rokblok

iTrader: (1)

I have an '84 that I did a 3RZ(2.7L) swap in. I am trying to get Tacoma/4runner with a 5spd owners to chime in on their highway cruise speeds and RPMs. In my '84 with the G52 trans, and 4.10 gears, I turn about 3K RPMs at 80mph. Around 27-2800 at 70mph. Mileage is anywhere from 16.5 to 22.5, depending on how lead-footed I am.

I have a set of 4runner 4.88s that I was gonna swap in, but I don't want to be turning 3500 RPMs all day long. I travel the country for work in this truck, so reliability and longevity are very important.

Would 3-3500RPMs be to much for extended periods?

Texas_Ace

If the power you have now is ok no reason to install gears. Only reason to do gears is if you don't have enough power.

rokblok

iTrader: (1)

I have power, but it seems like I have my foot deep into the throttle to keep it going, and it can still drop a few MPH. Inside of my exhaust is very sooty, and I feel like my mileage could be a bit better, or at least more consistent.

Texas_Ace

Gears will greatly effect how much throttle it takes to maintain speed and overall power.

Mileage sounds about right. if you have to give it a lot of gas to maintain speed your mileage may not change much with gears actually.

You could add a turbo to it as well, a low boost turbo setup would net you about the same results as gears, the extra power would allow it to not need as much throttle to maintain speed and it would not turn as many RPM's as gears.

Overall about the same amount of wear with either setup and about the same chance for reliability issues if done properly, which is not that much. Just another option.

My MPG actually went up with a supercharger.

gk5

In my bone stock 3.4 5 speed taco with 4:10s I run 3k at 80 mph for extended periods ... Pretty much long road trips I like to keep 70-80 mph at first it worried me but it comes from the factory that way so I guess its not that bad but I wouldn't run 4:88s unless your had 35" + tires.

nothingbetter

I'm confused...whats your reason of going to a steeper gear? Are you going to get larger tires?

3500 seems excessive. Occassionally wouldn't be bad. We all forget to shift sometimes. But constantly on a highway trip, its your choice. We can't tell you yay or nay, but can help you make your choice. With a higher rpm means more combustion cycles, which means more heat, which will put more stress on your cooling and oil system. Also means your tranny and t-case will build up more heat and more bearing wear on everything (waterpump, oil pump, trasnny ect)

I'm not disagreeing with you ace, just to clarify as we don't want other people (noobs) who read this to get confused. Different gears won't actually change the amount of power put out. We change gears, to compensate for a larger tire size, keep the speedo at the proper place(ish) and keep within the factory powerband. As well as slow down crawling speed and get more low end power (from moving the powerband) Simply put, gears change your engine rpm and can create the feeling of more power.

Texas_Ace

Right, thats what I meant. I am well aware it doesn't give you more power at the crank but ask the butt dyno the same question and it will swear up, down, and sideways that it gave you more "power".

You are correct in how gears are used on this board, now go to a drag racing board and things are a bit different.

I personally am of the mind to leave the gears alone and add more real power, power can be turned on/off as needed, gears are an all or nothing kind of deal.

rokblok

iTrader: (1)

Thanks for the replies. I have only the 33s for now. I willbe stepping up to 35s as soon as these wear out. Which may be a while, or if I can swing it, I will put these on the 40 and then get 35s for the Pickup. I may just stick with the 4.10s til the 35s happen. Or I may just swap out the rear to 4.88s for a few days to see the difference in mileage & power application.

So the general consensus is 3500RPMs is a bit high. But around 3000 RPMs is the norm from factory?

And TA, I have contemplated the LCE Performance low boost set up. Just not to keen on loosing the Toy ECU and various factory components... Reliability and longevity is a deal sealer for a while...

Texas_Ace

While not an expert on the 3rz I have seen a lot of guys bolting a turbo onto an otherwise bone stock 3rz as long as they keep the boost low. I have seen 8psi in this setup running on 100% oem electronics.

Check out www.Customtacos.com, they have tons of info on this. There are also a lot of other options for turbo kits then LCE, KOracing for example.

rokblok

iTrader: (1)

I will investigate the turbo set ups. My engine was rebuilt with LCE Performance master rebuild kit so its not EXACTLY bone stock. Although I wouldnt go more than 7-10psi. I have to have reliability before power... And 4.88s with 35s might be ok anyway. $2400+ and possible ECU kit ($1500)for turbo set up is a big leap....

Texas_Ace

Wow, those kits are expensive, seems like you should be able to get it a fair amount cheaper then that since most use T3/T4 turbos (not a fan of them personally but they are cheap). I would do some reading on the site I listed before, they have a ton more info on this.

drkblu4runner

if you want better mpg go the speed limit. turbo or super charger will almost never be cost effective and will reduce reliability.

rokblok

iTrader: (1)

Thanks for all the input. TA, I maybe PMing you about some turbo setups. I'm not a Garrett fan, since I'm an older Audi/Porsche fan, I tend to lean more towards KKK turbos. And I have access to those....

I prob couldn't do a kit from someone, but maybe a pieced together set up over time...?

Texas_Ace

The turbo itself is the easy part, got to get the rest of the stuff together first. If you can fab up some of the parts piecing it together can work well, otherwise you can end up with parts needing small modifications to work together.

I am not a Garrett fan either but KKK is also not a good turbo anymore. Both are old school by modern standards (kkk more so then Garrett).

If you want a good quality modern turbo Precision makes some of the best performance turbos on the market right now. Although the smallest turbo they have with CEA tech (only real reason to get a turbo from them) is the 5858 which should spool in the mid-low 3k range.

Honestly for the power goals most have with these trucks the T3/T4 turbos are cheap and they work, just far from the best turbos around from a performance standpoint. Course I generally pick out turbos with HP goals of 700whp+ in mind so I have slightly different tastes then most truck guys.

rokblok

iTrader: (1)

Right... Cuz I need 700 ponies in my daily driven, Toy pickup... Lol

I have a little turbo at home, that I think came off some DSM vehicle. Eclipse I would guess. It was originally slated for a turbo project on a ~1,000cc bike. I will have to examine and research...

Texas_Ace

Never know when you might need to tow a semi out of a ditch lol. For the most part I put that kind of power in cars but a fast truck can be a lot of fun as well. Got plans for my 4runner and a 6466 turbo (900hp capable turbo), will have to work out a transmission option that can hold the power first though.

If it is a DSM turbo most likely either a 14g or 16g, both are smallish turbos. It might be a 20g, if so that is a better match for your motor. 20g will spool ok and should handle your goals fine. Even the smaller turbos will work, just be a little restrictive on the exhaust side and gain you almost nothing in spool.

vikkz

i got a 98 taco with the 3rz and 5speed and your rpms and speed sound about the same as mine, ill be around 2700 going 80mph and about 2200 going 70.

Im also going to put a turbo which i got from an eclipse that my brother in law had and well he put a bigger turbo and let me have the stock one. From what he told me which i dont know nothing about turbos, is that its a 20g turbo and said that it would work perfect for what i want to use it for.

Not sure when ill put the turbo on but i believe it will be in a month or two since im heading out of state to work for a while.