Edelbrock RPM II on stock long block?...I need more info from you guys

[badstang123]

I've been searching info on intakes a lot lately. I know of the Edelbrock's the Performer is the best intake for a stock longblock. I also know that for a future combo that I'm looking into (331 or 347 w/ AFR 185's) the RPM II would be best of the Edelbrock's (While still being emissions legal). I just wanted to let you guys know that I did search a lot and I understand the basic idea of things.

Now to my questions. I notice a lot of people saying that with the RPM II that you will lose bottom end on the stock longblock. I'm wondering what this is in relation to. Will I have less bottom end than with the stock intake on there? Or will it just be a little less than with the Performer?

Any suggestions and input would be greatly appreciated. Just keep in mind that this will be a mostly street driven car for the time being and once the motor is swapped. It will see occasional track time and mostly just for fun and not actual competitions where every tenth counts. I'm really open to either of these intakes but I want to buy the right one the first time with the future in mind (Porting the Performer is also an option once I switch motors if that would be the way to go too). Thanks.
- Justin

 

[badstang123]

Some info on the car would probably help so here it goes...Stock longblock, Mac cold air intake, BBK shorty headers, Mac Pro-chamber w/o cats, Mac cat-back, 3.73's, March pulley's, and I have a 70mm Edelbrock throttle body and the Edelbrock adapter for the intake sitting in my closet for once I get the intake. Thanks again.
- Justin

 

[ProKiller]

i'm not the biggest fan of doing things twice. i'd just go straight with the RPM 2 if you plan on doing the stroker in the somewhat near future. but unless you have already started saving and have a plan to get the new block in there i would get a used performer or performer RPM and run that until you get the block.

 

[Black95GTS]

Some food for thought is that the holley systemax intake lines up almost perfectly with AFR 185s. Might want to go that route if you're running an aftermarket hood. The stock hood won't clear it.

How do you know that the Edelbrock performer is the best?

One thing you could think about is buying a trick flow street heat, then upgrading to a track heat upper when you get the better heads.

Adam

 

[Killercanary]

Or get the performer now and buy a RPM or typhoon upper for it down the road when you get the stroker and such.

The problem with running something like a holley or an RPMII on a stock shortblock is that the intake is made to flow a lot of air. Their large port size and short runner length aids in high RPM's when massive amounts of air flow are needed. The problem is that these two characteristics also lead to a reducing in air flow velocity and cylinder filling at low rpms. This is the reason that you lose low end power and torque. The problem with using these on a stock long block si that the stock cam and heads will be done by the time these intakes get into their sweet spot and start to shine, so you might end up with a car that is lazy down low and is done up top right as these intakes would really start to make sizeable gains.

 

[Black95GTS]

Or get the performer now and buy a RPM or typhoon upper for it down the road when you get the stroker and such.

The problem with running something like a holley or an RPMII on a stock shortblock is that the intake is made to flow a lot of air. Their large port size and short runner length aids in high RPM's when massive amounts of air flow are needed. The problem is that these two characteristics also lead to a reducing in air flow velocity and cylinder filling at low rpms. This is the reason that you lose low end power and torque. The problem with using these on a stock long block si that the stock cam and heads will be done by the time these intakes get into their sweet spot and start to shine, so you might end up with a car that is lazy down low and is done up top right as these intakes would really start to make sizeable gains.

He could retard the stock cam while he saves for the rest of the combo. I did it in my engine, stock heads, stock cam, street heat. With my 4.10s I'm sure I could run a Holley without too much fuss.

For that matter, are AFR 185s emissions legal???

Adam

 

[Therian]

For that matter, are AFR 185s emissions legal???

Adam

As long as you get them with the EGR hole, then yes

 

[5spd GT]

Or get the performer now and buy a RPM or typhoon upper for it down the road when you get the stroker and such.

The problem with running something like a holley or an RPMII on a stock shortblock is that the intake is made to flow a lot of air. Their large port size and short runner length aids in high RPM's when massive amounts of air flow are needed. The problem is that these two characteristics also lead to a reducing in air flow velocity and cylinder filling at low rpms. This is the reason that you lose low end power and torque. The problem with using these on a stock long block si that the stock cam and heads will be done by the time these intakes get into their sweet spot and start to shine, so you might end up with a car that is lazy down low and is done up top right as these intakes would really start to make sizeable gains.

This would be my advice as well...

What was said about the Systemax is correct, it does match up a bit better than the RPM II to the aftermarket head like AFR 185's.

But again, I would take the advice in quotes...

 

[badstang123]

How do you know that the Edelbrock performer is the best?

I didn't say it was the best...I meant of the different Edelbrock manifolds those two fit into my needs for the two different motors best. I don't necessarily think that Edelbrock's are the best but for some reason, I'm partial to Edelbrock in my head and that is why i've headed that direction. Nothing against other intakes, and some might even be better I just like Edelbrock.

I have also read what a few of you stated about the Holley being great for the 185's. From what I saw though it looked as if it was even more intake than the RPM II and I figured there would be no way to run that on my motor now. That's the only reason I ruled that out.


Here's another idea: What do you guys think of the Performer and then having it ported by Tmoss when I'm swapping motors? With the porting will it match the numbers the RPM II or Holley Systemax could do? Thanks.
- Justin

 

[Black95GTS]

I didn't say it was the best...I meant of the different Edelbrock manifolds those two fit into my needs for the two different motors best. I don't necessarily think that Edelbrock's are the best but for some reason, I'm partial to Edelbrock in my head and that is why i've headed that direction. Nothing against other intakes, and some might even be better I just like Edelbrock.

I have also read what a few of you stated about the Holley being great for the 185's. From what I saw though it looked as if it was even more intake than the RPM II and I figured there would be no way to run that on my motor now. That's the only reason I ruled that out.


Here's another idea: What do you guys think of the Performer and then having it ported by Tmoss when I'm swapping motors? With the porting will it match the numbers the RPM II or Holley Systemax could do? Thanks.
- Justin

If your heart is set on the performer, then I would follow both KC's advice and your own. I'd get the performer, and when you're ready, have TMOSS port the lower to match the 185s while simultaneously switching to an RPM/Typhoon upper. Sort of a bastard child of an intake but I think it would do the trick. Has anyone ever tried this before?

Adam

 

[final5-0]

I think is is very wise to think ahead
and
You seem to have a long term goal in mind

If you were to do the same kind of thing for headers
then
I'd guess you would debate over doing 1 5/8 LT''s for now
and
Maybe switch out to 1 3/4 size later

I'd just do the RPMII now and do other things to prop up the
low end like LT's, Pulleys, 373's/410's, etc.

That was my game plan
but
I had a custom cam that helped obtain that goal

You could find a good bit of low and mid range
With spark/fuel table optimization
but
Thats gonna be kinda spendy

Grady

 

[badstang123]

I think is is very wise to think ahead
and
You seem to have a long term goal in mind

If you were to do the same kind of thing for headers
then
I'd guess you would debate over doing 1 5/8 LT''s for now
and
Maybe switch out to 1 3/4 size later

I'd just do the RPMII now and do other things to prop up the
low end like LT's, Pulleys, 373's/410's, etc.

That was my game plan
but
I had a custom cam that helped obtain that goal

You could find a good bit of low and mid range
With spark/fuel table optimization
but
Thats gonna be kinda spendy

Grady

I'm thinking along the same lines as you BUT...I got the shorty headers because I have to deal with the Smog Nazi's here in California. I actually listed what I have on the car so far in my second post.

I also have the MM strut tower brace to clear whatever intake and a 3.5" Cobra R hood so clearance shouldn't be an issue at all.

If your heart is set on the performer, then I would follow both KC's advice and your own. I'd get the performer, and when you're ready, have TMOSS port the lower to match the 185s while simultaneously switching to an RPM/Typhoon upper. Sort of a bastard child of an intake but I think it would do the trick. Has anyone ever tried this before?

Adam

If I go that route how hard is it going to be to get just an upper of an RPM. They don't make that intake anymore do they?

I can tell your not the biggest fan of Edelbrock so if it were your car in my situation what would you get? I'm kind of curious. I'm not dead set on anything yet. I'm leaning a direction, but want to get as much info as possible so I don't regret my decision later. Thanks.
- Justin

 

[WhiteDevil]

i'm not the biggest fan of doing things twice. i'd just go straight with the RPM 2 if you plan on doing the stroker in the somewhat near future. but unless you have already started saving and have a plan to get the new block in there i would get a used performer or performer RPM and run that until you get the block.

Yeah looking back i wish i would have just got the RPM II the first time. Especially if you have bigger plans in the future.

 

[Black95GTS]

I'm thinking along the same lines as you BUT...I got the shorty headers because I have to deal with the Smog Nazi's here in California. I actually listed what I have on the car so far in my second post.

I also have the MM strut tower brace to clear whatever intake and a 3.5" Cobra R hood so clearance shouldn't be an issue at all.



If I go that route how hard is it going to be to get just an upper of an RPM. They don't make that intake anymore do they?

I can tell your not the biggest fan of Edelbrock so if it were your car in my situation what would you get? I'm kind of curious. I'm not dead set on anything yet. I'm leaning a direction, but want to get as much info as possible so I don't regret my decision later. Thanks.
- Justin

Honestly, if I knew I was going to go 347, I would save up and get a set of Vic Jr heads, Vic 5.0 intake, and a custom cam all in one shot. That would make well over 400 HP and 400 torque in a N/A 347. Notice that those are all Edelbrock parts. I'm not against Edelbrock, I was just wondering if you knew something I didn't about the performer. I won't argue that there are a lot of fast edelbrock cars. Plus I LOVE the fact that all their parts are made in the USA.
90mm LMAF
90mm race TB
42 pound injectors
SCT Tune
4.30 rear end
T-56
Auburn Differential
33 Spline Axles
Full Length Subframes

IMO, this is the IDEAL N/A stock block street/strip combo. Shift point around 6500 RPMS. I'd send the lower out to get port patched to the Vic Jrs. This car will scream and on slicks and skinny's will put the car into the 10s. The key to this would be tuning, which I admit will be a bear. But that's why Don at LaSota makes the big bucks!

Adam

 

[badstang123]

Honestly, if I knew I was going to go 347, I would save up and get a set of Vic Jr heads, Vic 5.0 intake, and a custom cam all in one shot. That would make well over 400 HP and 400 torque in a N/A 347. Notice that those are all Edelbrock parts. I'm not against Edelbrock, I was just wondering if you knew something I didn't about the performer. I won't argue that there are a lot of fast edelbrock cars. Plus I LOVE the fact that all their parts are made in the USA.
90mm LMAF
90mm race TB
42 pound injectors
SCT Tune
4.30 rear end
T-56
Auburn Differential
33 Spline Axles
Full Length Subframes

IMO, this is the IDEAL N/A stock block street/strip combo. Shift point around 6500 RPMS. I'd send the lower out to get port patched to the Vic Jrs. This car will scream and on slicks and skinny's will put the car into the 10s. The key to this would be tuning, which I admit will be a bear. But that's why Don at LaSota makes the big bucks!

Adam

I agree that it doesn't get much better than that. Unfortunately I would run into a whole list of emissions issues in California. But if we're still talking intakes the Victor Jr. isn't legal...only the Performer and RPM II are.

And that kind of answers your other question or thought. It's not that I know something about the Performer you do not (In fact I'm sure I know less) it's just like I said, it and the RPM II have a carb number.
- Justin

P.S. - Now that you mention it, I think it might be that made in the USA thing that draws me to Edelbrock. It's getting far more rare on all types of products in this country.