Highest RWHP w/Stock Engine and Boost?
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 1,100
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From: Charlestown, Indiana
Yes, you pretty much have to have valve springs to make any significant power past about 5000 rpm's, IMHO. We've had cars with only 6000 miles that would fall on their face at anything over 475rwhp because of the weak valve springs from the factory.
Boost has a way of magnifying that problem.
Boost has a way of magnifying that problem.
TECH Resident
Joined: Jan 2002
Posts: 956
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From: Phoenix, AZ
OK, good! My car is dropping like a rock starting at 5200. I go from 575hp@5250 to 429@5800 . . . quite a drop at 146HP!! Torque at those RPM's also go from ( guess what?? 
) 575 to 392, which is a 168tq drop!!
Any guesses on what I'll get with some 918's in there?
- Dug
) 575 to 392, which is a 168tq drop!!Any guesses on what I'll get with some 918's in there?
- Dug
on a 2" valve with 11psi boost you are you looking at a reduced spring pressure of around 35psi? so that would reduce the stock seat pressure from 76 to 41#? and the spring recovers back to 76psi at .1066 valve lift? and the 918's will give you stock seat pressure at boost of 17psi? just doing some homework, but it applies here.. just need to know i'f my math is wrong.
or should i not assume the intake valve is the problem area and look at exhaust pressure instead of boost?
or should i not assume the intake valve is the problem area and look at exhaust pressure instead of boost?
ok by the same math if your exhaust/intake pressure ratio is 1.69 then the boost affects the exhaust spring and the intake spring the same psi... anything higher and the exhaust spring is more important and lower the intake spring is more important.. on a 2.0/1.55 set up is that right?
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Verdad Gallardo TECH Resident
Joined: Jan 2002
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From: Phoenix, AZ
I was hoping you'd say that 
So what you're telling me is that barring any other problems, I'm gonna be right up there with you for stock engine
BTW, what was your torque on stock springs?
- Dug
So what you're telling me is that barring any other problems, I'm gonna be right up there with you for stock engine
BTW, what was your torque on stock springs?
- Dug
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 1,100
Likes: 0
From: Charlestown, Indiana
Actually, my TQ barely changed. Before the springs, the highest we saw was 695rwtq. After the springs, one of the pulls was 701rwtq, but most were 690-697.
What was your car dynoing when you ran the 11.59 @ 119?
What was your car dynoing when you ran the 11.59 @ 119?
TECH Resident
Joined: Jan 2002
Posts: 956
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From: Phoenix, AZ
OK, well I won't be beating you in torque then!
The car had dynoed 533/567 on 10psi, the 11.59 @ 119 was same configuration but only 8.5psi. I tried 10 once that day and it kept blitzing the ET Streets. I figure that run would be in the neighborhood of 500/530. I have been trying to get to the track and get new times, the last 2 times I have gone it's either been rained out or something's wrong at the track!! My car's a pig too, 3800lbs with me in it. I have done no weight savings measures whatsoever yet.
- Dug
The car had dynoed 533/567 on 10psi, the 11.59 @ 119 was same configuration but only 8.5psi. I tried 10 once that day and it kept blitzing the ET Streets. I figure that run would be in the neighborhood of 500/530. I have been trying to get to the track and get new times, the last 2 times I have gone it's either been rained out or something's wrong at the track!! My car's a pig too, 3800lbs with me in it. I have done no weight savings measures whatsoever yet.
- Dug
Who cares what it dynos. Get'em to the track. Well once the ice melts.
Great numbers by all though.
Rob, I will be getting in touch with you soon about one of those alky inj. kits. I want to see how much one of these stock shortblocks can take.
Get'em to the track. Well once the ice melts.Great numbers by all though.
Rob, I will be getting in touch with you soon about one of those alky inj. kits. I want to see how much one of these stock shortblocks can take.
Well, it looks like i own this title for a little while longer huh?
600.1 rwhp, 636.4 rwtq on a dynojet.
Everything is stock in the motor, EVEN the springs, no alcohol injection 
This was showing 11lbs of boost on the dynojet.
Come spring, i will put it on the dynojet at the 13-14lbs we have had it at on the street.
I wish i knew how to post my dyno curves, but i did it at a dyno day, so there are a bunch of witnesses
Stenod
600.1 rwhp, 636.4 rwtq on a dynojet.
Everything is stock in the motor, EVEN the springs, no alcohol injection
This was showing 11lbs of boost on the dynojet.
Come spring, i will put it on the dynojet at the 13-14lbs we have had it at on the street.
I wish i knew how to post my dyno curves, but i did it at a dyno day, so there are a bunch of witnesses
Stenod
Last edited by Stenod; Jan 7, 2004 at 10:03 PM.
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 1,100
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From: Charlestown, Indiana
Originally Posted by BLACK02SS
Well, it looks like i own this title for a little while longer huh?
600.1 rwhp, 636.4 rwtq on a dynojet.
600.1 rwhp, 636.4 rwtq on a dynojet.
ya but he has stock springs so its a 100% stock motor.
now if he made the gains you did when switching springs.
one thing amazing about his dyno is his torque it is almost a flat line of 600rwt across the board.
black02ss if you can email me your dynosheet (mustang or dynojet) ill host it and put it up for you. jharder@norcold.com
now if he made the gains you did when switching springs.
one thing amazing about his dyno is his torque it is almost a flat line of 600rwt across the board.
black02ss if you can email me your dynosheet (mustang or dynojet) ill host it and put it up for you. jharder@norcold.com
Last edited by smokinHawk; Jan 8, 2004 at 10:46 AM.
TECH Resident
Joined: Jan 2002
Posts: 956
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From: Phoenix, AZ
Ooh, two Incons chasing top spot
I also have only dynoed on 91 octane so far . . . have not tried any race gas at all. So while I had alky, no race fuel . . . I'm sure you top dawgs dynoed with some, right??
I also have only dynoed on 91 octane so far . . . have not tried any race gas at all. So while I had alky, no race fuel . . . I'm sure you top dawgs dynoed with some, right??
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 1,100
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From: Charlestown, Indiana
Nope. I was running pump gas and alcohol only. We already determined springs were acceptable. Otherwise, the cars with 100,000+ miles would be at more of a disadvantage than the cars with low miles.
Originally Posted by ChevyNo1
Stenod, I figure you HAD to have race gas, didn't you??
I had race gas in the car, but i consider that pump gas too, **** i pull up to the gas pump and pump it in just like everyone else. with the good race gas, i don't even bother with the 11lbs, car runs better at 13
I read the title as 100% stock LS1. Well, Comp 918 springs are not stock!
Pretty sick the stock motors are handling the amount of abuse some of us crazy ***'s are throwing at them, the question is how long, and how far can we continue to push them.
Stenod