Manifold indecision

[stang4u2nv]

hey guys, its been a while since i have been on the forum and i have a question about my intake manifold choice....at the moment my 94 gt sports a set of edelbrock rpm 2 heads 1.90in 1.60 ex valves an Fcam, longtubes and 1.72 scorpion rockers. as for manifold i bought a long time ago a holley systemax intake and a 75mm throttle body with no elbow. the car runs good but i feel like i might be leaving some torque on the table. i think i went too big on the manifold because the intake runner on the manifold is bigger than those on the heads. at least looking at the gaskets and markings i'm seeing. the car i really only rev it to like 5700-5900 depending on the gear and it really hauls ass after 3500 or so. my question is would i gain more torque and horses by switching to an explorer intake manifold? because i can get those mad cheap around here and sell my systemax. any suggestions and or ideas? i'm also not running an elbow its just the throttle body bolted to the manifold. thanks in advance. :headbang:

 

[blackpony]

id say that with your combination, you could possibly be leaving some torque on the table... with such a mild application, a smaller runner intake could potentially help you out... i have a similar setup but smaller cam and maybe a little bigger head then you, and have a ported cobra and it has gobs of torque from about 2500-5500..... my .02

 

[LAFENATU]

GT40/Cobra/Explorer manifolds are torque monsters.

If your interested in selling the holley...PM me.

 

[stang4u2nv]

sure thing lafenatu...i'm seriously considering getting rid of this manifold...all this issue came up because i ran a fellow stanger and he has gt40 heads and intake with the same cam...i sold him all these parts and we rolled on second gear at about 3k and when we stepped on it i stayed with him for a split second and then started to pull away...obviously because of the hp numbers over him but i was surprised how much torque his engine made and his throttle response is also much better than mine. we even have the same gears...stock 3.08's. anyways thanks for your replies is anyone else thinking i should change mani's? do you guys think this gt40 manifold will choke my engine up top???? thanks

 

[5.0kid]

I would say it would be a good idea to change intakes if you want to. The only thing i can say about the swap, is that are you wanting to do anything more to the engine down the road? If so, you may want to keep ahold of that intake. if not, right now I think that the cobra/gt40 intake could really help your torque down low, and if you don't rev it too high, you won't notice much loss of power up to probably around 5200 or after...also, what kind of throttle body are you running? and did you do the fox swap, or are you just running an sn95 cable? cause that may cause you some throttle response to be off....

 

[stang4u2nv]

yes i'm still running the sn95 cable but i made a bracket that picks up the slack left over so the throttle is fine. i mean i just don't want to choke my little motor with the swap. (undecided)

 

[LAFENATU]

The power difference is negligable for what you have.

Torque is a different story...the GT40 gives you nasty torque. I love my tubular GT40.

 

[stang4u2nv]

like i said i'm not crazy about the power loss i know it won't be that much....but the torque i feel will be a good gain probably 15lbs or so after all 5.0's are all about torque....thats why i drive stang and not a supra which lack major torque. anyways should i sell my 75mm throttle body and get a 70mm unit? that would be my last question.... :icon_salut: how much can iget for this intake if i sell it? and i forgot to mention the intake has a 1" phenolic spacer from summitracing. let me in some ideas.

 

[LAFENATU]

The inlet on a GT40 is 70mm so 70mm would be best but you don't have to give it up. To be honest, for the setup you have a 75mm is really big, almost to big imo.

A used Holley and a spacer usually goes for around $400. If it is brand new but selling from private person they usually go for $450-475. My buddy just sold his with about 1000 miles on it for $450 shipped.

Here you go...perfect example.

http://forums.corral.net/forums/showthread.php?p=9355559

 

[Javi]

$400 shipped
http://forums.corral.net/forums/showthread.php?t=1160028&highlight=holley+systemax

$400 shipped
http://forums.corral.net/forums/showthread.php?t=1159120&highlight=holley+systemax


$400 shipped and polished:
http://forums.corral.net/forums/showthread.php?t=1151819&highlight=holley+systemax

$400 shipped:
http://forums.corral.net/forums/showpost.php?p=9057777&postcount=15

 

[stang4u2nv]

ok fellas i'll sell it for 475 shipped and it includes upper and lower, 1" phenolic spacer and extended bolts for upper manifold only i keep the lower bolts. this manifold is in near perfect condition. i would also like a trade if this is whats desired 300bucks for the manifold and items listed above and a cobra gt40, explorer or gt40 tubular unit, either one of these for my holley systemax unit. pm me for pics and info.

 

[stang4u2nv]

sorry "javi" i can't sell you the systemax for $350 shipped to your door. i'm a nice guy but not that nice.

 

[Javi]

sorry "javi" i can't sell you the systemax for $350 shipped to your door. i'm a nice guy but not that nice.

dont be nice, would you do $400? lol
jk man

 

[Paul]

A tubular GT40 is worth as much or more than your Systemax.

Changing manifolds is a waste of time and money. The Systemax II is a proven performer for HCI 5.0s. You already have one of the best (or the best) manifold on the market. The gains (or likely losses) in performance will likely be negligible. Is all the time and expense worth it to you for a 5% (predicted) increase in torque?

Paul.

 

[stang4u2nv]

oh hey Paul thanks for joining us. i really don't know if it'll be worth it i know the manifold i got is good i just thought i might keep the horses and add some torque since i'm getting rid of my turbo kit i didn't know if i needed this big manifold....anyways what is your input in this matter? should i or not sell the mani?

 

[Javi]

dont sell it.

 

[Paul]

Keep it. The Systemax II might be just a tad large, but not enough to warrant replacement.

Paul.

 

[stang4u2nv]

allright i guess it makes sense. they suggest it for blower and turbo cars which is what i was before but now i'm heading back to nitrous...thanks in advance.