Edelbrock RPM 2 intake... whoops???

[68converted]

I have been reading posts by tmoss and other intake pros, and I have to make a choice on intakes. I jumped the gun and bought the RPM2 intake. Now after reading a bunch, and I mean a bunch of posts, I think I made the wrong choice. Here are the stats: AFR 165 heads, 1.6 RR's, Xtreame Energy 270HE cam, 70 MM TB, 73 MM Mass Air, stock bottom end, with Hedman shorties, and 2 1/2" exhaust.

I think the better choice would be the Cobra or GT-40 intake. What do you think? I am getting close to starting up this project and don't want to fire it with an intake that is brand new if I am just going to switch it out.

 

[5spd GT]

I believe you could use a "smaller" intake to keep your useable powerband, more useable

A ported Performer would be fun. A ported GT-40 would be fun. A ported Cobra would be fun.

Good Luck.

 

[LiquidGT]

That intake is better suited for something like a 347.
Peformer, GT40/Cobra, one of the smaller TFS intakes would be good.

 

[68converted]

Yup, I am thinking the same thing. My question is this; if I do decide to go with the GT-40, why is it so important to port it? Wouldn't that just get me back to the same flow numbers of the RPM2?

 

[macx]

Porting the GT-40 (you can only port the lower cuz the upper isn't cast it's tubular)
will basically improve the dogleg in the front runners and the problems they cause with uneven distribution.

The big factor with the GT40 types is the mid range torque which is significantly
over the aftermarket intakes below low 5's rpm range, which is where you're gonna spend 95++% of your time on the street.

 

[68converted]

Porting the GT-40 (you can only port the lower cuz the upper isn't cast it's tubular)
will basically improve the dogleg in the front runners and the problems they cause with uneven distribution.

The big factor with the GT40 types is the mid range torque which is significantly
over the aftermarket intakes below low 5's rpm range, which is where you're gonna spend 95++% of your time on the street.

That is the exact reason for the switch idea. I will want way more torque down in the RPM range. I am pretty sure I want to make the switch, but now I have find someone who wants the RPM2...

 

[jhonda]

I went to the dyno recently and a intake makes a world of differance on sizing.
There was a 93lx mustang with basically the same modifications as me but still had the stock mass airflow sensor, and also had equal length bbk headers, coldair intake, and bbk intake manifold (one of the big ones that comes up on both sides). We made the same power till about 5500rpms and then he gained 13whp to about 6000rpms and 10wtq.......but I had about 8wtq on him in the bottom from about 2000-4000rpms and maybe 1-2hp.
We also had the same air fuel ratio and I had about 2degrees more timing than he did.

 

[5spd GT]

Is the RPM II brand new in box? You could just return it

Someone like Tom porting the intake will only help. The longer runner intake tunes in at a lower rpm. A little porting in the right areas, and you can also see some power up top.

 

[68converted]

Unfortunately the Intake is now installed (but never started/run). I know that I want to switch it out to the GT-40 intake, maybe one that is ported by a pro like Tom.

I saw the dyno numbers for the intakes he has done, and the lower range that his are producing the maximum power in is right where I want to be. I do have the AOD, so I would be cruising at about 2800 RPM that is really the bottom end of the power range for the RPM2. I really want idle-5500.

Note to self: Stupid ego, Stupid ego, Stupid ego, Stupid ego,

 

[Sonicaceman]

old post, if you check here is an intake tip

you have probably installed your new part and gone on with this a while ago but i was reading it and your last sentence said idle-5500, sounds familiar. the edelbrock performer which is about $495 is exactly in that range for a 302 and i had one on my car when it was a 302 and it worked very well, i heard a lot about the gt-40 so i switched out to that. this was about 4 years or so ago and since i have put a 347 stroker in the car. both intakes work great but the gt-40 has awesome midrange and even really good low range tq. through the power band up to about 5000 rpm. it's a trade off but now i realize with the 347 i should have upped the intake with my 347 to the rpm II that you originally had. hope it turned out good for ya.

 

[from6to8]

Unfortunately the Intake is now installed (but never started/run). I know that I want to switch it out to the GT-40 intake, maybe one that is ported by a pro like Tom.

I saw the dyno numbers for the intakes he has done, and the lower range that his are producing the maximum power in is right where I want to be. I do have the AOD, so I would be cruising at about 2800 RPM that is really the bottom end of the power range for the RPM2. I really want idle-5500.

Note to self: Stupid ego, Stupid ego, Stupid ego, Stupid ego,

So how'd the whole thing work out for ya? I have had my current combo since 04 and will post here with what I did today.

Today I reset the idle using just the stop screw. I turned the Idle bypass screw clockwise till it stopped and backed off the stop screw until it barely touched the base of the stop. I know the instructions say .10 on the feeler gauge then about 1 1/2 turns the opposite direction. I then unplugged the IAC and started the car, having my son play with throttle until I got back in front of car. I first tried turning the Idle bypass screw in increments to see it it helped keep the car running and it didnt. When I got to 2 full turns it still didnt keep car running so I had turned it back clockwise till it stopped/closed. I then had to turn the stop screw in tiny increments till the car would stay running, then I turned back in small increments back to get it to where it would just run,barely, with IAC unplugged. I then turned the car off leaving it switched on and checked the tps and it was at .98 so it was fine. I waited about 10 minutes then plugged back in IAC and went for a drive.

It seemed to make some difference with having the Idle bypass screw completely closed. Rpm's still seemed to move about the same between gears. It seems as if the rpm's since I have done all the up to date maintenance, it seems as the car tachs up fast but it just doesnt seem too torqy and mainly down low. NOw if I'm in say 2nd gear and have the rpm's about 2-3 the car is much much stronger. I guess that's just the powerband for that performer rpm 2 cause I think it power comes on about 2500-3k. I wonder if a new, up to date tune would add any power/torque down low. Remember I have a tune from 05 and was done with an autologic 2000 chip which no one does anymore? I guess an intake more suited for my combo would have been the best overall solution but I swear I would hate to take that intake off and put another on. I also called a few tuning places as well as edelbrock and trick flow and talked to the Techs. They all pretty much said with the performer 2 it should work well and not be an issue of being too big.

 

[mikestang63]

I believe you can buy the Performer upper itself and swap it for the II upper, and then sell the II upper, unless you have a really old version of the performer. The bolt pattern changed about 10 years ago.

 

[from6to8]

I believe you can buy the Performer upper itself and swap it for the II upper, and then sell the II upper, unless you have a really old version of the performer. The bolt pattern changed about 10 years ago.

Now that would be worth trying then. If I could find someone who has one and try theirs, that would be the better way to go vs buying one and getting stuck with it if I aint happy with the results. I would check some used options as I might not even be able to just buy the upper in the store????? I'm gona call edelbrock now to see if they are open today.

well they are closed today. One thing about buying used is making sure it would indeed bolt up to mines. I bought mines in 03 or 04

 

[mikestang63]

I've owned both the old style and new style Performer. I think the old style had 8 bolts and the new one has 6 for the upper to lower? It's been 10 years since I owned them so bear with me. As long as the Performer you buy isnt the old school with the removal inspection plate that is finned, you should be good to go. Check with Edelbrock anyway.

 

[from6to8]

I've owned both the old style and new style Performer. I think the old style had 8 bolts and the new one has 6 for the upper to lower? It's been 10 years since I owned them so bear with me. As long as the Performer you buy isnt the old school with the removal inspection plate that is finned, you should be good to go. Check with Edelbrock anyway.

yeah mine has 6 im pretty sure