Average increase

[Jonathanlc05]

I just bought a 97 eclipse GS with 98000 miles for 5 grand. it has a CAI and cat-back. what horsepower increase will i notice over stock.

 

[VelocitàPaola]

Maybe 10-15 hp (at the crank; and that's an optimistic figure).

 

[DSMcrazy3]

Little to none. All I noticed from mine when I installed my CAI was a throatier sound. The best mods for the price for 420a would be a bigger throttle body(you would need to get the plenuum ported to match) and a light weight UDP.

Eventually for the real power a 420a is capable of making, you're going to have to spend some money and go turbo, then eventually rebuild the bottom end and purchase a nice system to tune with.

For a nice reliable daily driver, with a little pep just stick with Intake, Headers, Exhaust, bigger throttle body and lightweight UDP.

 

[Jonathanlc05]

ok thanks. i use to have a 92 eclipse and familiar with those engines but not the 420a's. will they last long with those mods?

 

[VelocitàPaola]

Just the intake, exhaust, headers, TB, and UDP? Certainly! The 420A is an extremely reliable engine, and making those modification will in no way compromise that reliability.

 

[DSMcrazy3]

A lightly modified 420a makes a great reliable daily driver. Granted it has been taken care of. If the previous owner, or you have beaten on it, then don't expect it to be very good to you.

Run a compression test and give us the numbers. That's the best way to judge the condition of a motor. Without literally ripping it apart, that is.

 

[Jonathanlc05]

and does gas mileage still stay as good even to lets say 150k miles

 

[Jonathanlc05]

yeah ill do a compression check but it wont happen for like a month or 2 because i just pulled this loan yesterday and got the car today. it pulls very nice and almost as good as my passat vr6. any problems i should know about in the 97's? with the 92's i heard transmissions are weak (which i almost replaced till i wrecked it) and some electricals

 

[VelocitàPaola]

Gas mileage will gradually decrease in time, as with any car, but this effect should be negligible. With proper care (oil changes, filter replacements, etc.), the gas mileage should be near where it was when the car first rolled off the assembly line.

If the car pulls hard, and feels strong, that's a good indication that your compression is good; however, the only real way to know is by actually doing a compression test. You can pick up a simple pressure gauge to do this with at your local auto parts store (i.e. Advance Auto, Autozone, etc.).

Here's a tech article about checking the compression:
http://www.dsmtuners.com/forums/showthread.php?t=76227

 

[DSMcrazy3]

There's no reason a compression test should be put off for 2 months. You might have it mistaken, or have judged it as an expensive task, or tool to buy. As Paul stated you can get the compression test tool at a local auto parts store. Almost all of them will rent it out and give a full refund when you return it.

It's a very simple task, as stated in the write, up it's as easy as changing spark plugs. However, in the write up the pictures have been blocked due to size. So I took the liberty of taking an old pic of mine and circling the relays it mentions disconnecting.

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[XMasta19]

You did yourself a wonderful favor in buying that car...there's a vast wealth of knowledge around here, and don't be afraid to ask some questions either

 

[WMD]

Ill chime in about the CAI and exhaust. That difference is noticable and the two mods in junction will alter your horepower and torque curve noticeably. I observed this after my V2 and exhaust were put on:
At 80 mph, the totaly stock 420a eclipse will have an engine speed of 4000rpm. With the CAI and exhaust (2.5" + stock cat) instaled, the car now has an engine speed of 3500 to 3400rpm at 80mph.
This shows the horse power curve was shifted to the left, but it was also lengthend because of the noticable pull up into the higher rpm's (7000 ~ 7200redline). More torque is noticable but their is a loss in the lower rpm range. (around 1000 ~ 3000rpm).

Hope this helps to visualize the difference with the addition of a CAI and exhaust to a 420a.

EDIT: I'd also like to add that the extra "oomph" is not nessarly a large amount of more power, but a shift and reshapeing of the curves. I dont know the dyno numbers so I cant say it added x amount of power, but I can say it makes a difference in the way the car feels and drives.

 

[quiksilver38]

when i put CAI on my 420a Gs i noticed way better throttle responce not much more power though great comuter 24-30 mpg even with non rebuilt 167,000 miles didnt burn oil either

 

[XMasta19]

Most of the common mods are definitely great, we were just trying to point in the direction of the best bang for the buck out the box The AF/X UDP would definitely be towards the top of that list A good intake and full exhaust system are always a plus as well.

 

[Jonathanlc05]

thanks everyone. infact i was showing the engine to my friend, ill post pics later but i believe there is an ignition system in there too

 

[XMasta19]

Well you better hurry up and post some pics...we're curious

 

[Jonathanlc05]

ill post pics later tonite, but how reliable would these be if i put a turbo kit in it

 

[GSGoinFast]

Ill chime in about the CAI and exhaust. That difference is noticable and the two mods in junction will alter your horepower and torque curve noticeably. I observed this after my V2 and exhaust were put on:
At 80 mph, the totaly stock 420a eclipse will have an engine speed of 4000rpm. With the CAI and exhaust (2.5" + stock cat) instaled, the car now has an engine speed of 3500 to 3400rpm at 80mph.
This shows the horse power curve was shifted to the left, but it was also lengthend because of the noticable pull up into the higher rpm's (7000 ~ 7200redline). More torque is noticable but their is a loss in the lower rpm range. (around 1000 ~ 3000rpm).

Actually that doesn't show a power curve shift, that shows you didn't really pay attention to the rpm to speed ratio of your 5th gear before you put those parts on. Last I checked, CAI and exhaust don't change your gear ratio

infact i was showing the engine to my friend, ill post pics later but i believe there is an ignition system in there too

I'd sure hope so, otherwise that car won't run

ill post pics later tonite, but how reliable would these be if i put a turbo kit in it

Well it depends on your driving habits and if you beat on the car or not with the turbo. I have had my turbo kit on for about 15k miles now and my car has never stranded me because of it(it has for other reasons but I won't get into that now)

 

[XMasta19]

yeah, same here.....damn egr

 

[Jonathanlc05]

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[Jonathanlc05]

just did it now. sorry i worked till 9:30. its all there and might be alittle hard to see with the flash on this camera phone. infact all of these pics are camera phone. last time i checked the idle, i think it was 6 or 7 hundred but could have been that because i had the fans going.

 

[VelocitàPaola]

Chris, I thought that was your car when I saw the interior!

*****************

700 RPM is a decent idle. Everything looks good.

 

[Jonathanlc05]

i forgot to write something but the funny thing was i pulled out so hard, my sirius popped off the windshield

 

[WMD]

Actually that doesn't show a power curve shift, that shows you didn't really pay attention to the rpm to speed ratio of your 5th gear before you put those parts on. Last I checked, CAI and exhaust don't change your gear ratio

Actually I did, I know my car better than you do. dont be a smart ass.

Here is a dyno chart from AEM
http://www.aempower.com/pdf/dyno/24-6030 98 Eclipse 2.0 V2.pdf
Notice the curve change in the exact area I was dissicusing? Notice the dip in the stock dyno run at 3750? Now notice the dip at 3500 on the V2 run. Why does the SAME dip occure on both charts but at different places? The gear ratios didnt change but the curve shifted in that spot, why? how? whats going on. I guess I was right.

Why did the apex of the curve shift left?
http://www.aempower.com/pdf/dyno/24-6016 98-02 Honda Accord EX.pdf
Why is the stock bump at 4500 now at 4100? and also the bump at 5700 to 5500.
http://www.aempower.com/pdf/dyno/24-6015 98- 02 Accord 4cyl.pdf
Why did the apex of the curve shift to the left?
http://www.aempower.com/pdf/dyno/24-6005 97-01 Prelude DOHC VTEC.pdf

Heres the original cold air setup
Why did the point at 6400 shift to 6200? and the point at 5800 to 5700.
http://www.aempower.com/pdf/dyno/21-640 2006 Mazda MX-5.pdf
Why did the point at 5500 shift to 5200?
http://www.aempower.com/pdf/dyno/21-493 2000 VW Golf 1.8L Turbo CAS.pdf

But I must admit, I did make a generazation, it is more slight than I had imagend. But it can and does happen, I just proved it with dyno results.

 

[GSGoinFast]

But I must admit, I did make a generazation, it is more slight than I had imagend. But it can and does happen, I just proved it with dyno results.

Actually you just proved you don't understand the difference between horsepower and vehicle speed. Look at the left variable on every one of those dyno charts. Do those say Vehicle speed? Is the measured unit MPH? No. Its not. It's measuring power. Did I say your power wouldn't go up from a CAI and exhaust? No, I didn't, because it will marginally. What you claimed was your RPM at a certain speed was lower after CAI and exhaust then what it was before them. That is completely false, the only way to change your RPM at a certain speed in a certain gear is to change the gear ratio.

I guess I was right.

No, you weren't, and I suggest you figure that out before making yourself look more foolish.