Thread: Comp Cam 280 XFI information needed?

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The Combo:
-383
-10.5 compression
-280 XFI hyd. roller
-AFR 180cc heads
-Pro Magnum 1.52s
-Holley Stealthram MPFI system(non-ported but deburred and polished)
-700R4
-3.73s
-Long tube 1 5/8" headers
-Intermediate dual 3" mandrel bend pipe
-Custom Corsa 3" exhaust
I'll get a 3000 or 3200 stall converter to best suit my needs.

This is my daily driver for another year so street manners has to be good and of course, must have performance...I will be tuning this personally from the moment it goes in but wanted some information about the camshafts characteristics before I buy it.
-Comp 280XFI(230/236 with .550 lift w/ 1.52 rockers and 113 lsa)

What I need to know is:
1) How is the idle?
2) Will it pull enough vacuum at 750rpms to run the ABS brakes?

This is for my 1990 Chevy C1500 2wd truck by the way.....I already have this combo in it for reference.
Here is the old combo:
-383
-9.5 compression
-218/224 flat tappet
-AFR 180cc heads
-Pro Magnum 1.52 rollers
-Holley StealthRam induction(stock)
-700R4
-3.73s
-Long tube 1 5/8" headers
-Intermediate dual 3" mandrel bend pipe
-Custom Corsa 3" exhaust

Originally Posted by sstruck383

The Combo:
-383
-10.5 compression
-280 XFI hyd. roller
-AFR 180cc heads
-Pro Magnum 1.52s
-Holley Stealthram MPFI system(non-ported but deburred and polished)
-700R4
-3.73s
-Long tube 1 5/8" headers
-Intermediate dual 3" mandrel bend pipe
-Custom Corsa 3" exhaust
I'll get a 3000 or 3200 stall converter to best suit my needs.

This is my daily driver for another year so street manners has to be good and of course, must have performance...I will be tuning this personally from the moment it goes in but wanted some information about the camshafts characteristics before I buy it.
-Comp 280XFI(230/236 with .550 lift w/ 1.52 rockers and 113 lsa)

What I need to know is:
1) How is the idle?
2) Will it pull enough vacuum at 750rpms to run the ABS brakes?

This is for my 1990 Chevy C1500 2wd truck by the way.....I already have this combo in it for reference.
Here is the old combo:
-383
-9.5 compression
-218/224 flat tappet
-AFR 180cc heads
-Pro Magnum 1.52 rollers
-Holley StealthRam induction(stock)
-700R4
-3.73s
-Long tube 1 5/8" headers
-Intermediate dual 3" mandrel bend pipe
-Custom Corsa 3" exhaust

I don't think it will even idle at 750 rpm's.
You don't need a 3,000 to 3,200 stall.
I would think 2,500 to 2,800 would work well.

Originally Posted by erik erikson

I don't think it will even idle at 750 rpm's.
You don't need a 3,000 to 3,200 stall.
I would think 2,500 to 2,800 would work well.

Yea, it will idle there after tuning...a few people on the thirdgen.org forums have it and said its not a problem. But, if the 4.8L boys and 5.3L GEN III engine trucks are running 226/226 cams in there trucks are 700rpms, I couldn't see why a 6.2L with a 230/236 with less valve lift would be any harder. 2500 to 2800 would work but the StealthRam is a tunnel ram design and 3000 would be more efficient for my powerband. Yank sells some nice 3000 stalls that acts like a 3400 and drives like stock so I can't complain there.

Originally Posted by sstruck383

Yea, it will idle there after tuning...a few people on the thirdgen.org forums have it and said its not a problem. But, if the 4.8L boys and 5.3L GEN III engine trucks are running 226/226 cams in there trucks are 700rpms, I couldn't see why a 6.2L with a 230/236 with less valve lift would be any harder. 2500 to 2800 would work but the StealthRam is a tunnel ram design and 3000 would be more efficient for my powerband. Yank sells some nice 3000 stalls that acts like a 3400 and drives like stock so I can't complain there.

So if you already think it idles at 750 rpm's why even make a post??
Choosing a converter has very little to do with intake design.
So are you saying that if your runner length is a little longer you need to run a higher stall speed??
You talk about street manners but then you talk about a "nice 3000 stall that acts like a 3400 and drives like stock".
A 3,400 stall is not going to have nice "street manners" and it will not drive like it is stock,it is going to get hot and you will need to run a very large tranny cooler if this is going to be a "daily driver".
If I was you I would do a little more research.

Originally Posted by erik erikson

So if you already think it idles at 750 rpm's why even make a post??
Choosing a converter has very little to do with intake design.
So are you saying that if your runner length is a little longer you need to run a higher stall speed??
You talk about street manners but then you talk about a "nice 3000 stall that acts like a 3400 and drives like stock".
A 3,400 stall is not going to have nice "street manners" and it will not drive like it is stock,it is going to get hot and you will need to run a very large tranny cooler if this is going to be a "daily driver".
If I was you I would do a little more research.

Well, I didn't ask where it would idle but I asked about idle characteristics....mainly vacuum readings b/c of the power brakes and would the cam act/be streetable. Couple of thirdgen.org members run the 230/236 on a 110 lsa and this one has a 113 lsa(which should be better for idle and vacuum), I didn't want to have to have a vacuum assist on the brake system. Obviously, you don't think it would be a good idea. Thanks for your comment but do you have any hard data on the cam to support the answer. If so, share b/c that's what I am wondering about. Yea, I know choosing a converter has nothing to do with the intake but the combination of parts in the engine and if I do this setup a 2500-2800 would work(not saying it wouldn't) but all the converter places have recommended a 3000 or 3200 stall with a 2.3 STR and the setup would be a tight converter so the street manners are good. And by places, I am talking about Yank, Edge, and Vig.

Henry Rifle-Lots of people with the Yank converters say it acts like a stock converter with a 3000 or 3200 rated stall. However, they say it really flashes to (depending on power, application etc but since I have been talking to trucks guys about it and they are making about the same amount of hp but less torque than me), they all flash to 3400. And also have good street manners. I have a 16" x 9" aux. tranny cooler on it already along with the radiator so should have plenty of cooling for it.

The 700R4 has a lockup on the 4th gear and an auto came with the truck so, that's what will stay. Stick is funnier to drive no doubt, but the auto will stay.

The Stealthram is a tunnel ram design by Holley to replace the TPI system from the 85-92 Camaros and 85-88 Corvettes. The power band on my last setup was 2000 rpms to 5300 rpms. I dynoed it when it wasn't tuned and had a nice flat torque curve from 3000 to 4000 rpms. So, with the bigger came, I was looking into 3500 to 4700 torque curve. The Stealthram is very streetable.

So, just need some information about the cam. Dyno Desktop shows this combination making 512 hp @ 5800 rpms and 526 ft lbs @ 4300 rpms. By using the 800 rpm ruler before peak toruqe....that would be 3500 rpm stall but since the torque curve is flat with the induction system, a 3000 would be fine.

You are trying to get in the house thru the basement door ......use the front door. First off forget vaccume readings....a vac boost can is like 50 bucks and you can use any cam you want,Second forget idle quality ,you threw that out the window when you went for 500 hp.
Match all the components together for your goal and let the idle and vaccume find where they want to be...not where you would like them to be.The idle and vaccume your motor will see is already set by the cam you chose.
Set a goal and let the goal tell you what parts to buy for the engine.Then match those parts together and let the motor be all it can be.Do not pick a 500 hp winner and then cripple it with trying to get the vaccume up or idle down.
Sounds like you want a race car in a truck that runs like a stocker.Your goals either need to be idle and vac quality or peak hp.Trying to get tooo many things from one engine will only insure it does none of them well...

The only way to get what you are telling us you want is fuel injected and supercharged.Idles well ,gets good gas mileage,and has a good vac signal and makes power.A 500 hp carb deal in 383 ci is not going to be friendly to daily driving ....unless 1000 rpm idle and low vaccume and trans coolers everywhere are acceptable and you had better keep lots of tuning tools with ya if the weather changes too much on you while your out!!!
Now if you were doing 500 hp with 550 cubic inches then this would be a different story.

Originally Posted by sstruck383

Well, I didn't ask where it would idle but I asked about idle characteristics....mainly vacuum readings b/c of the power brakes and would the cam act/be streetable. Couple of thirdgen.org members run the 230/236 on a 110 lsa and this one has a 113 lsa(which should be better for idle and vacuum), I didn't want to have to have a vacuum assist on the brake system. Obviously, you don't think it would be a good idea. Thanks for your comment but do you have any hard data on the cam to support the answer. If so, share b/c that's what I am wondering about. Yea, I know choosing a converter has nothing to do with the intake but the combination of parts in the engine and if I do this setup a 2500-2800 would work(not saying it wouldn't) but all the converter places have recommended a 3000 or 3200 stall with a 2.3 STR and the setup would be a tight converter so the street manners are good. And by places, I am talking about Yank, Edge, and Vig.

Henry Rifle-Lots of people with the Yank converters say it acts like a stock converter with a 3000 or 3200 rated stall. However, they say it really flashes to (depending on power, application etc but since I have been talking to trucks guys about it and they are making about the same amount of hp but less torque than me), they all flash to 3400. And also have good street manners. I have a 16" x 9" aux. tranny cooler on it already along with the radiator so should have plenty of cooling for it.

The 700R4 has a lockup on the 4th gear and an auto came with the truck so, that's what will stay. Stick is funnier to drive no doubt, but the auto will stay.

The Stealthram is a tunnel ram design by Holley to replace the TPI system from the 85-92 Camaros and 85-88 Corvettes. The power band on my last setup was 2000 rpms to 5300 rpms. I dynoed it when it wasn't tuned and had a nice flat torque curve from 3000 to 4000 rpms. So, with the bigger came, I was looking into 3500 to 4700 torque curve. The Stealthram is very streetable.

So, just need some information about the cam. Dyno Desktop shows this combination making 512 hp @ 5800 rpms and 526 ft lbs @ 4300 rpms. By using the 800 rpm ruler before peak toruqe....that would be 3500 rpm stall but since the torque curve is flat with the induction system, a 3000 would be fine.

Hard data??
If you count the fact that I build five engines a week and CNC port about three sets of heads a week and spend about a day and half in the dyno room,Wednesday night at the 1/2 mile dirt track,Friday night at another 1/2 mile dirt track,Saturday morning at the drag-strip,Saturday night at 1/3 mile dirt track.
I started building engine in 1983 and by 1990 I was building engines for a living.
You have to be the only person that thinks runner length dictates stall speed.
If you know so damn much why come on here and ask questions???

Originally Posted by sstruck383

So, just need some information about the cam. Dyno Desktop shows this combination making 512 hp @ 5800 rpms and 526 ft lbs @ 4300 rpms. By using the 800 rpm ruler before peak toruqe....that would be 3500 rpm stall but since the torque curve is flat with the induction system, a 3000 would be fine.

I would have to say that that is one very optimistic virtual dyno reading..... Or did I miss the supercharger or nitrous someplace?

Yup, the higher the stall the more heat it generates. Think I'll stick to manual transmissions and pulling the handle. Having 4, 5, or 6 gears really is nice when it comes to staying in the peak torque or horspower of the engine. IMO an automatic on the street forces a lot of comprimises in the engine build....

Hmmmm. A 3000 stall and a tunnel ram with street manners? A 3000 stall converter acts like a 3400 and drives like stock? Man, I want what some of those folks are drinking.

Jack
- I'd put a gear drive on it also . . .

I cheat on cams. I have my favorite Tech Rep at Comp Cams. I just give him all the data and have one built. I'm mostly a chassis and suspension guy.

Ah ok. I just sent Comp cams a request along with a few Custom camshaft people to see what they say but most of them don't give out the specs until its bought. Maybe I can get Erik back in here and see what he thinks would be better.

The biggest thing is the trucks weight.
Keep in mind this is a 5,000 lbs. truck not a 3,000 lbs. street car.
I would cut some of the duration out of the cam to try and move the powerband down a little bit.
I would look more at cams that are in the 220 area at .050 area.
If you like Comp. then look at cam number 12-423-8 this is the largest cam I would ever run in your truck.
Next your heads are a little on the large size for what you are doing.
They are not bad, but again you are working with a truck.
Your combo. would be dead on if you had it in the 3,000 lbs. street car.
In fact I have the same cam on my bench but I had it cut on a small base circle to clear everything in a 383 I am building for a customer.
If you do want to use the larger cam you picked out with your heads, with the 3,000 stall then I would say go to a 4.10 gear to try and help the truck to move off the line.

Originally Posted by erik erikson

The biggest thing is the trucks weight.
Keep in mind this is a 5,000 lbs. truck not a 3,000 lbs. street car.
I would cut some of the duration out of the cam to try and move the powerband down a little bit.
I would look more at cams that are in the 220 area at .050 area.
If you like Comp. then look at cam number 12-423-8 this is the largest cam I would ever run in your truck.
Next your heads are a little on the large size for what you are doing.
They are not bad, but again you are working with a truck.
Your combo. would be dead on if you had it in the 3,000 lbs. street car.
In fact I have the same cam on my bench but I had it cut on a small base circle to clear everything in a 383 I am building for a customer.
If you do want to use the larger cam you picked out with your heads, with the 3,000 stall then I would say go to a 4.10 gear to try and help the truck to move off the line.

Thanks for the reply Erik, the truck weighs 4100 lbs with me in it. Had it weighed. Does this effect your suggestion now?

Originally Posted by sstruck383

Thanks for the reply Erik, the truck weighs 4100 lbs with me in it. Had it weighed. Does this effect your suggestion now?

I would still try and look at cams that are no more than 220 at .050 with your weight and gear ratio.