I just got my car back today and drove it for the first time. It didn't feel very fast.This is probably due to the lack of gear and no posi,and a 2500 stall.Not to mention it is on headers at the moment. What is the stock gear ratio for a stock 10 bolt on a 69 camaro,it's the standard model. This is my combo:
350
trick flow heads
Scorpion 1.5 roller rockers
Performer RPM intake
Comp Cams 274XE
dynomax cerama coated headers

I had some people on here desktop dyno it and it made good #'s and good torque too. Comments,suggestions or insight would be greatly appreciated,thanks.

I am not sure what you mean by "it is on headers at the moment". Is this a fresh engine? If so, it will take a bit for it to loosen up, but most likely it just needs some fine tuning. Unless it has something like 2.56 gears...then it will always be sluggish until that it corrected. What initial/total timing are you running? How much cranking compression? Idle vacuum?

You're running a pretty big cam in there so you have to look at what your rear gears are and your tranny. If you are too high geared it will bog at low RPM's. Check the year of your car on the first page of this site. It has a link to the rear end numbers listed and the ratios.

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'68 Camaro Coupe
350, PG trans

I said the same thing when I first put my engine together. Everything is tight right now which takes away horsepower. I'll bet when you shut the engine off, it stops spinning instantly. After mine loosened up, it ran alot better. I would also imagine that you are still doing some tuning. After everything is in good tune, your engine will make better power too. Basically drive it around some more and play around with timing and carburetor tuning.

You would have to have some really high gears to bog it down. I had that cam and those heads in a 400 small block. It would pull out with a four speed and 2.73 gears easy. I had plenty of low end torque. I wouldn't think that you would have as much, but you still should have pretty good torque at lower RPM.

Also, just a warning. If you have the 1.25" springs on those heads, keep an eye on the spring dampeners. I broke three of them with that cam in about a year and 5,000 miles of driving.

I think my 10 bolt non posi rear end might have 2.73 in it.I'm running a TH-350 w/ a 2500 stall. The bottom end is already broken in,it is my old motor it only had maybe 3k miles though.So the cam/rockers/headers/and heads are new. I have moroso trick front springs and some CE 3 way adjustable shocks for the front and rear,maybe i'll get those on there with some subframes. I'm sure driving it on headers and getting hardly any back compression was killing low end torque. Hopefully I'll have the exhaust back on soon.Posi and gears probably would make a really big difference

That cam needs 3000+ stall and atleast some 3.55's when you use it with a 350. Otherwise, you've seen the results.

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79' Z28...

I drove a TC members 69 Camaro with a 468" BBC roller cam combo and a 4 speed. DD2k had it at about 560 HP and the engine was "put together right".

I could BARELY get the car to launch with lots of clutch slip after even a lot of tuning and the thing was still just plain a dog. Well I noticed that idling in 1st we were running like 25 MPH so we checked the rear end gear - 2.56 gears http://www.camaros.net/forum/eek.gif

He later switched to a 4.11 and oh my God that thing came alive! Gears make a huge difference.

<BLOCKQUOTE>quote:</font><HR>... I'm sure driving it on headers and getting hardly any back compression was killing low end torque. Hopefully I'll have the exhaust back on soon.Posi and gears probably would make a really big difference[/B]<HR></BLOCKQUOTE>

I'm interested in understanding how 'back compression' develops low end torque. If I put a throttle plate in my exhaust system, say one in each collector, could I close it off at low rpm's and get a lot more torque?
Or would I be better off using a set of headers of a size and length that develop sufficient velocity at low rpm's to effectively scavenge the cylinders and increase the VE?

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1967 Nova coupe daily driver
406, 10:1, 224° cam, Q-jet, 700R4, 3465# w/driver
11.75 @ 117 thru the mufflers
18 mpg on the road

maybe back compression was the incorrect term,my bad if it was.But wouldn't running full exhaust with mufflers have a little more low end then if I just was running headers?

The words you were looking for is "back pressure" and yes it does make a difference on low end torque. I doubt that is why your car feels slow. Check your rear gears and tuning.

onovakind, There are several exhaust systems on motorcyles that do exactly what you were mentioning. I had one (Yamaha FZR) it was called an EXUP system. The new CBR 954 also has a similar system. This is to give you the best of both worlds. Low end torque (the valve is not fully open) and top end HP (the valve is wide open). I know the point you were trying to make with the headers, just thought I would mention that a system like that does exist and works awesome (hard to beat the performance #'s of the rocket bikes).

Royce

Read about EXUP at:
http://www.ohiosuperbike.com/andy/exup.htm

Interesting idea. Notice that the emphasis is on wave theory, the positioning of the valves is important, and has little to do with creating pressure by adding an external blockage, like a muffler. My header calculator program displays the negative (good) and positive (bad) wave ranges of the headers it recommends, and the standard 28-30” header primaries have a positive wave in the range of 2500 to 4000 rpm’s, with a negative wave in the 6000 to 7800 rpm range. So you take a set of Hooker Comp headers, a XE274 Cam and a 2500 stall converter, where are you with your torque curve? You are accelerating through the worst performance of your exhaust and never get to the best. If you were to extend the primaries to 40+ inches, the positive wave occurs from about 1500 to 2900 rpm’s with the negative wave from 4000 to 5800 rpm’s, a situation that would increase the torque considerably.

Do you guys think my car will be noticeably faster once I get posi and at least 3.55 gearing? I guess I'm just really disappointed at the moment because my old 250 HP setup with my 350 would out run my current one with all the good parts I have. I didn't have a stall converter before though. I tried to locate my code on the rear end to figure out what gears I have,but didn't have any luck.Is that the only place where you can check that? I think they are really high.

Luke, its been said many times already. You have too much cam for those gears, period. Either tone the cam down, or go with lower ratio gears, such as 3.73's.

Dave

I thought I was going to have my gears and posi in before the motor was up and running,but unfortunately this didn't happen.I got under my car this morning and found the code stamped into the rearend. It has 2.73s http://www.camaros.net/forum/frown.gif ,so that diffently is not close to what I need for the cam/stall. I'm try and get some estimates on getting this auburn posi unit with richmond 3.73s in.Anyone know a ballpark figure of how much this normally costs. I'm just putting the unit and gears in my existing 10bolt.Thanks guys for replying,I'm sure the difference will be noticeable once the gears match up with the cam/stall