xfi 292
04-25-2010, 02:53 PM
#21
Staging Lane
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Not what you want to hear but if that cam peaked at 6000rpms then either the valvetrain is really really bad or the heads are absolute garbage in order to choke it at so low an rpm.
It is widely recognized Comp's rpm ranges are WAY low because they use old school SBC rules from engines with long runners.
In an LT1 383 with good heads and a well spec'd cam say mid 330s will peak up around 6500 and make good power to 7000.
You know your car has problems, if you get bent out of shape when someone says that then the forum wont be able to help much.
It is widely recognized Comp's rpm ranges are WAY low because they use old school SBC rules from engines with long runners.
In an LT1 383 with good heads and a well spec'd cam say mid 330s will peak up around 6500 and make good power to 7000.
You know your car has problems, if you get bent out of shape when someone says that then the forum wont be able to help much.
04-25-2010, 03:02 PM
#22
Staging Lane
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MY tach has a shift light I built my car myself except for the paint.this car was built in rememberice of my brother who past 3 years and it was his car so I saved for 3 years sold a 66 396 chevelle to build this car when some dumbass tell you you screwed its a slap in the face. I am not a expert engine builder but I try. I was told wrong on another forum I changed to this forum.and I thank everyone that is trying to help me.
04-25-2010, 03:16 PM
#23
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there is something wrong with your set up. my firebird had the xfi 268 cam in it on 9.8:1 comp and ran 13.1-13.3 @ consistent 109's. the car was a STOCK stall and 2.73 gears. so either you completely lit up your tires in first and second.........or your heads are just choking the hell out of your motor.
04-25-2010, 03:40 PM
#24
I have never assembled a shortblock BUT I have done enough topends that walk strokers to know I have a clue as to what works.
People don't like my presentation but often in the end realize the INFORMATION was spot on. I get a lot of "you were right about everything" emails and PMs from guys who got all bent out of shape when I said they were doing things wrong.
Can the OP post a dyno graph. I wonder if the valvetrain is just not handling it because that cam should spin higher, even on stock untouched heads. This would be about best case scenario, maybe a $200 set of spring will get you 600rpms or so and get it to actually make power.
04-25-2010, 05:03 PM
#27
I have never assembled a shortblock BUT I have done enough topends that walk strokers to know I have a clue as to what works.
People don't like my presentation but often in the end realize the INFORMATION was spot on. I get a lot of "you were right about everything" emails and PMs from guys who got all bent out of shape when I said they were doing things wrong.
Can the OP post a dyno graph. I wonder if the valvetrain is just not handling it because that cam should spin higher, even on stock untouched heads. This would be about best case scenario, maybe a $200 set of spring will get you 600rpms or so and get it to actually make power.
People don't like my presentation but often in the end realize the INFORMATION was spot on. I get a lot of "you were right about everything" emails and PMs from guys who got all bent out of shape when I said they were doing things wrong.
Can the OP post a dyno graph. I wonder if the valvetrain is just not handling it because that cam should spin higher, even on stock untouched heads. This would be about best case scenario, maybe a $200 set of spring will get you 600rpms or so and get it to actually make power.
put a few heat cycles on the valve springs and i'd say let it rip. Then again you'll probably float the valves pretty bad spinning to 7k so don't do that.
04-26-2010, 11:47 AM
#29
I run the smaller XFI in my 383 (268 with 218/224 duration) and found the 26918 bee hive spring (as noted on cam card) keeps the valvetrain in order at high RPM's
your combo should yeild more power on the dyno. Your parts are what you have so confirm they operate as well as they can (springs, tune) and you should see better results.
your combo should yeild more power on the dyno. Your parts are what you have so confirm they operate as well as they can (springs, tune) and you should see better results.
04-26-2010, 12:44 PM
#35
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Iam not bitching I was just curous about my cam #'s And y'all dumbasses have to be cmplete **** like a mustang guy would be came on here advice not to be put down Iam well aware my setup is wrong If you are going dick and act ike a mustang owner stay off of this tread.
04-26-2010, 01:04 PM
#39
You are exactly right. No one here has taken any time to provide you with ANY information you could use, except for the few quotes below.
Are you reading any of this? More importantly, comprehending? Your biggest problem is that you're afraid of your car. You won't give the motor the RPMs it needs because you're afraid of what, it's going to blow up? Then why did you build it? My motor had about 10 minutes of run-time on it before I started going WOT.
Quit whining and go beat on it.
Are you reading any of this? More importantly, comprehending? Your biggest problem is that you're afraid of your car. You won't give the motor the RPMs it needs because you're afraid of what, it's going to blow up? Then why did you build it? My motor had about 10 minutes of run-time on it before I started going WOT.
Quit whining and go beat on it.
My peak hp was @ 6000 and tq was @4500 I launched @ 2000 also and still blow the tires. Iam wondering if I should change my setup or work with what I got and fine tune it.The guy that tuned my car is a real dumb *** but I live in coastal NC and dont have many tuning options.I got a grand in tunning and I know its still not right.
No i know I have problem but when someone like you tells someone else they screwed up bad is a smart *** remark( you should own a Mustang) My car is a street car not a drag car I cant just go out and buy heads and stuff I was told this cam would work great with my setup but now Iam hearing a differant Iam on a buget I have built my car since last nov. thats from stock black paint and a blow up motor to how it sits now I beleave I did a damn good job.Now I just got to get the bugs worked out .
Dyno numbers don't mean alot. They are only good for comparing what one pull does relative to another. Track times will tell yu what you need to know. Dynos depend on many factors like torque convertor, dyno setup, etc.
I have seen many people have a dyno sheet that says they should kill me, but neither my car or I are afraid of a sheet of paper other than the time slip when we compete.
Take it to the track
I have seen many people have a dyno sheet that says they should kill me, but neither my car or I are afraid of a sheet of paper other than the time slip when we compete.
Take it to the track
if the race weight is 3650 it takes 328 rwhp to go 13.0
I suspect spinning in first and second cost you alot of HP, and shifting at 5800 is probably leaving some on table. Get some slicks and try again the setup is definately healthier than that time. I suspect you can get 12.2 which woud be he hp you expected.
First time at track is never good, and hopfully dyno got it safe. Trailer the car and let her riip
I suspect spinning in first and second cost you alot of HP, and shifting at 5800 is probably leaving some on table. Get some slicks and try again the setup is definately healthier than that time. I suspect you can get 12.2 which woud be he hp you expected.
First time at track is never good, and hopfully dyno got it safe. Trailer the car and let her riip
Well, without even running the numbers, and even with you having more cubes, I'd guess that you don't have enough compression to be running that cam. This is a situation where the CC306 that you mentioned probably would be a much better choice.
I suggest looking into a custom ground XFI cam that has around the same advertised duration as the cc306.
I suggest looking into a custom ground XFI cam that has around the same advertised duration as the cc306.
Your mph suggested 12.5 or 370 rwhp so with slicks and holding RPM 12.2 is possible. What RPM did the dyno say was peak hp? Hold gear past peak hp few cams will give its all when short shifting. I would guess a 383 and that cam would peak >6200
I think the cam would take and even like more cr but 11:1 shouldn't cause that big of a drop since you are about 10% low on hp and a point cr if you are lucky might get you 20 hp.
I would try it with slicks and holding the gears more then see where you are at.
Good luck
I think the cam would take and even like more cr but 11:1 shouldn't cause that big of a drop since you are about 10% low on hp and a point cr if you are lucky might get you 20 hp.
I would try it with slicks and holding the gears more then see where you are at.
Good luck
I'm running 383 cid 12.3 static CR. I ran that cam thru a few dynamic CR calculators and came up with 9.1. Its the cam that I'm running. I like it but you need a good valve train to control it. I'll be swapping out valve springs soon and adjusting the shift points a bit higher. My tune is mail order and other than some timing and shift point changes its pretty much the same. If your CR is going to stay at 11.0 you might consider a different cam. FWIW.
Mec
Mec
Your setup is not optimal, but it is in there and already paid for. Get slicks, shift at 6400 and look at datamaster file. Use a shift lite I got s cheapie from Summit ~$40 and it is adjustable.
Send the datamaster file to me I will help you get it right you can always put another cam in it, but do it after you at least try the cam agin at the track.
CR will improve ~2% a point, but you are >10% low there is more wrong than the cr. You should get more with less cam I agree, but is it worth the expense?
Reground cam $125, intake gaskets, water pump, messing with oil pan etc and in the end you will likely get ~400 RWHP and you can reach that with what you have now,
The heads are likely going to be your restriction so unless you are willing to almost start over stick with what you have. It's easy to spend someone else's money, but I don't like to spend money even when it is yours.
If you can send a datamaster file and tune I can see how bad your tune is. A second or third gear pull will do it.
Good luck
Send the datamaster file to me I will help you get it right you can always put another cam in it, but do it after you at least try the cam agin at the track.
CR will improve ~2% a point, but you are >10% low there is more wrong than the cr. You should get more with less cam I agree, but is it worth the expense?
Reground cam $125, intake gaskets, water pump, messing with oil pan etc and in the end you will likely get ~400 RWHP and you can reach that with what you have now,
The heads are likely going to be your restriction so unless you are willing to almost start over stick with what you have. It's easy to spend someone else's money, but I don't like to spend money even when it is yours.
If you can send a datamaster file and tune I can see how bad your tune is. A second or third gear pull will do it.
Good luck
Not what you want to hear but if that cam peaked at 6000rpms then either the valvetrain is really really bad or the heads are absolute garbage in order to choke it at so low an rpm.
It is widely recognized Comp's rpm ranges are WAY low because they use old school SBC rules from engines with long runners.
In an LT1 383 with good heads and a well spec'd cam say mid 330s will peak up around 6500 and make good power to 7000.
You know your car has problems, if you get bent out of shape when someone says that then the forum wont be able to help much.
It is widely recognized Comp's rpm ranges are WAY low because they use old school SBC rules from engines with long runners.
In an LT1 383 with good heads and a well spec'd cam say mid 330s will peak up around 6500 and make good power to 7000.
You know your car has problems, if you get bent out of shape when someone says that then the forum wont be able to help much.
there is something wrong with your set up. my firebird had the xfi 268 cam in it on 9.8:1 comp and ran 13.1-13.3 @ consistent 109's. the car was a STOCK stall and 2.73 gears. so either you completely lit up your tires in first and second.........or your heads are just choking the hell out of your motor.
I have never assembled a shortblock BUT I have done enough topends that walk strokers to know I have a clue as to what works.
People don't like my presentation but often in the end realize the INFORMATION was spot on. I get a lot of "you were right about everything" emails and PMs from guys who got all bent out of shape when I said they were doing things wrong.
Can the OP post a dyno graph. I wonder if the valvetrain is just not handling it because that cam should spin higher, even on stock untouched heads. This would be about best case scenario, maybe a $200 set of spring will get you 600rpms or so and get it to actually make power.
People don't like my presentation but often in the end realize the INFORMATION was spot on. I get a lot of "you were right about everything" emails and PMs from guys who got all bent out of shape when I said they were doing things wrong.
Can the OP post a dyno graph. I wonder if the valvetrain is just not handling it because that cam should spin higher, even on stock untouched heads. This would be about best case scenario, maybe a $200 set of spring will get you 600rpms or so and get it to actually make power.
i don't like you, but i agree with what you say most of the time. in this case its one of the few threads i completely agree with you. FWIW I made 100 rwhp more than this guy at only 5400 rpm because of valve float, it ended up costing me about 40 rwhp and 1000 rpm. His heads are probably complete junk, with other major problems including the tune, and that cam being shitty.
I run the smaller XFI in my 383 (268 with 218/224 duration) and found the 26918 bee hive spring (as noted on cam card) keeps the valvetrain in order at high RPM's
your combo should yeild more power on the dyno. Your parts are what you have so confirm they operate as well as they can (springs, tune) and you should see better results.
your combo should yeild more power on the dyno. Your parts are what you have so confirm they operate as well as they can (springs, tune) and you should see better results.
04-26-2010, 01:05 PM
#40
to the OP..
as you see there are many 'opinions" and some with more pepper in them that you may like.
The cam you picked wants to see higher RPM's than others to make it's max HP so your valve train needs to be set up to allow that. Not saying it is not now but without the spring info (installed height, spring specs) it is hard to comment accurately. Your heads are also somewhat of an unknown in terms of what they actually flow and valve size (if not stock).
Valve train geometry also needs to be spot on not only for prformance but longevity.
dyno graph would show signs of valve train break up so posting it would help.
You are correct in not spining the motor to 7k if there are uncertainties in the motor/valve train. If that stuff checks out running to a higher RPM on shifts should improve times.
Dyno readings can be all over the place compared to other dynos. Mustang dynos are known to show low #'s and DynoJet higher compared to a Mustang.
MPH is a strong indicator of HP
as you see there are many 'opinions" and some with more pepper in them that you may like.
The cam you picked wants to see higher RPM's than others to make it's max HP so your valve train needs to be set up to allow that. Not saying it is not now but without the spring info (installed height, spring specs) it is hard to comment accurately. Your heads are also somewhat of an unknown in terms of what they actually flow and valve size (if not stock).
Valve train geometry also needs to be spot on not only for prformance but longevity.
dyno graph would show signs of valve train break up so posting it would help.
You are correct in not spining the motor to 7k if there are uncertainties in the motor/valve train. If that stuff checks out running to a higher RPM on shifts should improve times.
Dyno readings can be all over the place compared to other dynos. Mustang dynos are known to show low #'s and DynoJet higher compared to a Mustang.
MPH is a strong indicator of HP