VQ35HR or LS1 my S14?

[JRas]

So I decided to work on my "career" and put my project on hold. Car has been sitting in the garage for 5 years... along with a VQ35HR engine.

I decided I want to finish it but I need some advice. I can't make up my mind if the VQ35HR is worth it, or if I should go an easier route perhaps LS1.


I originally wanted to go VQ35HR being it was a Nissan engine plus I was hoping to lose weight, and gain a lot of power, while still being NA. I was working at a Nissan dealership as well (resources).

Now, I don't have the time or resources I did but after the deployment I should have the money. The problem I'm having is I'm not sure if I should continue with a VQ35HR swap or an LS1.

Problems I'm having with VQ35HR swap:
Hood clearance issues, engine sits too high doesn't allow the hood to shut. (looked into replacing the oil pan to make it sit lower, as well as intake manifolds and more recently ITB's )
Wiring ( debating keeping NATS or removing it, security vs ease )
Speedometer ( ECU reads from differential, looked into doing an S15 speedo setup, car currently has an S15 HLSD, removing 4.63 gearing anyways swap pumpkins?, or something on the lines of GPS speedo )
Engine Mounts ( nobody really makes them, VQ35DE mounts with a spacer to raise one side )
Starter and Steering ( one guy went RHD, another was able to do it.. think he's on this site actually )
ECU (Factory or AEM, etc)

LS1 seems like the swap is much easier, mounts made for it, wiring is easier, fits under stock hood, makes more power and easier/cheaper to make more, less electronic bull****, and mechanical throttle.

Is it worth it? I like the idea of a VQ, but I'm wondering if it's going to be cost effective and more of a headache.

I don't need 500HP, I just want a fun light car for the track. I'm thinking 300-350whp. Ultimately I just want to do some Time Trials, not sure on rules and restrictions for these swaps.

Opinions?

[Def]

LSx is pretty easy these days, but the cost of a good condition T56 is through the roof. I've seen $1.2-1.4k for ones with over 100k miles on them and not refreshed. So by the time you get even a barebones swap put together it's like $5-6k unless you're doing a ton of fab yourself.

Any reason why an SR isn't on your list? 350 rwhp is easy street with a stock SR, and reliable forever from a power standpoint. GT2871R .64, fuel, tune, intercooler, exhaust, then a few supporting mods to handle track duty which you'll be doing on any engine (probably at more expense).

[Z28ricer]

Def's on the right track with this one, if you're honestly certain you just want 350HP range, SR all day.

In either case though i'd take some form of LS swap over a VQ every day of the week, unless trying to fit into a select few sanctioning rule sets.

[Def]

Yea, over 350 rwhp day in and day out on an SR starts to make things a bit tricky. So at that point, I think your engine choices open up if you really want something different.

Getting a VQ35HR up to 350 rwhp is going to take an act of God or a big bank account, while the SR will do it without complaint with pretty minor mods really.

[JRas]

LSx is pretty easy these days, but the cost of a good condition T56 is through the roof. I've seen $1.2-1.4k for ones with over 100k miles on them and not refreshed. So by the time you get even a barebones swap put together it's like $5-6k unless you're doing a ton of fab yourself.

Any reason why an SR isn't on your list? 350 rwhp is easy street with a stock SR, and reliable forever from a power standpoint. GT2871R .64, fuel, tune, intercooler, exhaust, then a few supporting mods to handle track duty which you'll be doing on any engine (probably at more expense).

I want to stay NA, keep it simple. Everyone I know that had an SR is constantly working on it.

Def's on the right track with this one, if you're honestly certain you just want 350HP range, SR all day.

In either case though i'd take some form of LS swap over a VQ every day of the week, unless trying to fit into a select few sanctioning rule sets.

That's something I should be looking into more honestly, I should be building the car around the rulebook. If I want to be competitive ever

Yea, over 350 rwhp day in and day out on an SR starts to make things a bit tricky. So at that point, I think your engine choices open up if you really want something different.

Getting a VQ35HR up to 350 rwhp is going to take an act of God or a big bank account, while the SR will do it without complaint with pretty minor mods really.

I'm really okay with just going from a KA to a VQ, in the future those may be my goals.

313whp: longtube headers, intake and exhaust, nismo street cams
http://www.youtube.com/watch?v=iU2h0JTq2fk

414whp: ($)
http://www.youtube.com/watch?v=oBKAWi0upvg

[RalliartRsX]

I want to stay NA, keep it simple. Everyone I know that had an SR is constantly working on it.

I have a feeling its more of the owner of the SR than the SR itself being the issue. Lack of prep work and negating things like temperature control will cause said impression (that and a myriad of other things).

Example: I would never use Godspeed traction arms on my track (or street car for that fact) car for the simple fact of crappy quality and a good chance of them failing once I decide to use up all the track by driving over FIA approved rumble strips.

A properly prepped SR at 350WHP will last all day on track it temps are kept under control.

[240sxTTC]

If you're going to compete in NASA Time Trials then based on say 2700# comp weight and 350whp, you'll be in an unlimited class; TT1-3. The engine mfr or type (NA or boosted) doesn't matter. I'd suggest reading through the below rules and playing around with the calculator. I'd target TT3, which is what I'll be in, because if you go above it you'll need DEEP, DEEP pockets to be competitive. Let me know if you have any questions.

Rules => http://www.nasaproracing.com/rules/time_trial_rules.pdf

Calculator => http://www.nasaproracing.com/racing/...r_2014_v1.xlsx

[josh_s13]

With a vq in hand, no love for the SR, and power goals of a modest 300 to 350whp, I'd go VQ all day long. If you were wanting 400++whp, then LS. Of course the LS would be at your power goals from day 1 of having it in the car and running at a probable weight penalty.

[Beejis60]

If you were gonna go all out with a motor swap, I'm biased towards LS but I'd consider an SR if it was from a good home... I sold my SR/trans/ecu out the door for $1900 cash; idk what the going rate is for an SR but I felt that was good enough sale. That's about half the cost of an LS1 and T56 and some accessories, but I'd personally get a TR6060; it's more robust and almost the same price as a good T56.

[Def]

I want to stay NA, keep it simple. Everyone I know that had an SR is constantly working on it.



That's something I should be looking into more honestly, I should be building the car around the rulebook. If I want to be competitive ever



I'm really okay with just going from a KA to a VQ, in the future those may be my goals.

313whp: longtube headers, intake and exhaust, nismo street cams
http://www.youtube.com/watch?v=iU2h0JTq2fk

414whp: ($)
http://www.youtube.com/watch?v=oBKAWi0upvg

Even that 313 rwhp setup is pretty $$$ considering an SR will do that with $200 injectors, $60 Z32 MAF, and a GT2871R. A T28 would almost have a chance of doing that if you really run it flat out.

That 414 whp engine probably isn't long for this world given the revs it's turning...

[240sxTTC]

The problem is area under the curve. Look at a dyno graph of a C5Z's LS6 or even a C5's LS1. The area under the curve of 350whp LS6 is much different (larger) than a 350whp SR20DET. The C5, C5Z, C6 and C6Z are still the cars to beat in the unlimited classes. There isn't a rule on torque so you need to maximize it. The torque curve of an LS1/3/6/7 is FLAT so best to at least have an engine with similar area under the curve! The Vette's are even adjusting % throttle (DRW) to flat line whp once rated pwr is reached.

An LS based engine is my vote!

The options are endless (4.8, 5.3, 5.7, 6.0, 6.2, iron block, aluminum block, etc) and there are plenty of used engines, new short/long blocks, and complete engines available. GM just happened to put an LS in just about all of their vehicles with over 285hp. Plus the aftermarket support is also endless for the LS based engine.

[Z28ricer]

All of the trouble of the swap, costs of that set of cams (im sure those are pricey for 4 cams), headers (probably going to be custom i'm guessing for something tuned to make the power and fit in an schassis), tuning, etc to make 313whp ? That's pitiful.

If you're wanting to have something competitive in a sanctioned class setting, it makes it difficult for the LS based stuff, there are classes where you can drive it sure, but most of the classes where it should be fair to run it end up bumping you out because of something usually needed for the swap, like crossmember modification, firewall/trans tunnel modification, etc.

Any issues you've witnessed with SR issues are due to the users/installers, and they would have had the same issues with another drivetrain, you just witness it more because of the number of people with SR's.

[Def]

The problem is area under the curve. Look at a dyno graph of a C5Z's LS6 or even a C5's LS1. The area under the curve of 350whp LS6 is much different (larger) than a 350whp SR20DET. The C5, C5Z, C6 and C6Z are still the cars to beat in the unlimited classes. There isn't a rule on torque so you need to maximize it. The torque curve of an LS1/3/6/7 is FLAT so best to at least have an engine with similar area under the curve! The Vette's are even adjusting % throttle (DRW) to flat line whp once rated pwr is reached.

An LS based engine is my vote!

The options are endless (4.8, 5.3, 5.7, 6.0, 6.2, iron block, aluminum block, etc) and there are plenty of used engines, new short/long blocks, and complete engines available. GM just happened to put an LS in just about all of their vehicles with over 285hp. Plus the aftermarket support is also endless for the LS based engine.

A 350 rwhp GT2871R SR setup is going to have a pretty damn flat torque curve over its 3.5k RPM powerband. Below that of course the NA engine crushes it, but I think if you graphed them both over the top 3.5k RPM of their powerband the SR will hold up better than you think.

[240sxTTC]

C'mon man! I'm a fan on the SR20DET engine also but it's no LS6. I should have added, the LS6 makes the same or more wTorque than whp and it's flat. The problem is until there's a rule on torque, if you don't have the same as the big engine cars you're at a disadvantage before you even get on the track. I agree the SR is a great engine but stock the LS6 will beat up on it in the same car.

[Def]

I don't know, they felt pretty close to me except below 4k RPM and the slight transient response of the turbo when getting back into boost.

And yes, the LS6 makes much more torque for the HP, but that just reinforces that it falls off pretty hard up top (torque wise) while the SR has a much flatter torque curve.