At A Loss With HP Dyno Numbers!!
Normally your duty cycle compared to target afr will show you the need. You dont know that part so you cannot choose based off that, but every combo like yours ive seen (even with those low numbers) has needed them.
We carry the fast36 which are actually 42lb at 58psi. they are $300 fit perfect and are easy to tune and idle perfect.
We carry the fast36 which are actually 42lb at 58psi. they are $300 fit perfect and are easy to tune and idle perfect.
Yes electric cutouts are relatively cheap now. I just don't like that I wouldn't be able to drive with them open on the streets without possibly getting pulled over. Seems kind of useless to just use it on a dyno, well and possibly car gatherings too. I've looked at a few Maganflow catback systems and they are kind of expensive.
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Hello ddnspider, it's not that I'm not listening to all that have replied to my post. I appreciate everyone who has. There are just some things that I do not want for my daily driver. An obnoxiously loud exhaust to where I get droning, neighbor complaints, etc. and of course having it not so driver friendly at low speeds due to most of my driving is in the city by possibly getting a bigger cam. I posted on here because of the knowledge and experience of the members here that I have seen over the years. I'm just trying to give the people that have replied an idea of what I have already and what I am wanting and not wanting and then get feedback from that.
Last edited by den_hart; Jul 17, 2017 at 07:24 AM.
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A Chevelle I built with a stock 5.3 other than 222/225 cam and speed engineering 1 3/4" long tubes made 312whp on a Dyno Dynamics a couple of months ago. Stock shortblock with new head gaskets, untouched 706 heads other than springs.
Stock truck intake and throttle body, stock MAF with an ebay intake/filter.
I dunno if that helps as a comparison.
Stock truck intake and throttle body, stock MAF with an ebay intake/filter.
I dunno if that helps as a comparison.
Why worry so much about a number on paper? If it bothers you so much take it to a place that can cheat the numbers to make it say whatever you want...hell go for 500RWHP. It's just a number and it will never mean a thing if the car doesn't see the track...or save your money and just TELL people it puts down XYZ HP. You can even print a dyno sheet someone else ran and carry it around in a frame so that when you tell people how much HP you have you can whip that out of the glovebox and show them...
OP, you need to do this. If nothing else, it would rule out the possibility. If you can change an air filter then you can check the throttle blade position. After a build similar to yours I made 370rwhp when I expected to make 400+. When checking everything after the dyno tune I noticed that the blade only opened up to 80%. After correcting, my car made 410 rwhp on the same dyno.
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Hello 98cherrySS. Thank you for your reply. I know the throttle not opening up all the way has been mentioned prior by a couple of other members. I will definitely keep that in mind. How did you go about correcting it if that is the issue? That is quite a difference!!
Damn! Nice observation! Yes it will. Simply changing rear gear from 3.42 to 4.11 has some small effect. By comparison, its like going from 3.42 to 6.1 gears to dyno in second. You're consuming HP to make wheel torque. It also loads the engine up differently - i.e less
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The tuner guy dyno'd my car in second gear back in 2016 as well. He said it was because my tires back then had sidewalls cracks in them. I told him Saturday that they tires have been replaced so that wouldn't be an issue. So are you guys saying that the car should be dyno'd in overdrive?
The tuner guy dyno'd my car in second gear back in 2016 as well. He said it was because my tires back then had sidewalls cracks in them. I told him Saturday that they tires have been replaced so that wouldn't be an issue. So are you guys saying that the car should be dyno'd in overdrive?
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I saw a picture of the dyno sheet of the guy that installed my LS6 intake and heads. It was tuned by the same guy and he is making 400RWHP with the converter locked and 382RWHP with the converter unlocked. His dyno sheet doesn't say anything about "second gear run". I also talked to the guy that did my upgrades back in December which included the 3200 stall converter about the converter slippage. He said it's nothing to worry about unless it was drastic. He is thinking it's due to the catback restricting flow. The guy that tuned the car the first time and then again this past Saturday said that a different catback MAY get me another 10HP to the wheels so my numbers would still be off.
I saw a picture of the dyno sheet of the guy that installed my LS6 intake and heads. It was tuned by the same guy and he is making 400RWHP with the converter locked and 382RWHP with the converter unlocked. His dyno sheet doesn't say anything about "second gear run". I also talked to the guy that did my upgrades back in December which included the 3200 stall converter about the converter slippage. He said it's nothing to worry about unless it was drastic. He is thinking it's due to the catback restricting flow. The guy that tuned the car the first time and then again this past Saturday said that a different catback MAY get me another 10HP to the wheels so my numbers would still be off.
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Darth I don't know what you mean about "Separate the Y from the I and dyno open" unless you are talking about doing a dyno run with the catback unhooked from the Y pipe and then compare the numbers with the catback hooked back up to the Y pipe. The tech guy that did my upgrades back in December suggested doing that. He's trying to get in touch with someone that he knows that is kind of local to see when we can bring my car in for some dyno time.
Darth I don't know what you mean about "Separate the Y from the I and dyno open" unless you are talking about doing a dyno run with the catback unhooked from the Y pipe and then compare the numbers with the catback hooked back up to the Y pipe. The tech guy that did my upgrades back in December suggested doing that. He's trying to get in touch with someone that he knows that is kind of local to see when we can bring my car in for some dyno time.
Dyno in third vs second will bring the power up a bit and the torque down a bit, which would be more in line with what you'd expect to see.
I still see some features that look "off" on the dynographs, as mentioned before, and I just don't think that anything discussed explains it - unless it's the throttle not opening all the way or the CAI air inlet collapsing between filter and throttle.
For ***** and giggles, you might also try this... Remove valve covers. Manually rotate the engine to TDC for cylinder 1. Try to wiggle pushrods. if they wiggle, you have a collapsed lifter. Then, rotate the engine to the next cylinder TDC (#8) and check pushrods, then 7, then 2,6,5,4,3. You find a loose pushrod, there's the whole problem.