Best swap for a roadrace car

[ImportRacer]

That thought crossed my mind but I figured that would make a more suitable swap for a 1G RX-7...

[Tim240z]

Speaking of 1G RX7, I've driven a 1000hp (FW) 4.3 liter V6 TT RX7(Lingenfelter)...lots O fun.

Tim

[QWKDTSN]

If I was going for all out road race capabilities, either an SR20DET or 3SGTE. Hell, the JGTC supras run 500hp 3SGTEs and if they can do it so can we. I think the inherent lightness and high rev capabilites of an SR20 would do a road race Z car very well.

[ImportRacer]

Ive never thought about swaping the 3SGTE but that is a damn strong engine! Has it been done? One of my dream project cars would be a MR2 with a celica Alltrac drivetrain. How awesome would a AWD MR2 be? The 3SGTE would be a damn good engine to swap in there if it would be done easily enough...

[R0N]

If your talking about road racing, you would want a motor that would give the car a good balance. Not only would you want a 50/50 weight dist. But also you don't want a motor that's NOT top heavy, for example a older V8. It may give the car a 50/50 balance but since the engine is top have you don't give the car it's full handling capabilities. But on the other hand aluminum V8 would give a Z the best balance for road racing.

 

I would also select a JSPEC 13BT because the how small and light it is. The RB would give the Z lots of power but it makes the front a little heavy and throws the balance off some. Now if you make the Z AWD then I would go for the RB =)

 

Just my 2cents

[awd92gsx]

Personally, I'd consider this...

 

If you take a 1995-1998 2.4L Galant (or a 1995-1999 Eclipse Spyder N/T) block, fit in custom pistons (which are in the process of being built) you can bolt on the 1990-1999 Eclipse Turbo (GST-GSX) cylinder head (1990-1994 is 1G, considered better head - same for turbo and non turbo, 1995-1999 turbo cylinderhead).

 

The result is a torquey long stroke (100mm x 86.5mm [stroke * bore]) high revving (up to about 8500-9000 rpm) engine that spools most decent sized turbos very quickly. I've seen a 2.3L (2.4L crank in a 2.0L block) spool a 20G at a little over 2000rpm (full boost). You would have an effective powerband from about 2300rpm to a little over 7k rpm.

 

You can then couple this to either a Starion or a Toyota RWD tranny (using a custom bellhousing that is already manufacturered).

 

This engine will produce torque across the entire rpm range and will produce over 500hp easily. Any turbos/camshafts/parts developed for a DSM will bolt right onto it.

[Guest JAMIE T]

Honestly, why not just put a 280ZXT motor in it or turbo your existing motor. It seems to me, it would be way cheaper(more cash for other go fast parts like LSD rear, or brakes(slow down parts). Those engines are plenty strong and can be tuned for 500hp if you desired(LOTS of tuning and cash). But really 290RWHP is do-able with that engine.

[260DET]

A SR20DET would give you around 50/50 weight distribution. Around 500 hp is possible, although a block brace to contain engine block flex may be required at that level.

 

Lower weight for road racing is IMHO important in a Z, given that the body is not the stiffest around. Is engine size relevant to your class of racing?

[awd92gsx]

The 280ZXT engine is a great swap indeed...however, in a road racing application, it could be *iffy* on whether or not it'd be any better than just building up the N/T motor.

 

Even though I'm about to swap a high powered ZXT engine into my car, I also realize that with the addition of the turbo components, I am adding slightly more weight to the front of the car.

 

I haven't weighed my engine, but, I'm sure with everything attached, it comes close to about 500 or so lbs (I just had an '83 ZXT engine shipped to me at 720lbs, but it had a few extras in it [including the crate])

 

Now, compared to a rearward sitting hipo 4 cylinder that weighs *maybe* 300lbs that can produce 6 cylinder torque while keeping 4 cylinder revability, the heavyweight I6 may not be the *best* roadracer out there, but certainly gets the job done!!

 

So, I'm kinda split on this one. On one hand you have less weight and better weight distribution at a higher cost and much higher install effort, and on the other hand you have an awesome and reliable powerplant that you can basically drop right in for a fairly cheap cost, but at the cost of weight distrubution and actually adding weight to the car (not alot, but to some people every single pound makes a difference).

 

This is probably a neverending debate that people will continue until all of our Z's have been converted to electric and we have to lug around 500lbs of batteries (or a small thermonuclear device).

[Guest Anonymous]

I think the smartest thing to do is target the class of roadracing you plan to race and then stroll around and see what they're running and whats competitive, also what about the rules? Weights, whats allowed, or are you just talking race days for clubs and stuff? At least thats how I'd do it if I were thinking of racing it.

Cheapest route, I agree with the above, a 280zxt motor.

 

Regards,

 

Lone

[awd92gsx]

Lone,

 

Hey...am I reading you right? You're in AZ now?

[ImportRacer]

I would build the car first then see what class I could race in. Im just wanting to know what you would think would make the best roadrace engine in a Z, not cheapest. I also said 290rwho would NOT be enough So that rules out the ZX motor. Im also talking about swap that you guys know have been done and are do-able. Any one seen the 3SGTE swap in a 240? You might be able to fit the alltrac drivetrain in the 240 and have an AWD Z as well... Thats something to think about.

[ImportRacer]

What would be the best engine, in your opinion, to swap into a 240Z for a roadrace application? Were not talking unlimited funds or anything so nothing to hard core. And im not talking about a dinky Auto-x car, Im talking about straight up roadracing, GT2 style and so on. In short, a car that makes more than 290rwhp. My best engines would be, 7MGTE, 1JZ/2JZ, or an RB engine maybe SR20DET. Ive also thought about some toyota V8's with aftermarket turbos on them but dont know if they woul weigh to much for a practical roadrace car. So whats yall input? Agree on these engines? Any you would like to add? How easy are the swaps with these engines?

[Tim240z]

3 rotor TT

[awd92gsx]

I've seen plenty of 4G63 swaps done into Starions and Conquests...so I don't think swapping one into a Z would be anymore difficult.

 

An early 4G63 bottom end will support over 500hp. There are many 11 second DSM's that have never pulled a valve cover off.

[fl327]

i always think that the best motor for a roadrace is the most you can get away with in your class.

depending on displacement liimits and if you can swap in a different motor from diff manufacturer.

if your limited to three liters or so i would just go l28 or l28et if they would let me, and if i could use any motor i would either go busch national 3.8v6 with a t10 in jtr configuration, and a million different motors there are a lot to pick from.

[Guest Azel]

I'll echo awd92gsx's comments about the l28et. I have one in my Z and the first thing that comes to mind is the heft of this engine. Don't be fooled, this is a very heavy engine. Comparing the weight of the l28 with the V6 in my astro van, there was at least 100lb. difference if not more. Also, the shape and positioning of the engine is not ideal for a supreme handling machine. The engine is long, is a few inches away from the firewall and is a fairly tall engine.

 

If I were to compete in roadracing, I'd do a lightweight four-banger swap. A few engines come to mind, along with the above-mentioned 3SGTE and SR20DET, there's also the GM Quad 4, CA18DET, 22R and the frankenstein Mitsu motor AWD92gsx recommends would be very nice. But I wouldn't just stop at the engine swap, I'd also swap out the 240z's rear suspension with the 240sx's multi-link suspension.

[Guest Azel]

Originally posted by ImportRacer:

So far I think I like the sound of the 3SGTE engine the best and the SR20DET just because its a nissan engine and it would be cool to keep the Z in the nissan blood line.

Uh oh.... I'm expecting Pete to jump all over you in a second...

 

I'd actually prefer the CA18DET because it mates to the 240sx 5-speed without a fuss.

 

Seriously though, I'm a Nissan die-hard fanatic but an equal-opportunity enthusiast. I don't know much about the Eclipse motor other than it is one of, if not, THE most robust 4-banger out there.

 

AWD92GSX brings up an interesting discussion about the hybrid Mitsu motor though. If the DOHC 4g63 head works with the 2.4L block then that would be a killer engine. How capable is the 2.4L block? Is it anywhere near as strong as the 4G63? How about the headgasket? I'm assuming they aren't interchangeable and that you'd have to have one fabricated? Another concern is the compression ratio, what would the end CR be? Last but not least doesn't the 63 have oil squirters under the pistons ala VG30DETT? How do you plan to incorporate these into the '64 block? Sorry about all the questions but your swap sounds VERY VERY interesting. At this point the only thing that concerns me is the custom stuff, forged pistons, rods and headgasket. Keep us informed, sounds like you're making one helluva hybrid motor for that hybridZ of yours, good luck!

 

BTW, good looking Z u got there.

[ImportRacer]

To clear up my last post, the 3SGTE and SR20DET would be my choices for 4cyl. swaps. But it seems a 4cyl. engine would be best for a roadracing application. The 4G63/4 swap sounds very interesting. IMHO if you could swap out the AWD drivetrain from a GSX/VR4/TSi and put it in a Z that would nice. If you cant tell im a AWD fan

[ZROSSA]

You may have to look a little further into the kind of tracks you will run at. A turbo car will go better on tracks that are more open with lomg straights to open it up on. A n/a motor will be better on a tighter track. Th f1 guys said that they needed 20% more power from a turbo car to keep up with a n/a one. No doubt the turbo is faster in a straigt line but the lap times would be the same because the n/a car would be better throught the corners and faster out of them.

 

Douglas