Ad Radar
123 Last
Item Posts    Sort Order

why is this pig soo damn slow?

 
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 06/28/11 09:41 PM

I need some intelligent input from people that go fast.... Or at least know what it means to go fast...
Here goes......
1992 chevy camaro rs...
408 *** sbc...
flat top pistons with 4 valve reliefs.... I'm guessin 11.0:1
brodix race-rite 200 heads with 2.08, 1.60 valves... 67cc chambers(I think)
comp extreme energy solid roller cam xr286: 248, 254 dur. .576, .582 lift, installed at zero.
springs and pushrods and all associated hardware matching per comp recomendations
1.5 ratio roller rockers
swapped from a port matched team "g" intake to a air gap rpm intake...1206 gasket
780 cfm holley 4160 vaccuum secondaries... I forget what jets are in it. plug check reads light tan
1 5/8" full length headers with 2 1/2" true duals with 2 flowmaster 40 series mufflers. fuel pump and regulator are holley 110 gph with big lines... I think its set at 7 1/2 lbs.
full msd ignition with 6al2 box... 18 degrees intial, 36 degrees total.
700r4 trans with all the good stuff in it.
3000 stall converter
4.11 gear
26 inch tire
Cam quest simulator (which i know is no where near real world) puts my output at around 590 hp @ 6000 rpm and 550 ft. lbs. torque at like 4000 rpm....
Theoretically this car should haul major ass, correct? This car will run a best of 8.4 secs in the 1/8.... I forget the mph... Best on a 150 shot was 7.5 at 90 somethin mph...
The car is not gutted but its got a glass hood with the cruise and stuff removed. I know these cars are heavy... This car just doesnt have the power I feel it should have for whats in it.. I have not cut any corners in building it and I havent ran it at the track recently but drive it on the street alot andI am thoroughly not impressed... It pulls steady from bottom to top(6700 rpm) with no bogs or hesitations but it just feels no where near what it should feel like... Am I just expecting way to much out of this car? Any body see any issues with my set up?
Please, any experts chime in with opinions, questions, or critisisms.... Before I scrap this heap....  
...You can only go as fast as your wallet will let you...

Post Reply
devine69
V-6 Camaros rule!
Posts: 88
Joined: 01/11
Posted: 06/28/11 09:49 PM

comp is a lost flats with4 flycuts  is low --need a 11-5 plus piston--go with at least a 12-5 with the heads  
old school racing--god bless us all

Post Reply
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 06/28/11 09:55 PM

My cranking pressure is about 190-195 psi per cylinder.... Is that still to low? Also forgot to mention the cam has a 110 lobe sep.  
...You can only go as fast as your wallet will let you...

Post Reply
Pontiacman2
Moderator
Posts: 8956
Joined: 09/08
Posted: 06/29/11 06:37 AM

Have you tried a little more timing?

That cam probably wont put out its beneficial power until at least 7500 RPM.
Not to sure about the rpm intake being the right intake for this combo.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

Post Reply
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 06/29/11 07:29 AM

the operating range for the cam suposedly is only up to about 6800-7000 rpm... the guys at comp say on a 400 it will only be about 6700ish. Only reason I swapped from the team g intake to the rpm air gap is after talkin with different tech lines they agreed i would benefit from the dual plane more... When I punch the equation into the Fairytale CAMQUEST simulator i pick up alot more power going from the single plane to the dualv plane... As far as more timing.... I'm running on pump gas and havent heard to many folks runnin much over, say, 38 degrees total... I'm sure it would love a degree or two more but detonation would suck....  
...You can only go as fast as your wallet will let you...

Post Reply
Pontiacman2
Moderator
Posts: 8956
Joined: 09/08
Posted: 06/29/11 08:29 AM

Ya if running pump gas keep the timing on the conservative side because even with aluminum heads 11:1cr is the max. safe limit for pump gas.

If the cam RPM range is correct then the rpm intake should work better just figured a cam like that would have more rpm potential.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

Post Reply
tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 06/29/11 08:56 AM

A knock sensor might be a good idea if dialing in more total advance.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Post Reply
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 06/29/11 10:00 AM

I'm pretty sure I wont see much of a gain even with a 2 degree advance.... This thing feels like its missing 100 horsepower.... Maybe I'm a lil exaggerated but the fact remains that this motor for what is in it aught to be rather healthy... I would think this thing should be a handful in the street.... oh yea and before the real technical questions start coming out, I have verified that my ign. timing is not flucuating with rpm due to cam walk... SO.... Any body got any realistic idears? Or should I scrap it and buy a ls1 car?  
...You can only go as fast as your wallet will let you...

Post Reply
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 06/29/11 09:34 PM

Are there no serious techies on board? c'mon... i know there has got to be some fast boys on here... i guess i will run it this weekend and get a new baseline.... checked my jets tonite... had 72 in the front and 78 in the back.. swapped up to a 75 front and 80 rear. actually felt a wee bit spunkier... checked timing... 18 initial, and 37 total...  
...You can only go as fast as your wallet will let you...

Post Reply
Dave632
I mow my lawn and find Chevys
Posts: 2253
Joined: 07/08
Posted: 06/30/11 03:55 PM

You did not give your mph in the 1/8th. This is always a good indicator of power being made. ET can be effected by many things. It also seems to me that your stall is kind of low. If you are using this car for mostly drag racing I would go for a stall in the 4500 range. For street strip you may have to stay where you are.
I have never been a fan of those power simulators and have had terrible results with them. Maybe the newer ones are better I don't know.
The weight of your car can be a huge factor, I would get it weighed to see where you stand. Here is an example: I took a BB Chevy out of a 3025 lb Nova, (all weights are with driver), and put it in a 2350 lb dedicated professionally built race car. It picked up 8 tenths in ET and almost 15 mph. 6.40-5.60 and 105-120 mph in the 1/8th.

Personally I would estimate you should be in the 400 horse range. This should put you around 86-88mph in the 1/8th at roughly 3500 lbs weight.
I had a street driven 95 Camaro that had some mods and it ran 86 mph in the 1/8th. I estimated that it was making roughly 375hp with the weight it was carrying.
The Nova I mentioned had a small block in it at one time and it ran about 88 mph in the 1/8th with an ET of 7.90-8.20 depending on conditions. This car hooked well and was geared with a 4.56/TH350 combo. Its weight was in the 3200 lb range at that time. It had a 350 with 2x4s ported heads and a flat tappet cam at that time. I would estimate that your motor should make a little more power than that one, (the 2x4s were worth about .5 sec. over a single 4 in that car), but your weight may make you slower than that combo.
I have drag raced for many years with many combos and found that it is not easy to go quick. The right combination is very important. I remember taking the 350 out of that Nova, putting in a 440 inch BB and I went much slower by about a second. I immediately ripped the trash oval port heads and intake that was on that BB and changed all that junk eventually running about 1.3 seconds faster than the SB did.  
[[SUPPORT AMERICAN CARS, STOMP A RICE CAR TODAY.]]

Post Reply
thaynes1472
I love my Chevy Chevette!
Posts: 1
Joined: 07/11
Posted: 07/03/11 08:01 AM

What u need my friend is a dyno. Dynos are great for bragging rights but racers know it is good for soooo much more. If all your parts are installed correctly then your car will run smoothly and consistently and you will make very good torque from about 2500RPM to about 4000 but it takes a bit more finess to make horsepower. First step to making horsepower is understanding what it is. alternatively you can find someone else who does and give them access to your bank account.

 Every tech article and every parrot who read one will tell you hp is tqxRPm/5252 but very few can tell you why. you see, hp is torque applied at speed. if there is no motion then there is no horsepower. if you put a torque wrench on a bolt you can apply 80ft-lbs of tq. that coincidentally is about the same as a geo metro but because you cant apply it at a rate of 3000 rpm you cant push a geo at 60mph. You REALL need to understand this concept in order to understand and in turn increase horsepower.

 Now, lets make some power. you will need to run your car on a dyno at least a couple times to see where the bottleneck in your system is. you will need a vacuum gauge attached to the intake, a pressure gauge attached to the exhaust as close to the manifold as possible and a wideband 02 sensor. When you make your initial run you need to look at where your torque starts to fall off and what happens to make it fall off.
 If you notice a sudden increase in vacuum in the intake manifold then you will need to first increase your throttle body diameter. In the case of a carburetor, you will need a larger carb. This will increase the flow into the engine and allow you to maintain torque at a higher rpm. remember, the faster you can apply the torque the more horsepower. I can see the grin on your face already.
 If there is a noticeable increase in pressure in the exhaust then you will need to invest in some headers and larger diameter exhaust. you want a smooth consistent exhaust system to help with scavenging. a topic we wont get into here.
 If you notice that your engine is leaning out where the torque drops off then you will need more fuel. larger injectors, larger needles, stuff like that.
 Here is where it gets complicated. if none of these apply then you most likely have a head design problem. You will need to look into high flow heads, cam, maybe a valve job.

 You can follow these simple rules fixing 1 bottleneck at a time till you get to about 7000rpm. Keep in mind that a good running engine that can produce 400ft-lbs of torque @ 7000 rpm will make over 530hp and thats nothing to laugh at unless you are the one driving.


Good luck. Let me know how things turn out.  

Post Reply
redneckjoe69
I mow my lawn and find Chevys
Posts: 2337
Joined: 03/10
Posted: 07/03/11 11:52 AM

awesome explanation.       your times arent that bad.   i think your suffereing from a few problems.  1st,  you need some better tire.   i have a 3rd gen & it hates to hook at all.  26s,.... Tongue        im thinking your compression is alot lower than you think, with flat tops & 67cc chambers, you might have 10.1.      your cam appears way more aggresive than the advertised duration.  definetly not street friendly, great for the strip & would love the stall that dave mentioned.   JMO, its overcammed for street use.     been there myself,....sounds cool,....but kinda dogish around town,....til ya hit 4,000 rpm.    maybe some carb tuning would help also?       i just think you coughed up alot of bottom end grunt with that cam & thats why you dont feel it in the seat of your pants.   no pig though. lol.  

Post Reply
mr.poindexter
I love my Chevy Chevette!
Posts: 2
Joined: 07/11
Posted: 07/03/11 11:12 PM

what secondary spring are you running in the Holley?    it may be coming in too slowly.  

Post Reply
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 07/04/11 09:06 AM

Icon QuoteDave632:
You did not give your mph in the 1/8th. This is always a good indicator of power being made. ET can be effected by many things. It also seems to me that your stall is kind of low. If you are using this car for mostly drag racing I would go for a stall in the 4500 range. For street strip you may have to stay where you are.
I have never been a fan of those power simulators and have had terrible results with them. Maybe the newer ones are better I don't know.
The weight of your car can be a huge factor, I would get it weighed to see where you stand. Here is an example: I took a BB Chevy out of a 3025 lb Nova, (all weights are with driver), and put it in a 2350 lb dedicated professionally built race car. It picked up 8 tenths in ET and almost 15 mph. 6.40-5.60 and 105-120 mph in the 1/8th.

Personally I would estimate you should be in the 400 horse range. This should put you around 86-88mph in the 1/8th at roughly 3500 lbs weight.
I had a street driven 95 Camaro that had some mods and it ran 86 mph in the 1/8th. I estimated that it was making roughly 375hp with the weight it was carrying.
The Nova I mentioned had a small block in it at one time and it ran about 88 mph in the 1/8th with an ET of 7.90-8.20 depending on conditions. This car hooked well and was geared with a 4.56/TH350 combo. Its weight was in the 3200 lb range at that time. It had a 350 with 2x4s ported heads and a flat tappet cam at that time. I would estimate that your motor should make a little more power than that one, (the 2x4s were worth about .5 sec. over a single 4 in that car), but your weight may make you slower than that combo.
I have drag raced for many years with many combos and found that it is not easy to go quick. The right combination is very important. I remember taking the 350 out of that Nova, putting in a 440 inch BB and I went much slower by about a second. I immediately ripped the trash oval port heads and intake that was on that BB and changed all that junk eventually running about 1.3 seconds faster than the SB did.


I think my mph on motor was like 85 mph.. but tthat was a loong time ago.... totally diff setup actually....... the track is still down from the tornado damage so i gotta wait to get new numbers... your mention of numbers bothers me on the hp side... What I dont understand is i ran this same car down the track with a stock internaled 350 with some procomp heads and a solid flat tappet comp cam .555 lift with a unported dual plane and a 600 carb i stole off my ole truck and it went 8.50 at 85 and 7.50 at 95 on the sauce.... as a matter of fact, i pulled like ten degrees timin out on the spray cuz i forgot my timing light and just cranked it back till it would barely idle and sprayed away lol.... the k$n filter was so stopped up on it that it wouldnt start the next day till i pulled the filter off lol.... The car "feels" no faster than that ole junk yard motor setup.... hell, i would think the 59 cubic inch difference would give it a wee bit more *** not to mention the marage of high dollar everything i put on with it.  
...You can only go as fast as your wallet will let you...

Post Reply
rednose-pit
V-6 Camaros rule!
Posts: 50
Joined: 07/10
Posted: 07/04/11 09:14 AM

dave632, Also.... r u figuring 400 at the wheels or the crank? I would certainly hope a 400+ inch small block with good heads and a healthy cam could spit more hp out of its flexplate even runnin not quite right..  
...You can only go as fast as your wallet will let you...

Post Reply
123 Last
TO TOP