LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Dynoed my 847 car today...

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Old 02-02-2008, 12:36 PM
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those numbers do seem low for a ported head car...

That single 3inch catback, that could be hurting you. you should upgrade to a 3.5 or 4inch single for that heads/cam combo. you need a better muffler too

Also, what valve springs are you using? are you experiencing any valve float? power should be climbing alittle higher than 6400 rpms i think. possibly loosing some power due to inadequate springs
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Old 02-02-2008, 12:47 PM
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Originally Posted by nes
did u dyno on dragradials??
275/40/17 MT DR's at 20psi hot.
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Old 02-02-2008, 12:52 PM
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Originally Posted by Orr89rocz
those numbers do seem low for a ported head car...

That single 3inch catback, that could be hurting you. you should upgrade to a 3.5 or 4inch single for that heads/cam combo. you need a better muffler too

Also, what valve springs are you using? are you experiencing any valve float? power should be climbing alittle higher than 6400 rpms i think. possibly loosing some power due to inadequate springs


I have bee-hive type springs, I don't remember exactly what springs they are at the moment.
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Old 02-02-2008, 01:21 PM
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Originally Posted by '94 Bad A Z28
275/40/17 MT DR's at 20psi hot.
from my understanding your numbers will read quite a bit lower from dynoing with dragradials, because they are harder to spin the drums, i know guys on svtperformance(im a mustang guy) had gained 20-30rwhp simply by taking off their mickeys and putting on some sumis... ill see if i can get more info on that for you, but i will say that dynoing on DRs isnt the way to go.
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Old 02-02-2008, 01:57 PM
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That's new to me, but any info would be appreciated. I'll dyno again on some street tires if it is going to get me higher numbers, lmao.
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Old 02-02-2008, 02:15 PM
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drag "radials" are no different than street radials on a dyno. They are a radial tire, and they do not change sizes on the fly. The reason you see lower HP numbers with a slick or DOT slick is that they change size and shape the faster they spin. You have to remember here, a chassis dyno like a Mustang or Dynojet do not measure HP. They only calcullate it by knowing the weight of the rollers, how fast you spin them up and how fast your engine spins. Did you ever notice that your HP and TQ numbers always cross at 5250rpm's? They all work the same way and only calculate hp from a given set of parameters.

There are soooooooo many variables to take into conideration. An engine dyno actually loads the motor up to determine actual HP. There are dynos out there that will load up the rollers and tell you actual HP but you will not see them in the automotive buisness.

Go to a truck shop. My work has a chassis dyno that they pull a truck onto and strap it down. They use it to actually load up a big rig drivetrain and see if there is a problem. You can load it up and hold any particular HP level you want for as long as you want.

Not the case for a chasis dyno that we put our cars on.

Its a tool to use not an actual measurement of HP.
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Old 02-02-2008, 03:07 PM
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Don't worry about those dyno numbers so much, my car dynoed 400rwhp and ran 11.00's@123mph but it was a Mustang dyno. go run the car and you will see if somethings not right.
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Old 02-02-2008, 03:10 PM
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If anything your track #'s are low for your dyno #'s. I went 12.5@111.0 with a slipping tranny and stock stall when i was only making 322rwhp (crane 227 cam and 240cfm heads) And those hp calculators are a joke.
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Old 02-02-2008, 04:23 PM
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Originally Posted by speed_demon24
If anything your track #'s are low for your dyno #'s. I went 12.5@111.0 with a slipping tranny and stock stall when i was only making 322rwhp (crane 227 cam and 240cfm heads) And those hp calculators are a joke.
Well lets see what you run with 420rwhp buddy. You want to run headsup since you make more HP?
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Old 02-02-2008, 04:41 PM
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Uh oh^^^^Sounds like Clint's throwing down the gauntlet...I'll run the winner.......or the loser...

--Alan
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Old 02-02-2008, 05:18 PM
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Originally Posted by ABA383
Uh oh^^^^Sounds like Clint's throwing down the gauntlet...I'll run the winner.......or the loser...

--Alan
Then who do I get to run!?

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Old 02-02-2008, 05:35 PM
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Sounds like fun guys, we can do 2 out of 3 or whatever. I am finishing up with a few adjustments I made to my car today. Then it's going to Madmans shop this week for a Wolfe adjustable swaybar, scaling it and setting up the suspension so we shall see what it will do next weekend if all goes well. Lets get it on. LOL
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Old 02-02-2008, 06:15 PM
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is this an official call out and confirmation?
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Old 02-02-2008, 06:36 PM
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How about we set something up like Hattiesburg mississippi? That track is not very strict on rules and is about a 3hr drive for me, since Florida is 7hrs. does that seems fair?
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Old 02-02-2008, 06:53 PM
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Originally Posted by Projectz28
Then who do I get to run!?

I'll need a big head start with you.......and probably one for Clint, too...

--Alan
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