VTEC Does not scream as hard as it should

[Fry]

I have a 93 CRX/del sol (B16A) DOHC VTEC and notice that when VTEC engages it doesn't scream as hard as the CIVIC VTIR (B16A engine as well)..

My brothers mate is a mechanic and took my car for a spin, he said vtec is not poping as hard as it should, and that I needed to change something to do so... My current mods are - extractors, exhaust 2" piping, HKS air filter and Ceramic coated air intake pipe, Power chip gold. I don't know what to change, any suggestions or has anyone had the same problem?

Also I wanted to get 2.25 inch cat back piping but they said that I would lose power, but I've seen & read about alot of crx, civics and integras with 2.25 & 2.5" piping.. What would you guys recommend?

[genesis]

put ur stock air box back on, and reset ur ECU

[Fry]

so do I just take of the connections to the battery for 10 mins?
after 10 mins do I just reconnect everything and start the car? Thanks

[LatinoHatchCrap]

VTEC is engaged through several factors:
1. Engine oil level should be right (4-5 quarts)
2. Engine temperature should be normal (temp gauge at mid level)
3. Check your wiring loom and make sure that VTEC solenoid is working correctly

strat by checking these three things; dont let anyone tell you its your mods 'cose thats bullshit VTEC is an inbuilt mechanism which is not affecte by bolt ons like headers and intake good luck

[Fry]

Thanks Fellaz I'll give it a try, what is the VTEC solenoid? may be thats the problem...

Just wondering what piping you guys would recomend?

[LatinoHatchCrap]

VTEC solenoid is just a electrical cable between the ECU and engine,,,check the connections
And another word of advice: go to repco or bursons and buy yourself a chiltons manual for your car for 30 odd dollars...best purchase for your car you'll ever make :) it'll show you how to actually find it and connect/disconnect
btw the only way you can truly diagnose whether vetc is working or not is on a dyno,,,different VTEC engines have different switch points so dont pay too much attention to someone who just says they cant hear it/feel it,,,gl

[Fry]

Thanks. I actually just found out what it was. Had a look in google, this guy attached an LED to the Vtec solenoid wire and put it on his dash so when vtec engages the led lights up as well.. looked pretty good, might try it.

[Civic Si]

An 2" exhaust is fine or u'll lose more low end torque if u go ne bigger.

[vti-2]

Originally posted by Civic Si:
An 2" exhaust is fine or u'll lose more low end torque if u go ne bigger.

The bigger the exhaust the more top end you will get. This means that you will lose bottom-mid power in order to get that top end. For N/A usually 2.25" is best as you will get best of both worlds. A 2.5" exhaust will be louder and will give you more top end but you will loose responsivenes down bottom. Anything bigger than that is useless and you will actually loose heaps of power. VTEC's need the right back-pressure, if the exhaust isn't setup correctly, even a 2" system, you will be loosing power.

[one more chance]

I have a 93 CRX/del sol (B16A) DOHC VTEC and notice that when VTEC engages it doesn't scream as hard as the CIVIC VTIR (B16A engine as well)..

My brothers mate is a mechanic and took my car for a spin, he said vtec is not poping as hard as it should, and that I needed to change something to do so... My current mods are - extractors, exhaust 2" piping, HKS air filter and Ceramic coated air intake pipe, Power chip gold. I don't know what to change, any suggestions or has anyone had the same problem?

Also I wanted to get 2.25 inch cat back piping but they said that I would lose power, but I've seen & read about alot of crx, civics and integras with 2.25 & 2.5" piping.. What would you guys recommend?


ur mechanic friend of yours......what car is he using to make comparisons....?? from the mods u have mentioned, u should be going forwards in performance, instead of backwards. i hope he isnt' using something like an ITR as a reference....

[Jnr Teggy]

return it to standard....give it a full service...then dyno it...

get a K&N drop in filter, 2 1/4" exhaust (cat back), reset the ecu then dyno again..

vtec hondas come perfect from the factory FYI...so most backyard hack mods will result in a loss of power..

cheers

sam

[[G]]

what extractors are you rrunning...dont waste your money with cheap aussie headers..Just save up and get something decent from Japan or the US. Theres quite a few second hand jap spec headers going around for reasonable prices..

[Weq]

U cant really feel where my vtec hits (SOHC d16) but f*ck, u can EASILY see it on a dyno. I say if u think u have got problems, invest in a $~60 dyno run and get some numbers down as a base. Then go from there..

[Setanta]

With my B16A you don't feel any great kick other than the steering wheel kick (yep - torque steer even with equal length driveshafts - but not too bad). I wonder if your mechanic friend actually knows much about Hondas ;) The point of VTEC is to maintain a linear torque curve while producing reasonable bottom end followed by strong top end. It's NOT a turbo if he was looking for that effect :P

[wynode]

(yep - torque steer even with equal length driveshafts - but not too bad).

Really?

[VTi-RT]

I would also like for you to explain "equal length drive shafts" Setanta....

[Setanta]

From the EE8 (European EF8 SiR - same design as the EF9) VTEC supplement. The EE8 and EE9 were simply JDM dies in LHD and RHD configuration that were built in Europe. The only difference is that their B16As only produced 150bhp and they ran slightly different interior trim. The description is spot on for my EF9:

"An Intermediate shaft is used between the differential unit and the left-hand driveshaft to allow right- and left-hand driveshafts of the same length. Since the left end of the intermediate shaft is at the same level as the differential unit, the joint angles of the right and left wheels are the same and noise and vibration are reduced as well as less torque steer is generated."

Even so, on VTEC activation under WOT the front wheels do pull to one side. Often it has to do with the road as well, but the car while nowhere near as much of a handful as others I've owned, does bump around.

The SiR was the first gen of VTEC built cars (along with the XSi) and there isn't too much that is as refined as an EK VTiR.

Hope this helps :)

Cheers

[stockie]

also make sure that your power chip gold hasnt lost it settings..
Remember its only a piggy-back ecu system.. So when you disconnect your battery, it may have lost it setting..

Just my 2 cents.. :D

[BMTDC2]

I wonder if your power chip has got anything to do with it...

Has your car been dyno tuned or just chipped and hoped for the best?

[Fry]

Sorry guys the car runs well, chopped a couple of commodores (V6's not V8's), its just the sound when VTEC kicks in, its not as loud as my friends civic vtir..

[Fry]

How do i check the settings of the power chip?
what does the VTEC solenoid do? and can it be changed?

[Fry]

When I got the car it already had the chip in it, don't know if it was dyno tuned - how much would it cost to dyno tune my car?

[A'PEXi]

really depends on the company. chiptorque here do it for $150 per hour

[AP1 F20c]

If you've increased power with the mods listed, what you've done is "smoothen" the VTEC transition across the entire powerband. Instead of feeling the "kick", you gain more power by having the powerband smooth out.

Wynode edit: Black text only thanks

[Fry]

Anyone know where the ecu is located and how to check if there are any errors? are vtec solenoids all the same?

[AP1 F20c]

Your ECU is usually located on the passengers' side near the kickplate, it's the panel identical to where your - Hood pop is located on the drivers' side. The VTEC solenoid is more like a switch, if you have VTEC, it's working and if it doesn't activate VTEC it's not working. Chances of that failing is pretty rare. That's all the VTEC solenoid does, nothing more and nothing less.

[FANATK]

with the sound it could be the diff air filters or standard air boxes however your set ups are, most of the sound comes from there... try swapping each others setup and see what happens... or various other mods if not the same could cause this...