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Mileage engine swap question.


battlemac

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Cummins makes a 4cyl turbo diesel motor that is fairly stout so i am told. They were placed in a lot of the ford vans. With an adapter, they bolt directly up to a ford 5spd trans.

 

(my plan if i ever get a CJ...)

 

 

Thats the 4bt, I guess it is in some delivery trucks and like he said bolts with an adaptor to a stock chevy or ford trans. In the latest Diesel Power Mag they built one up to 400 hp pretty easily and put it in a Bronco and "30 mpg".

 

On the turbo mileage if you have a stock turbo L28et which has peak boost at 3000rpm will you get better mileage driving on the highway at 4000 or 3000? Im guessing your making more boost so your using more fuel. Wouldnt a motor with peak boost around the top end of the motor get better mileage then one at a lower RPM?

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boost isn't directly related to RPM, it's about load and throttle. You need air entering to create air exiting, you need air exiting in order to create boost.

 

Most turbo cars don't create anywhere near full boost at cruising speeds unless they're running mild boost through most of the rpm range (like 3-7psi depending on displacement and head flow). From what I've seen even super HIGH boost cars can still get similar MPG than the same engine running less boost, so the main factor seems to be foot position, not boost quantity reached.

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Move to Tuolumne county with me, then you don't have to worry bout $h!t, that's right, one of 2 counties in the whole state that don't have bi-annual smog laws. Any turbo configuration, who cares. Just don't let the po-po's pop your hood.

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It seems like enough options that meet what you were looking for have been given. I have basicly seen this same thread done by different people in different places quite a few times. The thing is that if you want to be 100% legal then just leave the L24 stock. But you want more horses... so you have to take a chance. What's the difference between the swap being legal or illegal if your car is smog exempt and will never be checked? I've never heard of a cop opening a hood just because he felt like doing it. They might check if they caught you racing... in which case you will get in trouble even if you had the stock L24.

 

So just choose the engine you like better... and start the swap.

 

Oh and BTW... it'll take you quite some time of good gas mileage to make up for the cost of the swap.

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It seems like enough options that meet what you were looking for have been given. I have basicly seen this same thread done by different people in different places quite a few times. The thing is that if you want to be 100% legal then just leave the L24 stock. But you want more horses... so you have to take a chance. What's the difference between the swap being legal or illegal if your car is smog exempt and will never be checked? I've never heard of a cop opening a hood just because he felt like doing it. They might check if they caught you racing... in which case you will get in trouble even if you had the stock L24.

 

So just choose the engine you like better... and start the swap.

 

Oh and BTW... it'll take you quite some time of good gas mileage to make up for the cost of the swap.

 

LMAO!! the whole time i was reading this im thinking " if this guy actually goes one of these oddball swaps hes gona spend a tone of money anyway" ...

 

Its like buying the hybrid civic my sister just bought and bragged she was spending less money than me and my KA-T 240sx (my daily). Shes paying and arm and a leg for the car and its still just a civic (civic = bottom of the line honda) Her resale value actually deplete's faster than a conventional gas emgine due to reliability and the older it gets the closer you get to the batteries needing to be change (which is actually 1/6 of the cost of the car brand new) we also figured out it would take her 8 years after paying the interest of the loan to actually gain money in better gas milage. The average new car owner only owns a car for 4-6 years depending on the area they live in...

 

SO i digress, IMO worrying about legalities and gas mileage while trying to out perform a stock RSX Type S in a 20+ year old car is rather silly, the SR and KA both get great gas milage even the L28ET gets good gas milage and all three are easily capable of 250 RWHP the cheapest way to go would be with an L28ET then SR then KA (as the KA is not a tubro engine and will need to be partially built for reliability)

 

-PSi

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Well thank you. Any one know how good the QR24 motors are in terms of performance and mileage?

 

Do you mean QR25DE?

 

SER / Altima base engine?

 

Decent performer weak head gasket, tons of tq, not a ton of aftermarket support but has a fair amount.. More an NA beast than made for boost. Peter Cunningham and Realtime racing made 275 HP froma QR but that was full race prep...

 

Reacts well to N/A mods...

 

Thats about all i know...

 

-PSi

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LMAO!! the whole time i was reading this im thinking " if this guy actually goes one of these oddball swaps hes gona spend a tone of money anyway" ...

 

Its like buying the hybrid civic my sister just bought and bragged she was spending less money than me and my KA-T 240sx (my daily). Shes paying and arm and a leg for the car and its still just a civic (civic = bottom of the line honda) Her resale value actually deplete's faster than a conventional gas emgine due to reliability and the older it gets the closer you get to the batteries needing to be change (which is actually 1/6 of the cost of the car brand new) we also figured out it would take her 8 years after paying the interest of the loan to actually gain money in better gas milage. The average new car owner only owns a car for 4-6 years depending on the area they live in...

 

SO i digress, IMO worrying about legalities and gas mileage while trying to out perform a stock RSX Type S in a 20+ year old car is rather silly, the SR and KA both get great gas milage even the L28ET gets good gas milage and all three are easily capable of 250 RWHP the cheapest way to go would be with an L28ET then SR then KA (as the KA is not a tubro engine and will need to be partially built for reliability)

 

-PSi

 

Hahahaha! Once I did some similar calculations and figured that you save more in the payment by buying the regular basic car than what you save on gas buying the hybrid. And about keeping the car for ten years or so... well... I sell cars and trust me... the probabilities are really low.

 

And to battlemac... think about what exactly is it that you want and need. And always keep in mind that there are a lot more costs to a swap than just the engine and transmission. I think you are just confused (I have been in the same situation). So just accept that you can't always get everything... and start thinking hard.

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Nuclear too rich for my blood. And I doubt I can find an electric motor that will work with the Z. What other options are there? I would really like to do Z with a diesel motor.

 

So the QR25 that is in the Sentra and base Frontier, are there any issues with the motor, like an oil problems? Between the QR20 vs QR25 which is a better motor? As in which makes more power, is stronger, has gets better MPG? I read on here that people are having issues with the drive by wire? Is there anyway to circumvent it?

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I think it will all boil down to what engine you want to use and how heavy your foot is. sounds like your looking to go the 4cyl route and your mpg's will be more dependant on the way you driver rather then what engine it is. And usualy the more torque the less mpg's but not always. I would recomend getting an engine with variable valve timing because they have a far more mellow low rpm cam profile which will help the mpg's and the high rpm cam profile will get you the power if you rev it up.

 

I didnt read the whole thread... are you trying to go turbo or NA? or does it even matter?

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Does not matter as long as I can get pretty decent MPG and at least 200hp. It looks like my best engine choice would be the VQ25HR, which makes like 0-60 in 6.8 seconds in the recently Skyline sedan and makes around 30mpg. But they don't make this engine for the North American market so was looking for a similar feature from an engine.

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QR motors are decent motors. The early motors were notorious for oil consumption and head gasket issues, but the later ones are fine. The head flows more than the SR head, but it's the connecting rods that are the weak point on those motors. I've met a few boosted SE-R Spec V drivers here in SD, and with a modest 8-10 psi, they ranged in hp from 265 to just over 300. That's pretty good in my book. There is one guy in Arizona who made a QR/SR hybrid motor and is over 500 hp.

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Well as long as I can make at least 200hp and 200tq I should be cool, even if its N/A and you couple that to what a 2400lb weight I should be doing 13 in my quarter and get 25mpg street(I think). What about an supercharger how well do they work on the QR25?

Is there another Nissan motor similar to the QR(excluding the SR and CA)? Is the Ka24 any better than the QR25? What is the weight of the QR25 could not find a substantial info?

 

Thank you for all the answers.

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So it is better than the QR? What is the redline of both? What about the milage which gets the better milage(mpg)?

 

Also I know the SR20det is illegal but the SR20 fwd is legal in the state of Cali. But is the SR20de rwd legal? And what is N/A potential of this motor and what milage could I expect out of it?

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