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Mid range foot response

themantis

themantis

New member
[1999 Grand Prix GTP] I have a 3" stainless steel Magnaflow exhaust, what should I plan on to improve mid range torque (xxxx-3700) and at 4200+ rpm my hp continuously falls slightly. Any suggestions?

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We make peak horsepower at 5000+ rpm, so if you are really losing horsepower past 4200, your motor isn't doing so hot.

I bet you are just noticing the torque drop off as the rpm rise. 0-80ish on a stock vehicle is about they got, past that and it takes forever to gain speed.


Headers move the power band slightly and the only real way to gain big torque is to add a camshaft and drop pulley sizes.
 
Fivefingerdeathpunch said:
We make peak horsepower at 5000+ rpm, so if you are really losing horsepower past 4200, your motor isn't doing so hot.

I bet you are just noticing the torque drop off as the rpm rise. 0-80ish on a stock vehicle is about they got, past that and it takes forever to gain speed.


Headers move the power band slightly and the only real way to gain big torque is to add a camshaft and drop pulley sizes.
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I'm at work atm, let me post the dyno results when I get home tonight. The only thing I remember positively is max torque occurred at 3900 (3rd gear). I just don't like having to rev to that to accelerate with any significance

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Scottydoggs said:
headers cam e85 little pulley, ic, pick one or all of em lol
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Exactly what I had planned. What do you mean by ic? And although it's largely opinion, is a cai a worthwhile consideration at this stage in building my car?

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intercooler after adding this second gear has a reason for life, aka it now pulls real hard in second gear.

006_zpsojx9yhgp.jpg


cai is about worthless, its good to hear the sc whine. may kill mph due to yo want to hear it whine lol
 


This was my stock 2000 GTP dyno that I had done.

Crappy picture but it still shows it's make power to 5200 rpm or so, I took this picture years ago and I don't remember if I have any others with a better print out.

2011-12-02141223.jpg
 
Scottydoggs said:
intercooler after adding this second gear has a reason for life, aka it now pulls real hard in second gear.

006_zpsojx9yhgp.jpg


cai is about worthless, its good to hear the sc whine. may kill mph due to yo want to hear it whine lol
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Intercooler, interesting. Everything I read about them said they created nothing but a whole new system the engine had to create pressure for, actually dropping power output. But maybe just top end. Cai is overrated :p

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themantis said:
Intercooler, interesting. Everything I read about them said they created nothing but a whole new system the engine had to create pressure for, actually dropping power output. But maybe just top end. Cai is overrated :p

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Click to expand...

thats pretty false. its the only way to drop pulleys on pump gas.
 


Fivefingerdeathpunch said:
Your dyno graph looks good, horsepower is on the rise to 5000+ rpm, just like normal.

Your torque curve is the higher graphed lines.
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Yeah sorry I was typing before without having the graph for reference. What I'm angry about is that I spent $1000 on that exhaust system to only raise horsepower by one . However I also realize that it was necessary to be able to support everything else I would do thereafter

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Scottydoggs said:
thats pretty false. its the only way to drop pulleys on pump gas.
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Good to know. What brand intercooler would you recommend? Also how do you feel about speed daddy headers, and how aggressive should I be with cams?

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The stock 2.25in catback exhaust can handle 300-350whp, that's basically why you didn't gain anything.

And $1,000 just for a simple catback sounds way overpriced.
 


Yeah I know, that's why I was upset I got it. What I had before was burst seamed mufflers and rusted pipes through and through. It sounded absurdly loud, and look up 3" stainless steel Magnaflow catback. They are $1,000 online, but I had Tim's Custom Exhaust make parts specific to my car for $600 and labor to install for $400. High flow cat is on my wishlist along with matching downpipe, but I need power to make it worthwhile 😂 I was lied to when I bought my car, being told it already had 300 whp proven by dyno last year. That's why I figured the exhaust was plausible, because I thought I only had room for 50 hp more.
Fivefingerdeathpunch said:
The stock 2.25in catback exhaust can handle 300-350whp, that's basically why you didn't gain anything.

And $1,000 just for a simple catback sounds way overpriced.
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LOL, I didn't even catch the name of the dyno sheet at first. I took my car to DB performance for mine aswell, just 3-4 years ago. But I never went back after I did my mods and tuning the car myself.

I live 3 miles from the shop here in Rogers.
 
Fivefingerdeathpunch said:
LOL, I didn't even catch the name of the dyno sheet at first. I took my car to DB performance for mine aswell, just 3-4 years ago. But I never went back after I did my mods and tuning the car myself.

I live 3 miles from the shop here in Rogers.
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I like what they have going on there, but I'll also admit I'm influenced by all their good reviews :p I'm 20 minutes from Rogers in Anoka

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