DO NOT Buy Bosch Platinum +4 for Vipers!

[Viper Specialty]

Just wanted to make it a publicly known fact...

I replaced my stock plugs with +4's (4428) while doing my B&B Cat-Back and RT High Flow Metal Substrates. After install, I took the car for a ride, and it felt sluggish, especially on the bottom end, even compared to stock...as well, the exhaust popped a LOT, and loud ones too. At first, I figured that it was the B&B/cat's fault, and got quite **********. Out of curiosity, I pulled one of the +4's out to read the plug. The plug looked fine, but on a hunch, I compared it to one of the stockers... the +4's firing area is almost 1/2 inch shorter than the stocker's! (1/2 inch FARTHER away from center of Combustion chamber)

I picked up 10 new stock plugs, installed, and WOW, WHAT A DIFFERENCE. Tires now light up from a first gear roll without a hitch. Then I took the Viper in for an alignment/inspection/oil change and had the V. Tech reflash the PCM while I was there. Felt about the same as after the plug swap back to stock, then after 2 or 3 cycles, picked up even MORE go-juice.

I know with a base of 450 HP, even 25 is hard to notice, but you CAN notice the difference with a B&B and HF Cats, at least on my car. I have not dyno'd it, but I suspect it was a pretty hefty increase to be able to notice this easily.

PS- B&B is the way to go! VERY LOUD durring accel, but virtually no drone in 5/6.

 

[Viper Specialty]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

PS- the Bosch plugs come with a gaurantee. If you dont feel improvement, send them back, and they give you a refund. I sent them back today. I must say, due to that type of customer satisfaction, I would not hesitate to purchase another Bosch product.

 

[CoryMac]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Bosch windshield wipers kick a$$!

 

[Chuck 98 RT/10]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Bosch windshield wipers kick a$$!

LOL They say you can't notice the hp gain but I noticed something. LOL

 

[Joel]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Had a similar problem with Denso Iridium plugs a while back. Changed back to the standard and problem gone.

 

[joe117]

"the +4's firing area is almost 1/2 inch shorter than the stocker's! (1/2 inch FARTHER away from center of Combustion chamber)"

I think this would be typical of a colder plug. The colder plugs don't stick out so much and the center insulator contacts the metal part of the plug closer to the tip. A colder plug just takes heat away faster.

What do you mean, "2 or 3 cycles"?

 

[jimandela]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

great info FinalGTS!

I wonder if the Bosch 2 are short as well?

Thanks
Jim

 

[RedGTS]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Can't say how they work on a stock car, but they seem to work well with a blower.

 

[Sean Roe]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Hi Dan,
With all due respect, I just measured the distance to the center of the spark area on both plugs. From the mounting surface of the head, the Bosch + 4 is exactly 0.115" shorter than a stock Champion plug, not 0.500".
We just had a local 2001 RT/10 on the dyno do 422 RWHP with tubes, filter, muffler delete, VEC1 and the Bosch +4 plugs. The owner was pleasantly surprised that he could feel the improvement the plugs made. Reference: http://www.floridavipers.com/forum/topic.asp?TOPIC_ID=203
The Platinum plugs require less arc over voltage to start and can bridge a wider gap, exposing more of the air/fuel mixture to spark.
I believe you must have either had a bad plug or something else was going on (PCM relearning after the exhaust install?).

Regards,
Sean

 

[ViperJoe]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

"Drive cycles"

Usually a start up, a full warm-up and drive up to a minimum terminal speed, and shut down.
If you are interested here is the info on GM "drive cycle" for OBDII:

A cold start is a necessary step in preparation to run a complete OBD-II compliant drive cycle.
If a car is driven under the correct conditions, all of the OBD-II monitors will run their various tests, and if a test fails, sets a "pending" or hard code (MIL is illuminated).
Differences in how each monitor runs a test define the type of TRIP needed to run that monitor.
Some monitors are run only on cold engine startup, some only on a highway cruise speed with the TCC off and others at idle speed with A/C off.
Some tests will not run until a car is driven in a drive pattern that meets all of its enable criteria.

Valid Drive cycle table Requirements (total time - 12 minutes)
 Cold startup ( coolant temperature less then 122 degrees)
 Idle 2.5 minutes in "D" or "N". A/C & defogger "off"
 A/C "off", accelerate to 55 MPH at 1/2 throttle
 Steady state Cruise at 55 MPH for 3 minutes
 M/T clutch engaged, no braking, Decel to 20 MPH
 Accelerate to 55-60 MPH at 3/4 throttle
 Steady state Cruise at 55-60 MPH for 5 minutes
 Decelerate without braking


Detail:
A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in less than fifteen minutes.

To perform an OBDII Driving cycle, do the following:

Cold Start In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.

Idle The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.

Accelerate Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

Hold Steady Speed Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.

Decelerate Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

Accelerate Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.

Hold Steady Speed Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.

Decelerate This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

End of valid drive cycle
Note: Specific engine warm-up conditions must be met in order to complete all OBD-II tests.

Engine running, ECT input increases 40 degrees AFTER engine startup has reached 160 degrees.

Keep in mind that there also is a re-learn process that needs to be done for correct idle.
In most cases for a MN6 based C5 you would:
 Cold start and idle for 5 minutes ( all power functions are off)
 Turn on A/C only and continue to idle for another 5 minutes
 Turn A/C off, continue to idle for 5 minutes

 

[Viper Specialty]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

SEAN- some more info:

It couldnt have been a bad plug, as I tested each plug individually before install AND After Removal. They all did arc the same. As well, by "reading" the plugs, all cylinders were firing.

It also couldnt have been the PCM, as I had it reflashed both times, (and gave it time to learn both times) and there was a substancial difference.

All I know is that the +4's have 4 strikes against them in my book:

1. It felt sluggish to ME after install, gone immediatly after the swap back to stock.

2. 2 Passengers (same ones) confirmed the EXACT same experience as I did

3. With the +4's, the car bucked, popped, and even backfired somewhat upon deaccelleration (sign of incomplete combustion), which was virtually gone after switch back to stock.

4. The +4's had (and do still have) the exact same problems as I have outlined in other cars, particularly the 3000GT VR-4 Twin Turbo. Though the issue on that car is somewhat different than mine- (Spark blowout due to an exposed spark kernal coupled with higher levels of F.I.)

PS- I will be picking up (1) of the +4's today, and measuring it for myself. Its not that I dont trust you, but I could SWEAR it was WAY more than .115. So, either I'm going nuts -(which is perfectly possible)- or something else is going on here with these plug...

 

[V10 MOJO]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

I always put champions in mine and i change them often. a couple weeks ago i decided upon a whim when out buying oil to also pick up a set of +4's. i put them in and the car is doing excellent. maybe better than or just as good as champions. the only reason i probably wont try them again is d/t cost (and durability). since im not "positive" my car is truly performing better i might as well stick with champions. definitely no experience like yours though, thankfully.

 

[Joel]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Dan, same experience on the first 3 points with the Iridiums, seemed to be smooth at first but over a distance of about 500 miles got progressively worse, 1/4 mile times that weekend were slower. Put the old champions in and things returned to normal. Put it down to std motor needing the spark well projected into the chamber. Motors running none std fuelling may be totally different

 

[Viper Specialty]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

JOEL- that makes sense... as the iridiums arent long reach like the stockers. In the case of 3000GT's, the Iridiums are a God Send, but then again the 3000GT's dont use a long reach plug like a Viper does.

I have the feeling the A/F ratio has a HUGE impact on how the plugs will make the car run, especially since the SC cars like them. In the case of my car, with the +4's, idle was OK, and TOP end of the RMP spectum was OK, but low end, 1K-4.5K or so SUCKED. The VEC2 changes the A/F ratio at certai RPM's, and the result may be positive with the +2's, and maybe even the +4's.

 

[Viper Specialty]

well, conclusion is I am going nuts... lol. the difference between the plug firing area's is a little over 1/8 inch. I have attached a picture however to show how substancial it really is though:

 

[joe117]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Sean,
I looked at the Florida Viper site and read the report on the +4 plugs. I never heard of special plugs making a SOTP difference compared to new stock plugs in a stock engine. I'm not arguing with you but I'd like to hear what you think is going on here.
How much extra power would you say the plugs are giving for the SOTP feel?
Why are they giving a power increase?
Why are some of the guys saying that the +4 plugs give them poor performance?
What's going on with the discrepancy in Lesser's measurements of the plug length and your measurements? Are you both talking about the same stock number plug?

 

[ViperJoe]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Asked this on another thread, but since this one deals with plugs.... Anyone know why Dodge went with such a low tec plug for the Viper? Not even copper let alone platinum!!

 

[Sean Roe]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Hi Joe,

You asked:
"I looked at the Florida Viper site and read the report on the +4 plugs. I never heard of special plugs making a SOTP difference compared to new stock plugs in a stock engine. I'm not arguing with you but I'd like to hear what you think is going on here."

Jon said he felt the new plugs ran smoother. I'm sure the fact that he replaced used plugs helped make the SOTP difference. It wasn't something I had anything to do with (changing them) and I'm sure he would answer an e-mail if you asked him about them.

"How much extra power would you say the plugs are giving for the SOTP feel?"

I don't know, but will test them on the dyno. The reason I like them is because my car starts faster and runs smoother with them versus standard plugs.

"Why are they giving a power increase?"

If they are giving a power increase, one reason may be their wider gap, exposing more of the air/fuel mixture to the spark.

"Why are some of the guys saying that the +4 plugs give them poor performance?"

I don't know. All I can tell you is of my experience.

"What's going on with the discrepancy in Lesser's measurements of the plug length and your measurements? Are you both talking about the same stock number plug?"

Yes, we're talking about the same plug. I measured it with a micrometer three times and got 0.115" from the crush washer to the center of the spark area each time. Dan got about 1/8" (0.125"). So, I'm not sure where the other 0.010" is at, but it's not enough to change much.

Regards,
Sean

 

[jimandela]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

darn it if i could change my own plugs i would give the bosch +2 a shot
but i can barely, paint a hood pad.
maybe if Dan gives me a hand, i might try the bosch 2 and report back..

dan, free weds or thurs?

now i am curious.

by the way, the VEC1 kicks bass Sean! what a product!

 

[GTS Bruce]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Why a cheap plug?Ans:They work just fine and we are anal and throw them away,replace with new at far less then their usable life span. Bruce

 

[jimandela]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Bruce,
great point!
if we have time this year we need to get together.
I want to hear your beast!!!

 

[1TONY1]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

I installed my 4's tonight......so far I can't tell any difference between them and the short reach Champions. I also checked with the micrometer and got .115 difference. I think because the metal is taller/longer on the Bosch it makes the electrode look alot shorter than it really is.
Still breaking up/missing bad around 4000 with the a/c on. I have gotten 8 injector plugs, the others are on backorder...maybe that will help.

 

[Larry Macedo]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Tony,

Regarding your break up around 4,000 rpm's, do you know if the timing cover or timing cover gasket has been replaced or if the A/C compressor has been replaced? With the hood open and looking straight down at the A/C compressor, you'll see the top compressor bolt closest to the exhaust manifold has a ground wire attached to it. You may want to check that ground connection for grins.

 

[1TONY1]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Thanks Larry, It had an Arrow rebuild about 25k ago and I replaced the a/c compressor early last summer. I know that I would never forget.......... nevermind I will check the ground. Good idea.

 

[Larry Macedo]

Re: DO NOT Buy Bosh Platinum +4 for Vipers!

Tony,

If the motor has been out, you may want to check the main ground strap at both ends. At the passenger side frame rail and also at the backside of the tensioner on the timing cover.