Questions: T-stat, plugs, UD pullies...

[Shaft333]

I have a couple of questions for some of you...
I've been reading many of the threads found a few mentions of some things that I'm curious about.

Particularly certain mods that come up. Often as reccomendations for new MM owners.

Why the colder thermostat and spark plugs? What's the expected gain? What's the actual gain? What are the potential issues?

What about the underdrive pullies? I know the theory behind them, but how effective are they? What's the drawbacks to them?

What's the dollar to performance ratio of these mods?

[Smokie]

There is disagreement about the cooler stat and plugs, without tuning they are a waste of money, with tuning the served me very well. I will provide you with a link you may find helpful, if you search threads started by me there is far more, I have documented a lot of small mods. Good luck.

Information:CLICK (http://www.mercurymarauder.net/forums/showthread.php?t=13390)

[BADMERC]

Underdrives are about the best bang for the buck. You sure can feel the difference. Dennis runs the colder T-Stat, Where Lidio does not. Change the pulleys and the gears. You will love it.

[Blackened300a]

Like Was Said, without Tuning, The Plugs and the Stat are useless. However, the UD Pulleys were my very first mod and they made a nice improvment! More Power off the line and then engine seems to rev a lot more freely. However on the Down Side, I noticed that my voltage was a bit lower with the pulleys installed. But I never had a problem starting or anything like that, So the pulleys are worth it IMO There are many posts on the installation of them on this board

[RF Overlord]

Why the colder thermostat and spark plugs? What's the expected gain? What's the actual gain? What are the potential issues?Shaft, the cooler plugs and thermostat are generally only used when a chip or tuner is used, and then only when recommended by the chip or tune supplier. Using them indiscriminately can cause plug fouling, and/or reduced fuel economy. When they ARE recommended, it's to reduce the chance of pre-ignition caused by the more aggressive spark and fuel tables the chip/tune uses.
What about the underdrive pullies? I know the theory behind them, but how effective are they? What's the drawbacks to them?Underdrive pulleys do save a few HP; it's been reported they're good for 4-7 HP, but more importantly they allow the motor to spool up quicker, resulting in improved throttle response and a perceived SOTP improvement. The only real drawback is when idling in gear at a stoplight (for example) with a lot of accessories turned on (A/C, big-ass stereo, high-beams on, foot on the brake, etc) your charging voltage can drop, resulting in a slight dimming of the headlights and, since the A/C compressor is being driven more slowly, you can get a reduction of the air conditioning output. This can be solved very easily by having your chip or tune modified to raise the idle speed in drive 100 rpm or so.

[fastblackmerc]

There is disagreement about the cooler stat and plugs, without tuning they are a waste of money, with tuning the served me very well. I will provide you with a link you may find helpful, if you search threads started by me there is far more, I have documented a lot of small mods. Good luck.

Information:CLICK (http://www.mercurymarauder.net/forums/showthread.php?t=13390)
What Smokie said on the plugs. The underdrives eliminate some of the parasitic drag on the engine.

[Rider90]

Plugs and T-Stat are worth 10 HP alone, where is that Type R sticker? Make it 15 - TO THE WHEELS!!!!!

[MarauderMark]

Plugs and T-Stat are worth 10 HP alone, where is that Type R sticker? Make it 15 - TO THE WHEELS!!!!!

So with the combo he's looking at 17 to 20 more rwhp?

Here it is that R sticker. :D
http://www.mercurymarauder.net/forums/attachment.php?attachmentid=66 52

[Rider90]

...That R sticker is real? oh my...... :eek:

[MarauderMark]

...That R sticker is real? oh my...... :eek:


Yeah but on my car it doesn't mean rice :lol: . It's R for Reinhart.That R got me over 426 rwhp :D

[Shaft333]

So would it be possible to say (given the marginal HP improvement) that the UD pullies move the torque curve over a bit to allow for more of that SOTP feeling? Or is 5 to 7 hp that easy to realize while behind the wheel?

I'm still a bit unclear of the stat and plugs. Is it those items that are somehow improving hp, or is it that they allow for a more aggressive tune that gets the power?

<---- I'm just trying to increase my motor knowledge. I often read about such things in the rice forums, and I attributed them to just wanting to spend more dough... when you guys start talking about them, I'm thinking there might be a tad more to it.

The lessons are appreciated!

[RF Overlord]

I'm still a bit unclear of the stat and plugs...is it that they allow for a more aggressive tune that gets the power?That's it exactly.

[Captain Steve]

Yeah, it's like running higher octane fuel. By itself it's useless and may even hurt mileage and performance, but it's real effect is to increase your safety margin when your tuning is more aggressive.

So to recap, Underdrive pulleys = less parasitic drag on the motor = more available horsepower. Lower temperature thermostat + colder plugs = increased protection from detonation due to a more aggressive tune.

[GA-Marauder]

I have a couple of questions for some of you...
I've been reading many of the threads found a few mentions of some things that I'm curious about.

Particularly certain mods that come up. Often as reccomendations for new MM owners.

Why the colder thermostat and spark plugs? What's the expected gain? What's the actual gain? What are the potential issues?

What about the underdrive pullies? I know the theory behind them, but how effective are they? What's the drawbacks to them?

What's the dollar to performance ratio of these mods?
Underdrive pullies decrease the amount of HP to your electronics. The decrease is about 25%. This frees up HP to the wheels. It has negligible effect on the electronics, EXCEPT if you decide to add a Supercharger. Otherwise, its a free 10-15 HP at the wheels, give or take. The spark plug/thermo changes are ONLY applicable for a flash/chip, and they are arguably a bonus for this mod. I honestly don't know if they actually add any HP in this situation, but I know DR recommends them, and there are threads relating to this. Bottom line, minimum additional $ to add to the flash/tune. Hope this helps a little.:)

[GreekGod]

OLD SCHOOL- that's a phrase that is very 'groovy' lately (thanks to all the high quality ;) 'biker'/reality shows on cable/satellite TV?). I drove a delivery truck for a large West Michigan Ford dealer for 3 years from 1969 to 1972. I used to go to the Hastings Piston Ring Co. in Hastings, MI on occasion and they had a display rack with tech. handouts on it. My favorite was about piston ring wear in relation to engine temperature. It had a graph(s?) showing a huge increase in wear with only a SMALL decrease in engine operating temperature. I still have the print somewhere but can't find it now. What I'm getting at is-old school people knew of this big increase in wear and we should look back to the past before jumping into this low-temp 'stat idea. It seems to correspond with fuel injected Mustang dragracers finding a way to go a litter quicker in the 1/4 mile with just a 'stat change. If you only want to go dragrace your MM and don't care how long your rings and bore last, go for it. If you want it to last, think twice! Life and love is always a compromise and the mechanics of a gasoline engine is no exception. A 'stat's temp rating is only the rating of the temp that it STARTS to open. A 180 degree 'stat is not FULLY open until 200 degrees! Dennis is in Florida and those Southern cars probably have fully open 'stats 90% of the time. Hopefully some tech or engineer guy will read this post and correct my knowledge, update it , or confirm it. I also believe NASCAR competitors now run very high coolant temps (250 degree?) to extract the most hp for the hi-banks.

[Shaft333]

Greek...
Your point is clear. It's one thing that has stopped me from ordering an XCal2 and other stuff the past couple of times I was about to do so.
Especially now that I am an automotive engineer (for electronics) and know what goes into each step of the way.
I do believe mods like this can improve performance in the quarter, the 60, on the moon whatever, the real critical point is to what end do those mods do? Is it fuel mileage? Emissions? Price? Ease of installation at the factory? A carry over that's just behind current technology? Or is it longevity and reliability?

So say you find a mod that doesn't sacrifice longevity, how can I be sure that the maker of that part puts their design through as stringent a spec as the OEM component? I really can't.

It's a dilemma for me. :depress:

[RF Overlord]

Shaft:

You (and GreekGod) raise valid points.

Any time you change something from its factory spec, there's a risk that the change may not be for the better, or may provide benefit in one area while being a detriment in another.

Back in the early days of MM.net, we used to tell people that if you're not comfortable doing a given mod, especially while a car is under warranty, then DON'T do it. Without doing extensive (and expensive) durability testing, there is no way to PROVE that a mod won't have any negative impact further down the road, so you just have to be willing to take that risk, however small, to get the desired short-term benefit.

Having said all that^^^, most of the mods available to us are not new in themselves, it is only their application to the Marauder that is new. Underdrive pulleys, less restrictive exhaust systems, more radical gear ratios, transmission coolers, etc are all well known mods that have proven over the years to be safe, if used as intended and not abused. The same is true, to a lesser extent, about chips and blowers. Maybe my motor would have lasted for 200,000 miles without the Trilogy blower, and only 150,000 WITH it...I have to decide if the tradeoff is worth it. (and I think it is)

IMHO. YMMV. IIRC. NFG. OICU812.

[Shaft333]

Is true. They are proven. But not necessarily to last or not hurt what they are mated to.
My last car 95 Integra LS with 150kmi at trade-in only had problems with the parts that I had "upgraded" or monkeyed with.

Except, oddly enough, the header. And that was the one part that the manufacturer only said would last 5 years at the most. It didn't even develop a leak.

I'm torn. I want the car to go 150kmi with this car, but I'm also a fan of tinkering, modifying and upgrading.

I probably should'a bought a boring car.

[Sully008]

Is true. They are proven. But not necessarily to last or not hurt what they are mated to.
My last car 95 Integra LS with 150kmi at trade-in only had problems with the parts that I had "upgraded" or monkeyed with.

Except, oddly enough, the header. And that was the one part that the manufacturer only said would last 5 years at the most. It didn't even develop a leak.

I'm torn. I want the car to go 150kmi with this car, but I'm also a fan of tinkering, modifying and upgrading.

I probably should'a bought a boring car.

I'm also a fan of modifying. See my sig for my minor mods to this point. I have the 5 year extended warranty on my car, and so far I haven't had any issues (knock on wood). This is my daily driver and I plan on keeping it until it finally needs to be brought out back and shot (if it ever comes to that). Really, the mods you list do wake up the car. I'm glad I did them.

Next plans are UD pullies and intake spacer. That should hold me until I save up enough money for a S/C (by that time, I'll have run out of warranty anyways.
:burnout: )