N/A engine rebuild performance problems

ONLY for ADVANCED technical discussion about the 240sx!
danny_240sx
Posts: 7
Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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I had a ka24de built with the following mods to try to reach 200 whp and came back with a crappy 139 whp and 154 wt. The torque reaches peak at 4500 rpm and the horsepower at 5,500 rpm and then goes straight down. Does anybody have any idea why? Could it just be the tune, I'm buying a q45 throttle body and seeing what that does.KA24de fully rebuilt with:

Block bored .04 overEagle forged rodsKA24E flat top pistons (11:1)Ported and polished head3 angle valve jobHotshot headerAEM intakeMeagan exhaustBC stage 2 camsSR20DET 370cc injectorsTuned with Greddy E-manage blue

Modified by danny_240sx at 6:37 PM 4/12/2009

Modified by danny_240sx at 6:38 PM 4/12/2009
Modified by danny_240sx at 7:24 PM 4/12/2009


liquid_cool
Posts: 1700
Joined: Sat Jul 05, 2008 3:02 am
Car: 1990 Nissan 240SX KA24DE-T swap 8.6:1cr, duelsprings, ti retainers,supertech pistons, K1 H-beems balanced internals ect ect

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have ya tuned it on a dyno to set your fuel map for the emanage?..ohh and please post up the switch settings for your ka24de for the emanage:)..if you remeber you have to set the piggy up for every increment of 1000 rpm..as i understand it...you might have a hole in your fuel map...allso post up a pic on how ya have your emanage wired in please.

danny_240sx
Posts: 7
Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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I had the emanage tuned at Trackmasters in Huntsville, AL but I've heard from a couple people that they don't tune 240's very well. As for finding out the switch settings if you tell me how I will post them. It is wired up with a boomslang plugnplay harness. I can post the dyno if some1 tells me how to post a pic.Thanks.

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zstylelowrider
Posts: 28
Joined: Tue Jul 08, 2008 7:02 am
Car: 1995 nissan 240sx

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I NOTICED YOU UPGRADED YOUR INJECTORS BUT WHAT ABOUT YOUR FUEL PUMP?

danny_240sx
Posts: 7
Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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No, I didn't change the fuel pump because it had a new one installed by Nissan 2 years ago. I thought that the stock fuel pump could handle those injectors because the Greddy turbo kit for this car doesn't require you to change your fuel pump but comes with 370cc injectors.

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Drift40
Posts: 19
Joined: Wed Jul 09, 2008 1:21 pm
Car: 96' 240sx se

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my guess is it could be the tune because i have a motor built similar but stock cams, ecu, injectors, and 9:1 forged pistons and made 153 whp and 155 wtq. Mine seemed to drop off about the same rpm too. I thought maybe that was my cams? idk if this helps but id think you should be making more.

del82
Posts: 124
Joined: Tue Dec 30, 2008 8:15 am

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zstylelowrider wrote:I NOTICED YOU UPGRADED YOUR INJECTORS BUT WHAT ABOUT YOUR FUEL PUMP?
This here. Next time you dyno it, have em probe the exhaust to get the AFR during the dyno, if its leaning out in a hurry, its falling on its face from lack of fuel. If that's not the case, then just take it to a different tuner.

danny_240sx
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Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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Cool, alright well thanks for your input.

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480sx
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Joined: Sun Nov 12, 2006 5:27 pm
Car: 1996 Pearl White 240sx

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Lol @ thread. Shoulda done some research bud.. N/A ka hp isnt for the faint of heart, it takes a lot of knowledge skill and money to get anything out of the motors N/A.

You first need a real tuning system. Go with Nistune or a full stand alone. You need the ability to mess with timing maps along with real control over your fuel maps. A new tuner too.. If you'v heard they dont tune 240's well, then they dont tune well. Period.

Seriously, if you want your car to be anything, you have to ditch the Emanage and get either a Nistune chipped 'stock' ecu, or a full stand alone. Along with a good tuner.

danny_240sx
Posts: 7
Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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480sx wrote:Lol @ thread. Shoulda done some research bud.. N/A ka hp isnt for the faint of heart, it takes a lot of knowledge skill and money to get anything out of the motors N/A.

You first need a real tuning system. Go with Nistune or a full stand alone. You need the ability to mess with timing maps along with real control over your fuel maps. A new tuner too.. If you'v heard they dont tune 240's well, then they dont tune well. Period.

Seriously, if you want your car to be anything, you have to ditch the Emanage and get either a Nistune chipped 'stock' ecu, or a full stand alone. Along with a good tuner.
Do some research? I did a ton of research of the N/A KA motor and I know you have to do really extensive mods to get around 200 whp, but with my set up and a e-manage you should at least get 180-190 whp. I've looked up a couple cars on the forums that have about the same set up and got that much. I'm buying a new walbro fuel pump and see what that does. I didn't know that they sucked at tuning 240's until I talked around with some people after I got the car tuned, why else would i wanna waste 300 bucks !

danny_240sx
Posts: 7
Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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Also, just to prove to myself that it was the tune I bought, don't laugh, an Emance tuned ecu tuned for 11:1 compression w/bigger cams and 370cc injectors. NOW, I didn't google emance tunes until after I purchased it. Originally I thought I was buying an Enthalpy tune. Suprisingly though it runs really good. I decided to buy a new fuel pump because I noticed around the 5k rpm and up on both tunes seems to lose power. When I get the new fuel pump(it's on the way) I'll dyno it and let you know.

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480sx
Posts: 4085
Joined: Sun Nov 12, 2006 5:27 pm
Car: 1996 Pearl White 240sx

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Yea, your not hitting 180-190 hp with emanage alone. Sorry.

Emance has a horrible reputation, good luck with cheap option number two.

ka_240_drifter
Posts: 10
Joined: Thu Jan 29, 2009 8:57 pm
Car: 91 s13

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what MAF sensor are u running? fromwhat iv read in forums the stock G60 MAF droppes off power after 5000rpms (OR SO. iREMEMBER SOMETHIGN LIKE THAT.CORRECT ME IF IM WRONG) .. u should runn the N60 MAF.

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Leachguy
Posts: 45
Joined: Wed Jul 25, 2007 5:28 am
Car: S14 Zenki Starfire Blue

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Also that stock intake manifold on the KA's isn't meant for high revving horses. They were built more so for nice torque. That is part of your problem for the drop off.

danny_240sx
Posts: 7
Joined: Sun Apr 12, 2009 2:46 pm
Car: 1991 Nissan 240sx

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Yea that's true. Do you think one of the Xcessive intake plenums would help with that?

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Leachguy
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Joined: Wed Jul 25, 2007 5:28 am
Car: S14 Zenki Starfire Blue

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Oh, for sure but that would also require more tuning and would drop off your low end and you'd need to get to revving to make power. But that's more fun anyway haha.


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