming but a nice mod when it's done and a bit old school as well.
Good luck man.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!
Thanks and I love the old school stuff lol
