Not pushing as fast after mods!

[kilmore]

I picked up my car last week from the shop after putting in some new mods and last night I actually had the chance to push it since I was the only one on the highway.

My DSM can no longer push as fast as before.

Before the mods I added, I was able to go faster and this was only with a generic exhaust system + headers, and a short ram intake.

My DSM went to the shop for stage 2 cam shafts + gears, aftermarket intake manifold, 57mm throttle body, and the lighter underdrive crank pulley. This makes me sad and I hope to rectify this problem no later then next week.

 

[GsXdSmKingGsX]

Thats just God telling you, you dont need to go that fast

And your sure thats all the shop messed with?

 

[kilmore]

One would hope no mechanic messes with ANYONE's car. Two of my other friends recommended I get my work done there and they also drive DSMs. I don't think they would, they were good people.

 

[GsXdSmKingGsX]

I've had the same thing happen to me. Not saying they did this but the shop broke more things than they repaired in the hope that I would keep coming back. And man they got one hell of a law suit.

 

[GTOJohnny67]

I this kind of thing happens all the time with naturally aspirated motors. The wrong combo of parts will definitely slow you down. Also if you went with a higher gear ratio you'll definitely loose top end speed. You've moved your power curve down to get more torque, you will now come off the line harder but sacrifice top end speed.

 

[BLINKY619]

maybe ## spedo went... idk... maybe

 

[Colt4G63 also]

The engine has to work harder to cope with the crankshaft shattering vibrations that you introduced by removing your harmonic balancer.

I see poor results quite often when non-mecanically inclined people who don't work on their own cars chose an upgrade path on their own.

 

[GsXdSmKingGsX]

The engine has to work harder to cope with the crankshaft shattering vibrations that you introduced by removing your harmonic balancer.

I see poor results quite often when non-mecanically inclined people who don't work on their own cars chose an upgrade path on their own.

Actually, according to the Tech articles on upgrading the 420a, he is right where he should be.

 

[kilmore]

What do you recommend? Should I put my stock cams back in?

What should I take out and what should I leave in? I can't have this.

 

[GsXdSmKingGsX]

What do you recommend? Should I put my stock cams back in?

What should I take out and what should I leave in? I can't have this.

What cams did you use?

 

[kilmore]

I have obx cams

 

[master jared]

just get fuel upgrades

 

[RadDsm]

There is no need for you to go that fast anyways.

You can't trap over 99mph in the 1/4 and you shouldn't be going that fast on the highway.

 

[GsXdSmKingGsX]

Well the cams is whats slowing you down but just add a fuel pump and all those goodies. Im sure you dont want to pay to have a mod taken back out. Just build around your current set up.

 

[92AWDHX40]

Do that at at the track not on the road, this thread needs to be closed for that reason only there are innocent people on the road.

 

[black cotton]

All of excluding the UDP are modifiactions aimed at adding more air at a higher power band. The cam shafts are designed to perform well from 2k-redline, the cam gears are cool for looks, however did they set them to any type of time? Or are they set to factory timing specs aka 0-0, any adjustment to cam timing can drastically reduce bottom or top end.

As for a larger intake manifold and throttle body, most expereiences I have had with the 420a platform is that the stock manifold is the most efficient and effective, for both torque, and air velocity, being that you did not upgrade to forced induction, I can easily see all those modifications drastically reducing both low and high end, and only helping you in the mid range. I am willing to bet your HP and TQ curves are both extreemly flat at this point.

What cam gears and what intake manifold did you go with? OBX cam gears are known for providing false timing even when set at 0-0, also the OBX intake manifold is an extremely poor design, in some cases I have seen the runner ports dont even line up with the intake ports on the head, which will cause all kinds of problems.

I hope you get this resolved!

 

[GsXdSmKingGsX]

He wasnt promoting street racing and dont even try telling me youve never stretched your cars legs on the highway. He has a valid question how about you help him instead of complaining.

 

[92AWDHX40]

Hey ill leave it alone, was it on the road, i was almost killed by someone traveling a high rate of speed, with my neice and newphew recently thats why i questioned the speed. Not to start a argument i was just saying.

 

[snowborder714]

The only time we allow high speed talk is coming from a track/street experience. Yes, we know people do it on the highway, but we don't condone speeding on public roads as it is illegal and dangerous. It's best to leave out speeds and just focus on the issue - after installing mods, my speed has seemed to decrease.

Edited original post to reflect this and moved to appropriate forum.

 

[92AWDHX40]

That sounds a lot better Brian. Now we can get back to his mods maybe he should have left the dsm as is.

 

[91stocker]

Now im not familiar with the 420a's but wouldnt a cam upgrade need some sort of tuning or support? I see you didnt mention anything to tune with. Full bolt on with cams seems like you would be maxing that tiny fuel stock fuel system. Just a thought though, i have no experience with the 420a.

 

[Fotowntalon]

Please ignore a good 75-90% of the reply's to this thread, because contrary to popular belief not all 4g63 knowledge applies to the 420a motor....
First off, the OBX is an upgrade to the stock IM, if you made sure it was quality and fixed the imperfections see 2GNT.com - OBX_Intake_Install
As for the best IM upgrade, see the AMM IM ( i think i said something about this before to you)
The UDP, or lightweight crank puller whatever you want to call it is not an issue with the 420a motor.
Also you dont need to upgrade your fuel system till you start to get close to the 200whp mark, which you are not.
For the OBX camshaft information, I am not sure about that, but it wouldn't surprise me, OBX is crap for the most part when it comes to quality control. for your cam gears, are they zeroed out? Were the messed with? If they were adjusted were they done by the mechanic or via dyno tuning? From my experience camshafts don't add much if any pull till 4k+ and for the cam gears even with all my mods i only gained 2whp from dyno tuning the gears in.
How long have you had these modifications? Our ECU learns and adjusts over time to try and become efficient (only to a certain extent) it may just need some time to adjust, also our ECU is pretty much crap, upgrading to MSnS or AFX ECU with your mods should net great gains, one problem you may be noticing is with all the mods your A/F ratio is simply off.
Lastly, (this may have been edited out earlier) how do you know you aren't pulling as hard? No offense but the but dyno isn't very accurate. Best way to tell is via dyno/track time comparisons.

Hope all this helps some

 

[VelocitàPaola]

The engine has to work harder to cope with the crankshaft shattering vibrations that you introduced by removing your harmonic balancer.

The 420A doesn't have a harmonic balancer... just a pulley.

 

[VelocitàPaola]

Before the mods I added, I was able to go faster and this was only with a generic exhaust system + headers, and a short ram intake.

My DSM went to the shop for stage 2 cam shafts + gears, aftermarket intake manifold, 57mm throttle body, and the lighter underdrive crank pulley. This makes me sad and I hope to rectify this problem no later then next week.

There's a mixture of good and bad information floating around here...

Here's a summary of the good information:

• You added a lot of parts that generally require some tuning before you see any gains. For this, you need a programmable ECU like a MegaSquirt EMS.
• You added a few parts that aren't very useful unless you're already making an appreciable amount of power.
• The combination of parts wasn't well thought out.

If it were my car, I'd remove everything you just added except for the UDP. Cams and bigger throttle bodies and intake manifolds are meant to allow for a greater volume of air to flow through the engine at the expense of velocity. You don't have anything like a turbocharger to force more air in; instead you're just stuck with reduced velocity.

I know how it is to be excited about new parts, but the stock equivalents of what you just replaced are more than adequate for your car.

 

[dsm8883]

OBX cam gears have been known to be marked wrong. I have a set that the exh cam gear was wrong.