950 proform HOLY CRAP what a diff!!

[firefighter3931]

Man those are nice!!!! I can see those mounted to a Stage V manifold on top of a certain 477 cube Hemi! Is the overall length the same as a regular Holley? I wonder if they would fit?

That carb won't work on a Stage V intake 

Doug, i think you should keep the inline dual quad setup on there...at least until we line em up 



Ron

[Hemidoug]

Man those are nice!!!! I can see those mounted to a Stage V manifold on top of a certain 477 cube Hemi! Is the overall length the same as a regular Holley? I wonder if they would fit?

That carb won't work on a Stage V intake 

Doug, i think you should keep the inline dual quad setup on there...at least until we line em up 



Ron

Well, if not the Stage V...I know they will work on the crossram....

How about this way?

[Charger-Bodie]

Now why would you want to put a throttle stop on it and keep it from opening up fully ? Must be a Chevy thing

Ron

Its to give the Cebbies a chance  

Here it is installed!! Ive adjusted it so it just barely touches when WFO.

Btw Ron, they said in the manual that the reason they recomend the stop is cause over time the linkage can wear and stick WFO without the stop in place .......I figured it be better safe then up a tree like a dummy 

[firefighter3931]

Here it is installed!! Ive adjusted it so it just barely touches when WFO.

Btw Ron, they said in the manual that the reason they recomend the stop is cause over time the linkage can wear and stick WFO without the stop in place .......I figured it be better safe then up a tree like a dummy 

Brian, assuming the linkage sticks/binds (or the return spring breaks) that stop won't do a thing....the throttle will still be wide open. 

Throttle stops are used in drag racing applications to slow cars down by limiting throttle travel and that's what they are designed to do. A throttle stop will not return the blades to a closed position. 


Ron


Ps. I noticed you only have a single return spring....do yourself a favor and use a double spring. 


http://store.summitracing.com/partdetail.asp?autofilter=1&part=LOK%2DSRK%2D4002&N=700+4294925239+4294839063+4294859612+115&autoview=sku

[firefighter3931]

Man those are nice!!!! I can see those mounted to a Stage V manifold on top of a certain 477 cube Hemi! Is the overall length the same as a regular Holley? I wonder if they would fit?

That carb won't work on a Stage V intake 

Doug, i think you should keep the inline dual quad setup on there...at least until we line em up 



Ron

Well, if not the Stage V...I know they will work on the crossram....

How about this way?

Hey...that's cheatin !  That Hemi crossram sure looks badazz....you got enough motor for that induction setup ? 


Ron

[Steve P.]

That's what I put on my daughters car when she started burning up tires...

[Hemidoug]

Hey...that's cheatin !  That Hemi crossram sure looks badazz....you got enough motor for that induction setup ? 


Ron

HEHEHEHE...YEA.......she's got enough....     May have to ditch those stock exhaust manifolds and find that hook first!

The question is....do you?.........

The stock manifolds are really holding that motor back right now....I think she has another 100 HP in her if I went to something more exotic.... the problem is that I will loose that stock look I've been trying to maintain....Then again...it's nothing a wrench and some time can't fix....

[Charger-Bodie]

Here it is installed!! Ive adjusted it so it just barely touches when WFO.

Btw Ron, they said in the manual that the reason they recomend the stop is cause over time the linkage can wear and stick WFO without the stop in place .......I figured it be better safe then up a tree like a dummy 

Brian, assuming the linkage sticks/binds (or the return spring breaks) that stop won't do a thing....the throttle will still be wide open. 

Throttle stops are used in drag racing applications to slow cars down by limiting throttle travel and that's what they are designed to do. A throttle stop will not return the blades to a closed position. 


Ron


Ps. I noticed you only have a single return spring....do yourself a favor and use a double spring. 


http://store.summitracing.com/partdetail.asp?autofilter=1&part=LOK%2DSRK%2D4002&N=700+4294925239+4294839063+4294859612+115&autoview=sku

according to the proform paper work they want it on there so that the cable isnt trying to still pull on the linkage after the butterflies are all the way open causing wear on the carbs linkage, inturn making it bind eventually. basically it hits the stop and the pressure is on the throttle cable insead of the linkage. do you smell what im steppin in?

[firefighter3931]

Hey...that's cheatin !  That Hemi crossram sure looks badazz....you got enough motor for that induction setup ? 


Ron

HEHEHEHE...YEA.......she's got enough....     May have to ditch those stock exhaust manifolds and find that hook first!

The question is....do you?.........

The stock manifolds are really holding that motor back right now....I think she has another 100 HP in her if I went to something more exotic.... the problem is that I will loose that stock look I've been trying to maintain....Then again...it's nothing a wrench and some time can't fix....

Doug....mine was quite happy with the single 4bbl....there might be a few extra HP with a dual quad setup but then you end up giving away some bottom end torque. Not worth it for me. 

I doubt that a set of headers are worth 100hp....those Hemi short tube "headers" work pretty good.  The FAST guys are making 750hp through those manifolds which is very impressive. Now on a big inch wedge....i could see 75hp with a header swap. 


Ron

[firefighter3931]

according to the proform paper work they want it on there so that the cable isnt trying to still pull on the linkage after the butterflies are all the way open causing wear on the carbs linkage, inturn making it bind eventually. basically it hits the stop and the pressure is on the throttle cable insead of the linkage. do you smell what im steppin in?

As long as the throttle cable is properly adjusted there should never be an issue with the linkage over-extending. I understand what they are trying to accomplish but to me it just seems like a bandaid solution to a minor problem....one that won't exist if everything is properly set up. 


Ron

[Steve P.]

I agree, but I can see their point. Tell me you never tried to push the go peddle through the floor.....   Seriously, there are many cables out there being used and not all of them are adjustable or are ever adjusted right. Then you have the manifolds that give you cable grief and guys are making their own brackets. I guess I can see their point. More of a Better safe than sorry. OR if the throttle plates and shafts wear prematurely they can say, (we told you to use our throttle stop). NO REPLACEMENT.

[Hemidoug]

I doubt that a set of headers are worth 100hp....those Hemi short tube "headers" work pretty good.   The FAST guys are making 750hp through those manifolds which is very impressive. Now on a big inch wedge....i could see 75hp with a header swap. 


Ron

I didn't mean just headers...I meant both intake and exhaust. The stock intake leaves a lot to be desired. It's well known that switching to a good quality 4bbl manifold will get you am increase in torque/HP. Those exhaust manifolds they are using in FAST are pretty gutted out with extrude honing. The problem with the stock intake is fuel distribution and fuel puddling. A switch to the Stage V manifold nets 50-60 HP...combined with a GOOD set of carbs and headers you can see that 100 HP isn't to far from the realm of possibilities....

[firefighter3931]

I doubt that a set of headers are worth 100hp....those Hemi short tube "headers" work pretty good.   The FAST guys are making 750hp through those manifolds which is very impressive. Now on a big inch wedge....i could see 75hp with a header swap. 


Ron

I didn't mean just headers...I meant both intake and exhaust. The stock intake leaves a lot to be desired. It's well known that switching to a good quality 4bbl manifold will get you am increase in torque/HP. Those exhaust manifolds they are using in FAST are pretty gutted out with extrude honing. The problem with the stock intake is fuel distribution and fuel puddling. A switch to the Stage V manifold nets 50-60 HP...combined with a GOOD set of carbs and headers you can see that 100 HP isn't to far from the realm of possibilities....

While i agree the stock dual plane will restrict some airflow on the top end...it will still produce better torque numbers down low. It just depends what you want....there are no free lunches so to speak. On a mostly street car i'm not sure i'd trade 50hp for 50 ftlbs. Now on a car that launches at 4500 and shifts at 6500-7000 the single plane makes sense.

On the headers ; going too big will also hurt the bottom end power. I know the TTI hemi headers are 2.25 primary tube diameter which is a little big for low rpm operation, inmo.

Going single plane with a set of headers will change the characteristics of that hemi...not necessarily for the better in a mostly street/limited strip application. 


Ron

[Dartbloke]

Talking of return springs, this is a nice set up also available in anodised colours, really go well with that trick looking Proform...

[Mick70RR]

It's been dry here today so I had the car out for an hour or so. The carb is working well with the exception of a slight off-idle stumble starting off on a very light throttle. If I give it a few more revs before I take off it's fine. If I mash the peddle from a steady cruise it responds instantly with no hesitation at all, the car just takes off like scalded cat.
The idle is good, 850rpm and 10 in of vacuum. All 4 idle screws are half a turn out, if I screw any one of them in a quarter turn the car wants to stall and if I screw any of them out a quarter turn the revs drop and it loses throttle response. When I tap either of the pump levers there is no change in rpm.
Ignition timing is 22* at idle, 37* all in at 2200rpm and I have the vacuum advance connected to ported vacuum and is limited to 10*. I checked and there's no ported vacuum at idle. I thought the vacuum advance may be causing the stumble and disconnected it but it was the same so I refitted it.
The slight stumble is no big deal but it would be nice to sort it out, any ideas?

[Animal]

Take the mixture screws out a hair Mick.

[Mick70RR]

Adam, that's what I thought so I tried it but it was just the same. I get the feeling this is a common problem that can be sorted out but there's no simple solution that works for everyone. Just wish the weather was better and I could get out and do more testing but it's rained again tonight so it don't look good for tomorrow.

[Animal]

1/4 turn is excessive when tuning , i would go 1/8 of a turn , sounds like it's too lean from idle to transition , had the same problem.

You might find the motor likes around 34/36 total , all in @ two thousand eight hundred rpm , seems to be coming in a little early.

[Mick70RR]

I only turned the primaries out another 1/8 turn, but you may be right on the ignition timing, I fitted some lighter springs a few days ago and it's all in buy 2200rpm now. I've been out in the car a couple of times before today, but the roads were wet, and don't recall having this problem, but I was just hooning around getting the car sideways at every opportunity. No sign of detonation though.

[Animal]

That stroker sounds fun.

May wanna bring those sec idle screws out a tad too.

[Mick70RR]

Been dry here today so I've been out all morning playing with the carb. First thing I did was fit some heavier springs in the dizzy and now it's all in by 2800rpm. This didn't make any difference but I'm leaving it like that.
Both primary and secondary throttles were open one turn of the screw, so I closed down the secs a half turn and opened up the primaries about a half turn. Now the primaries needed more fuel so I set the mixture screws a full turn out to get maximum vacuum, the sec mixture screws were still ok at half a turn out. This improved things but still not perfect so I gave the primary idle srews another half a turn out and the problem has completely gone away. No off idle stumble and the throttle feels so much better at low revs. I am starting to like this carb a lot.

[Animal]

Well done Mick , glad you got it sorted.

[firefighter3931]

Excellent work Mick...the Proform carbs have a nice fuel curve & you just have to find the right tune for your particular combination. 



Ron

[Duey]

Fitted the carb this afternoon. The weather here is cold, wet and foggy so I didn't take it out but it idles good and feels more responsive than the Edelbrock. Played around with the idle mixture screws and ended up with them all screwed only half a turn, 10 inches of vacuum. Can't wait for some dry weather so I can go out and play.

Mick, we're almost twins! (except I'm an 850...well, and it's not on the car right now.)

[/img]

Mick, Brian, what did you guys do for throttle linkages?  Brian, looks like you welded the old piece onto the PF's bellcrank?


p.s.  Ron, I'm back in country again and moving to Ottawa (well, during the week, fam still down in K-town).  I have to hang up my flying gear and start driving a desk! 

Cheers,
Duey

p.p.s.  Brad, bro...I'm in a new job and may actually have a better chance of coming to see you in the spring.  Hope all is well.

[Charger-Bodie]

Yes Duey , I welded an adapter to mine  it has a bolt at the bottm and a tack of weld at the top.