My first 4v...I got???

NoMercy · Mar 2, 2014

Hello everyone, just sold my pushrod sn95 hci car and bought a 97 cobra vert it's mostly stock with a procharger and exhaust. Plz bear with me I'm a 4v virgin. What's with this cooling mod I keep hearing about? Should I def do the mod and from what I read not sure but is there more than one to do the cooling mod? Next question do these cars have a hydraulic or cable operated clutch and is there any adjustment with the stock pieces? My clutch doesn't grab until the pedal is well off the floor...not sure if it is just worn or need adjustment? My final question at the moment any ways is the car will no rev past 5k rpm it's all most like it's hitting a rev limiter but it really smooth? Is the procharger blowing out the spark? What spark plugs and gap do you run with a blower car?and is there any other quirks about these cars I should know about or look for. Sorry for all the ? I just got the car yesterday

the.greg · Mar 2, 2014

If its a stock clutch quadrant, its self adjusting by pulling the clutch peddle back towards the drivers seat. And its a non-assisted clutch, not hydraulic.

Is the car tuned? Its possible the tune altered the redline, but otherwise a 4v shouldn't stop at 5k.

As far as the plugs go, I recommend NGK TR6 plugs, I was at 9psi and I gapped them at .032 -if you are mostly stock this should be a fine gap, but with very high boost you could gap even tighter. Idk about blowout, but these plugs are one step colder than stock and great for boost^

NoMercy · Mar 2, 2014

I'm assuming they procharger kit came with some kind of chip with a different tune than stock? Do you use the stock coils?

the.greg · Mar 2, 2014

You need to confirm the chip/tune. Its not worth blowing an "expensive" 4v engine because of a crappy tune, many reputable companies can even do mail order tunes, especially considering you are a simple combination of mods. I know a tune may seem like a big expense on top of the cost of the vehicle, but especially if you bought it modded, you need to make sure its running properly. I bought my old car in my sig pre-modded, and my tune was way off, not only are you leaving out horsepower, but driveability and engine safety. Gotta check that afr and confirm its good to go!

Yes, stock coils are not at all a limiting factor at your power levels.

Do you know if your fuel system has been upgraded for the blower demands? What psi is the procharger making? Some bigger injectors/maf/fuel pump should be looked into and tuned for. You may be fine at lower power levels, but these would be the next things to consider imo.

NoMercy · Mar 3, 2014

I got all the paper work with the car and it looks like some bought the procharger new and i think it came with a external booster stye fuel pump. I saw it under the car to when I was looking to buy it. It has 30lbs inj in it... Seems kinda small huh? Not sure bout the maf. I just got it and it's been raining and bout to snow a foot here

SMOKEDYA · Mar 4, 2014

The cooling mod is running a coolant hose from the back of the heads and connecting them. The reason is the 4v on the driverside the back 2 cylinders get hot due to lack of cooling. Heres a link
http://www.lethalperformance.com/mmr-5-0l-ti-vct-head-cooling-mod.html But it could be made for way less! If your use to push rods,then yes the injectors on 4v do seem small. If a mach1's MAF will work for you and be an upgrade? I have one for sale complete calibrated to stock injectors.

96blak54 · Mar 4, 2014

The tune is an absolute must with force induction. Be 100% sure what the tune is before running the car or youll be ruining the car! Any detonation will break the piston ring lands...period!

This is what i would do if I aquired the same car. Pull into a dedicated garage with the intent to remove the upper intake for a good cleaning. The heads are a B series style and has 2 seperate intake ports. The injector fires into the main port but not the second. With no gas spray this causes the second port to gum, carbon up. Also the second port has a butterfly valve that activates around 3000ish rpm's opening a path for more air into the cylinder. With the port gummed up, the butterfly is also gummed up and will keep it from opening. 60,000miles is about when the ports needed to be cleaned.

NoMercy · Mar 4, 2014

Dam i would hate to have to take it apart as soon as I got the thing and I built my pushrod motor so I'm sure I can do it that would just suck. The cars only got 44k miles on it but it could be gumed up from not being driven much to I guess. Is there any way to externally check the butterflies are working? Are they vacum operated or electric? I def going to have to verify the tune. The drivability of it was amazing compared to my 94 hci car tho and the one time I tried to get on it cut out a 5k rpm. It didn't detonate it was different than anything I have experienced before so I was just guessing it was something related to boost as I've always had n/a cars. I'm assuming the ecu is in the pass kick panel like my 94? Do I need to buy some kind of tuning device before I go to get a tune?

96blak54 · Mar 5, 2014

Im thinking you need to take the supercharger off and run it n/a to see how she runs. If all is good then rebelt the charger. A lot can be wrong but before you move on, be sure the car is running its best n/a. The stock engine should rev easily to 7000rpm smoothly. So while your under the hood look toward the back of the intake close to the heads entry you will see a throttle like situation. Engine off, rotate them to see if they freely turn. Then engine on, rev engine pass 4000rpm rotating the main throttle and watch the secondary throttles to see if they operate....both of them. These throttle plates are call intake motion runner control plates or IMRC

MAF sensor could be dirty. Especially if there is a kn filter or other type of oil saturated junk filter. Oil gets on the sensor and this speeds up getting dirty.