Best intake for slightly worked GT40P's?

jaymac

New Member
Feb 18, 2004
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Northern Mass
As you can see in my sig, I have an Explorer intake w/ P's that have 55 cc chambers, and slight porting and polishing in the ports and bowls.
searched, but ony found threads relevant to stock heads or blown apps.
So, what would be the best choice for my P's?
TFS Street Heat?
Performer?
Systemax?
Whaddya think?
 
I'd go with the Performer 5.0 over the TFS intake. Or I'd send the Explorer lower to TMOSS for porting if you don't want to spend $499.99 or so. Systemaxx is a little too much intake for a near stock 5.0. Just my opinion.
 
No blower, staying N/A. Tmoss comented to me about porting the Explorer lower a few times, something about it not being necessary/worth it.
I don't know how much the P's flow after being worked on, but I'm running a 13.6 @ 98, and can't break 98. I was running 98 when I was rnning a 14.1.
The car has the torque, just not the HP at the top end. I'm just wondering if stepping up the intake will help...
 
jaymac said:
No blower, staying N/A. Tmoss comented to me about porting the Explorer lower a few times, something about it not being necessary/worth it.
I don't know how much the P's flow after being worked on, but I'm running a 13.6 @ 98, and can't break 98. I was running 98 when I was rnning a 14.1.
The car has the torque, just not the HP at the top end. I'm just wondering if stepping up the intake will help...

Did you ask Tmoss to suggest an intake...maybe he'll chime in...

I'd say Performer 5.0...
 
I think the explorer flows close to 200 cfm and the gt40(p)s flow close to 200. Remember - that is close to max valve lift. If you are running the stock cam, you ain't gettin the max cfm out of those heads. They like to flow max about .500. Stock cam is only .444 - with 1.7's about .474. I would drop a set of 1.7s rockers in it. That should help in my opinion....
 
If you don't know what the heads flow now, it's kind of a guess - but you can use a Explorer or Performer and be real close. If the heads flow more than ~225cfm, it's probably worth porting the Explorer lower or moving to a Performer - whichever is cheaper.
 
Are all Explorer lowers equal on the ports? My '99 is way smaller than the intake port on the heads. I have seen a cobra lower and it seems alot bigger. Would it be ok to just gasket match the ports?

I have an itchy die grinder trigger finger :D
 
:D typhoon intakes are cheap and should flow about the same, i see em for 200$ all the time on the corral classifieds, possibly a bit too big, but good if you go for nitrous or a blower later, maybe tmoss can chime in, hes the intake jedi!
 
tmoss said:
If you don't know what the heads flow now, it's kind of a guess - but you can use a Explorer or Performer and be real close. If the heads flow more than ~225cfm, it's probably worth porting the Explorer lower or moving to a Performer - whichever is cheaper.
:scratch: uhh... he already did...
 
jaymac said:
:scratch: uhh... he already did...

You used an Explorer, but have no idea what the heads flow, so it's hard to tell if porting will help that much. If the power is laying down before ~5,200 rpm, then porting will help the upper end as it will aid in filling the cylinders better at the lift he has (edit) by reducing the flow restriction built into the lower's design.
 
Well, with the stock tach, and no dyno tune as of yet, it's hard to gauge when the power curve stops. My stock tach apparently reads too high at the big end, as it reads far over 6 grand. I've been told this "has to be" innacurate.
I can only guess that w/ an inability to break 99 mph, even @ 13.6, there is some suffocation at the top end of the trip...
 
Hmmm - ask yourself how many miles are on the chain. Maybe it has a lot of slack in it if it is old - mine had WAY too much when I put my fresh chain on. Then I took the valve events and lift off my stock cam and got professional advice on how to install the cam - turned out to be 4° advanced, not what most guys would do with a stock cam - but the results have been very satisfying to me.