Well, I'm confused now....

[auxilary]

I am now very heavily swayed towards an sr20det motor for the Z. It can be had quite cheap, and it's a good track motor due to its weight and positioning in the bay. I already have most of everything needed for a v8 swap (originally planned for an lt1/t56 combo), got the JTR kit minus the speedo cable, camaro alum. radiator, etc. The post for best track motor in alternate L6 forum gave me the idea and i've been doing some research.

 

Downside is fabbing new mounts for it, and custom driveshaft

 

SR20DET, the 2.0 liter 4 banger silvia turbo motor from japan. I've checked around prices, and it's not all that expensive. There are laws in japan that tax cars with

over 35k miles or so, so the imported engines all have under 40k on them, which is just basically broken in.

 

an sr20det from an s13 (90-94 240sx) with a 5 speed tranny ECU and wiring harness is 2400.

an sr20det from an s14 (95-98 240sx) with a 5 speed tranny ECU and wiring harness is 3500.

the S15 ('99-present) motor comes with a 6 speed, limited slip r200, halfshafts and driveshaft for 5k.

 

here are the specs on the motors:

 

S13 SR20DET:

Displacement: 1998cc (2.0 liter) Cam type: DOHC 16

valve, chain driven cam sprockets

Bore and stroke: 86mm x 86mm Compression: 8.5 : 1

Horsepower: 205hp at 6000rpm Torque: 203 ft/lbs

at 4000rpm

Stock boost: 7 psi Throttle

body bore: 60mm

Turbo specs: Injector

size: 370cc/min

Compressor: T-25, 60 trim 56mm BCI-1 compressor.

Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.

Center Section: Journal bearings

 

Aluminum alloy block and head with steel alloy sleeves.

Distributorless, crank angle sensor activated ignition, direct fire coil

packs. Stock SR's come with an internal wastegate, a knock sensor, a

side mounted intercooler and a bypass valve that is routed back into the

intake after the MAF before the turbo. Stock turbo outlet is 1 7/8

inches, inlet and throttle body are ~2 1/2 inches.

 

Performance:

 

The stock turbo will be safe to 13-15 psi. After that, the turbo is

past its efficiency range, and power increases will fall off and are not

worth the risk of turbo damage. The engine should produce 230-250 RWHP

at safe boost.

 

Required Parts for the install:

Engine, transmission, alternator, starter, power steering pump, Crank

Angle Sensor, ECU, harness, MAFS, Power Transistor / Ignitor Chip.

 

S14 SR20DET:

Horsepower: 220hp at 6000rpm Torque: 203 ft/lbs

at 4800rpm

Turbo specs:

Compressor: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing

Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.

Center Section: Ball Bearing

 

Variable valve timing system and a different turbo are the significant

changes from the S13 SR20DET engines. S14 uses 'low port' intake

design vs. S13 'high port' design.

 

Performance:

The stock turbo will be safe to 13-15 psi. After that, the turbo is

past its efficiency range, and power increases will fall off and are not

worth the risk of turbo damage. The engine should produce 250-260 RWHP

at safe boost.

 

Required Parts for the install:

Engine, transmission, alternator, starter, power steering pump, Crank

Angle Sensor, ECU, harness, MAFS, Power Transistor / Ignitor Chip.

 

S15 SR20DET:

Horsepower: 250hp at 6000rpm Transmission: 6 Speed,

Close Ratio

Injector size: 480cc/min

Turbo specs:

Compressor: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing

Turbine: Inco turbine wheel. Cast divider wall between turbine discharge

and wastegate.

Center Section: Ball Bearing

 

Additions: 6 speed manual transmission. The 6 speed can be used on the

S13 and S14 motors with no modification using the S15 driveshaft.

Speed sensor is located in the differential.

 

Performance:

The stock turbo will be safe to 15-18 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The engine should produce close to 300 RWHP at safe boost.

 

Required Parts for the install:

Engine, transmission, alternator, starter, power steering pump, Crank Angle Sensor, ECU, harness, MAFS, Power transistor is built into each coil. S15 differential and Driveshaft.

 

This isn't too expensive, a light block, and those ratings (pre boost raise) are without intercoolers, I think. The fact that the block's built to handle ample amount of power is nice, with 8.5:1 CR the boost can be almost doubled from 7psi stock. Cheap increase of nearly 50 whp say I decide to go with the s14 motor, 220hp stock, crank the boost to about 10-12 and be happy with 240-250rwhp. (rice math? Eh, probably not). I'd swap out the rear diff (ugh...not again!) to something like 3.9/4.11 limited slip then.

 

Your guys' opinions? Wrong forum? (I figured i'd ask chevy folk for devil's advocate opinions:) )

[dsommer]

Go for it!!! Turbos are coooool

 

Now sell me your JTR kit if you're serious.

 

David

 

dsommer@mortonsalt.com

[Guest Anonymous]

I like the idea alot, I've even considered pulling the V8 and putting a SR20DET or a 7MGTE in its place. But I'll just wait, it'll pass and when I have a turbo on that V8, I'll have all I need, to end up in the hospital... (not that I don't have that now if I act a fool). Someday though, I'll find something to put a SR20DET in, I'd love to build a Locost and stuff one in there, that'd be the ticket..

 

Regards,

 

Lone

[deMideon]

I guess I don't really get it... why go through all of that work for less than 300 hp? One reason I am going with an SBC 377 is because I modifed an L6 out of being really driveable on the street. I just couldn't get the HP out of it and keep it something I would consider reliable. IMHO the SBC is the most cost efficient way to get a reliable engine and have a very driveable car with tons of power with lots and lots of room to add more HP. With aluminum heads, water pump, etc etc... the weight issue is pretty much eliminated and I am going with a small dist so I'll be set very far back for the best weight distribution. Maybe I just don't know what the benefits are of using it?

[Guest Anonymous]

Weight... Its still almost half the weight of a chevy, it sets back as far and you'll note he was talking mid 200's at 7psi of boost. Rock one of those little guys up to 14-18 psi and you'll easily get 300hp and way more.

 

The SBC with aluminum heads and pump and moving the battery makes it about as light as a L6. Handling isn't hurt much if at all (maybe better with the weight distribution).

 

Cut 200 lbs under a L6 or SBC (probably a bit more if you look at the size of that tranny) which brings the car down to 2100 2200 lbs.

 

Power to weight ratio works as we know, so there ya go, I think thats the reason for it. I like the chevy's alot too, mine is infinitely drivable and has torque everywhere in nearly every gear but 6th.

 

I like the idea of the small boosted 4 in a Z, but I do like the usefulness of shifting at 2-3k and being in the fat part of the torque band for my engine, a boosted 4 I think would be great wound up, but you'll be stirring the box far more than I am to produce similar power (and not similar torque ever).

 

Anyway, unless I missed something, thats some of the issues he'd be looking at IMHO.

 

Regards,

 

Lone

 

Ps: If import racing is important to you, the SR20DET might be a good go, it is Nissan and therefore the same make swap, which is kosher from my limited understanding of import drag racing.

[pparaska]

I must admit, I have to agree with Demidion in some part - I can't see going to the trouble of doing all the work to swap that motor in if a tweaked output of 300hp is all there is to be had without a bunch more modification and $$$ - unless 300 hp is all you really want and you want to do the swap just to do it!

 

And of course, there's nothing wrong with that!

 

For near the same money as the S14 setup, why not get an RB26ETT, the right oil pan, make some mounts, and go for it! Unless you're looking for the super light weight of the SR20ET to bring the weight and polar moment of interia down.

 

To each his own - we all don't have to have the same engine, nor do we all want 400+ hp under the hood!

[Tim240z]

nor do we all want 400+ hp under the hood!

Aw Pete...say it ain't so!!

Tim

[Owen]

I would do it, even though I know Tim240Z has and will disagree with me

 

If you have the time, I would contact Signal Auto in Torrance, CA. I met a guy there who told me they are doing the same thing, SR20DET into a 240Z. They might give some useful info.

 

Owen

[Mikelly]

I'm looking at this setup for our 240SX. Only other thing I would need is a clutch pedal assembly since ours is an automatic car, and I'd rather have a manual shift. I think a lot of folks are doing cool stuff the the SR20 because of the weight and boost potential...

 

Aux, I say do it... I agree with Pete that 300HP isn't a lot, but realy if you add up everything in a small block chevy buildup, you'll get nickle and dimed to about the $3000 level anyway, and it sounds like you get everything you need with that package minus the intercooler and assiciated aftermarket electronics/ BOV/ BC/ Turbo Timer...

 

Mike

[Tim240z]

I would do it, even though I know Tim240Z has and will disagree with me

Take that and that and that ....

he he

 

Tim

[randy 77zt]

in an early (70 to 73) light weight z a sr20 det set way back against the fire wall would make a great track car.suggestions for mounting engine-cut off oem mounts from cross member and put engine on a new cross member behind original.you could put some angle iron on top of frame rails and build a tubular crossmember/engine brackit with some urathene bushings.i have many fabrication tools-send me an email when ready.car will probably end up 45%/55% front to rear.the engine bay will have lots of room.could probably move radiator back and run a huge intercooler and have it all hidden.

[auxilary]

thanks randy! I'll definitely hit you up when I'm ready. you going to the norcal bbq in july?

[DavyZ]

Aux,

 

I'm seeing the failure of my ways; my mentoring has not paid off at all--you are just young, free-spirited individual who can't take advice from his wise elders. So here you go:

 

 

Actually, I think the turbo four would be a great track motor (as Randy pointed out) if you plan on keeping your car as a track only car you indicated in the past. If you plan on lightening the car up even more, the motor starts making sense.

 

HOWEVER, it cannot be denied that a SBC is the easiest and cheapest way out. It is cheap to add 100 hp to the engine, but taking 300 lbs off the car will be more difficult.

 

What I really think this all boils down to is simply this (pay attention):

 

You feel 'strange' having to shift a V8 at 5000 to 6000 rpm because you daily drive a 4 banger that redlines much higher than that. In other words the torque feels good, but the revs don't equate with what 'feels' right? Am I getting warm?

 

So, may I suggest an alternative:

 

1) Destroke an LT1 (as some others have suggested) to get maximum revs and a higher power band. You get your EFI and a V8!!

 

2) Build a 377 or a 350 (both destroked motors) with balanced & forged rotating assemblies for maximum revs.

 

3) Be a chump and just go with the SR motor!!

 

Either way, once I build the SECOND motor for my car (turbocharged V8) you will become road fodder for my intake at Thunderhill, regardless of the 4 banger you choose! lol

 

I'll help you in whatever you choose, Buddy. At least you have a car!!!

 

Davy

[Guest Want aZ]

OK, I can understand both sides of this arguement...I would love to have a chevy powered Z, but on the other hand the import scene is doing some amazing things with the SR20DET, somewhere in the neighborhood of 600-700 HP, with larger injectors, turbo and intercoolers...it can be done, only reason Im on both sides of the fence ive built quite a few chevy 8's in my time, but my son is into the import scene and gets all of the mags...now an SR20 with somewhere around 550 HP hooked up to a 6spd would be fun you have to admit....so what do you think now???

[pparaska]

Well, with the relatively medium low starting price for that engine/tranny/ecu, if 550 hp is not an astronomically priced upgrade, I'd say go for it!

[Guest Anonymous]

Aren't you for sure into the bottom end of that motor to put out 550 hp? As Pete says, if its economical then yeah baby, sounds great. I suspect you'll be buying minimally better rods and pistons anyway. If you have to get into the motor to do all that, (and IMHO and I'm not doubting you at all, 6-700 HP would require quite a turbo/intercooler/injector upgrade) then the pricepoint of this project leans me back towards a chevy.

It comes down to what do you REALLY have your heart set on, if its a V8z, doing the other will only mean you'll be building a V8z in the future anyway, so do it now if thats what gets you off.

 

Regards,

 

Lone

 

Ps: For what its worth, I miss the crap out of my car right now (which is 770 miles away at the moment), you'd like the V8 Aux, with its midrange torque it makes things disappear in the rearview mirror and thats with my low-end motor.

[auxilary]

Damon: I'm not interested in the sr20det because of the 'import scene' I just see it as one of the better options for a car that can be well balanced and light. Also, on a sidenote, the 6 speed isn't the better option for the sr20det because it's the same size transmission as the 5 speed (same bellhousing, etc) but the gears are made a little thinner than the 5 speed to squeeze the extra gear in there. Unfortunately, that also weakens the transmission overall since the gears are thinner.

 

Lone: Oh, believe me, I am aware of v8zs I've driven Mike D's (73botiz) Z, Don Manzo's 11 sec monster, and leonard took me for a spin in his 327 powered Z. I definitely don't doubt the torque and power of the motors. It's just for general reasons that the sr20det seems like a good option. I built the car primarily for handling, it still needs a little work, but right now, it does pretty well even on crappy tires. (ask davyz, he's driven it several times).

 

Oh, and to answer your question, it's true: the stock bottom end on the sr20 motor can hold up to abuse of 500hp.

 

Davy: i know i know I am still debating, but it's just that the turbo idea seems unique and prospective. (it's still a hybrid, right? hehe). My friend introduced another idea also - a ka24 motor with a custom turbo. THat's the 240sx (US Spec) 2.4L inline 4 block with a custom f-max turbo kit that is produced for about 2500. But that might turn out to be slightly more costly.

 

A destroked LT1 is a good idea, and I'm not leaving that option out. After thinking about it, either motor will have to be rebuilt anyways, and performance components will be added to either. In that case, SR20DET still stands as a strong contender because a rebuild will yield ability to crank up the boost higher, and possibly replacing the turbo with a bigger unit. At the moment, it's all future planning, and project won't be started until I have a steady job and a garage I can hog up for at least 6 months.

 

Thanks for your guys' input!

 

ps. and Davy... i'm your FODDER for t-hill? BWHAHHAHAH! Good one We'll just have to wait and see which is the better driver, won't we?

[deMideon]

For myself it comes down to reliablity, driveabilty and where can I go from here. For me the SBC 377 I am putting in will give me about 450 HP and be very driveable and reliable. If (when!) I need to bump up the HP, I know I can do it with what I already have and minimal additional expense. IMHO I wouldn't think you would get 500hp out of a 4 cyl reliably or end up with a very streetable car. But that is what I would consider reliable and streetable! I am sure some would feel differently!! But I like that I can take the SBC a long way before it gets to be too much of a PITA.

[Guest FullBoostOrBust]

I Actully bought my 1971 240Z a month ago for the S13 or S14 SR20DET project. I plan to upgrade the engine before installing with a metal head gasket, tubular exhaust manifold, 550CC injectors, Walbro FP, Apexi SAFC2 fuel computer, Silvia front mount intercooler and a Garrett GT25 ballistic series ball bearing turbo. We are talking 350Whp in a front midship car that weighs around 2,200lbs. i've allways been a fan of great weight distribution and a light chassis to man handle, my last project was a 91 mr2 turbo, a kick A$$ car to drive. There is nothing wrong with decreesing displacment (or weight) when its to YOUR driving pleasures.

 

I found a mate for AU who actuly moved the mounts on the engine block rather then the chassis, craddles the engine from just behind the crank pully, very effective looking.

 

Regards,

[David K]

The sr20det engine/tranny combo is like 450 pounds.