I think I might be a good person to respond to this topic as I have had both engines in my car. Well I had a 3L L28, which wasn?t stroked, but bored out a lot to Just over 3L, revved nicely to 8000rpm, and currently I have an L28 Turbo injected.
Here are quick specs of both motors.
3L. L28????F54 block, P90 head, forged pistons, comp vale springs, 76* cam, 10.5 ? 11:1 comp ratio, ported head, Twin SUs setup correctly.
L28 Turbo ???GTR pistons, low comp 7:3 to 1, turbo custom cam, custom exhaust manifold, GT30 turbo, Autronic SMC etc.etc.
BTW?? the person who ended up buying my 3L motor raced in some class in QLD for 4 years finishing each season in top 5.
The 3L made about 103rwkw with SUs, can?t remember at what RPM, with webbers 45mm which I got later would?ve made about 130rwkw I think.
It drove very nicely even with 76* cam, as it did have 3L to help. The cam really came in hard at 4000rpm but it was still very flexible and drivable below 4000rpm as well.
The car made the best induction noise that I ever heard from a 6 cylinder. It also would spit out fumes of up to 3-4 meters as it was lumpy, and very noisy.
It made fantastic raw old school noise. I raced a 240z L24 Turbo, T28, old motec ecu ? and I just beat the car. The other car was making 102rwkw.
However with SUs and 76* cam the motor wouldn?t idle below 1300rpm, it would get about 18-20L of fuel per 100kms taking it easy. With webbers around the city fuel consumption would be much worst.
The current L28 turbo makes 220rwkw (on Racepace dyno) at around 5500rpm, redlines at 6700rpm and it makes over 200rwkw from 4000rpm.
It is much more quite than 3L, just little more driveable down low below 3000rpm, most likely due to EFI. The car makes heaps of torque as it went through 3 gear boxes in 12 months (FJ20 modified box, L28 box, 1 mixed box of parts)
All 3 boxes had 3rd gear stripped when flat sticked rolling in 3rd gear (torque gear) Now I finally got the RB25det box in, no problems since. The turbo motor is far easier to live with on daily basis and fuel consumption is great. It?s about 11.5 to 12L per 100kms, and that?s not just cruising.
The car still makes that lumpy NA L28 motor sound, but once on boost the turbo makes a bit of induction noise.
I?d never go back to a NA motor again, unless it was for historic racing or some hardcore restore job.
However it all comes town to $$$. The Turbo motor makes more than double the power of the 3L in my case, however it would cost twice as much to build. Plus on top of that if you wish to push more than 200rwkw you will need a better g.box with a new tail shaft, put in CV shafts, get a good LSD in an lower ratio ie. 3.5 or 3.7, modify fuel lines, add electric fuel pump or pumps, surge tank recommended, Once you?ve done all that you need to upgrade your brakes to get engineers certificate (another $500)
3L is better option if you are on a smaller budget or want to maintain old school look and feel etc. However if it will be carburettors (webbers or similar) you won?t want to use it on daily basis as fuel consumption will kill you. To build EFI 3L stroker with throttle bodies cost nearly as much as a turbo motor.
Once you built your 3L stroker, you?ll proudly be cruising down the street and you?ll have a P plater rock up in a 15 year old Silvia with a T28 on it that he got for $1200, kick you?re a$$ sounding like a law mower with an oversized exhaust, you might rethink you engine
P.S. I do have a friend whom has an old silvia with T28 that did 12.4@109mpg (on slicks)
The best value for money is a RB30 turbo motor as you can keep fairly stock and still get good power out of it. It?s relatively easy to install, cheap and easily available. Stock-ish motor will easily make 200rwkw with a few bits and make loads of torque.
If you feel brave and want the smoothness of a twin cam motor go RB25 which standard bottom end should be good for about 245rwkw, but will need bigger turbo. Stock turbo is good for 190rwkw max. If you feel even braver and you just sold a kidney, go for RB26 which with stock turbos will make up to 255rwkw on 15psi, but you will need cam gears and good exhaust.
I was lucky enough to get a RB26 from a friend for dirt cheap price (no turbos) going single turbo anyway, so 1 day when I get my sh!t together and put it in, I?ll be able to do the compare of the 3 motors lol
BTW ??.Gav when I took you for a spin last time, car had the old crap laggy turbo with 190rwkw, new GT30 is so much better.
P.S. I am happy to do a dyno or 1/4mile compare vs a 3L stroker??.. Quarter mile I?ve done 12.12@117.5mph on pulp fuel street 18? tyres. What?s the best time for a 3.1L stroker and with what diff ratio? I?m sure ?thehelix112? will be happy to help too He has a nice GT35R on his car.
P.S.2 This strictly for scientific and education purposes only
OMG ?? this report felt like doing home work???.. lol
