Geoff I got word 190bhp atw is in a Finnish recent class winning 510
It is only 1800cc and spinning well beyond the SR20VE usual redline.

I takes alot of $$$ to get there but yes its possible, however from
the data out there it seems the sr16ve is the choice engine for many
who want the extra revs on the track with light car.

Hi Tom,

These are some figures from my Dyno.

-SR20DE STD(Pulsar Challenge cars, standard ECU, wiring AFM etc) 125-135Hp atw at 6900rpm

-SR16VE N1 STD 130-140 Hp atw at 8400Rpm

-SR20VE Built for Circuit 200Hp atw at 8200rpm

-A12 STD Long motor and inlet manifold. Budget single injector EFI conversion, log turbo manifold. -180Hp atw


The best 2Lts engines in Australia make 240Hp atw and these include Honda K and B series, 3SGE and SR20VE, with the SR20VE being slightly higher than the others.



I would not recommend a belt driven supercharger on a circuit car unless it was used for Auto X or motokana.

The Turbocharged standard A12 makes more power than all the Standard 2Lts engine options and is lighter. But you would have to balance up the fabrication time differences between fitting an SR and making the bits for the turbo A12. Both options will need new Exhausts, wiring, fuel systems, upgraded cooling systems etc.

I like the idea of you going with a low boosted stock A12 to start with. You will get away with the gearbox and tail shaft you are currently running. You wont need to run an intercooler at low boost and the radiator you have may be up to the task.

The car will still be light and balanced with little increase in weight over the front. The value of this should not be underestimated.

If the standard cam is retarded about 4-8 degrees, Peak power will be at around 72000Rpm and less boost will be require to make the power(taking the stress off the gearbox and clutch).

This combo running 15Psi and E85 will make 140-150Hp atw and wont need an intercooler. It would be a faster car(even initially) than having an SR in there making more power.

The other advantage is that extra power can be added as clutches and gearboxes are upgraded and an IC added over the years, with the potential to make more power than ANY NA 2 Lts can make.

I like that the A12 Budget turbo makes more power than the Standard 2-ltrs.

I'm still on computer design of the A12H crossflow head, but in the mean time I am going to be beefing up my A12 to a turbo setup, and can make double of the EFI Items for this setup Tom. The new head is going to take a while longer than it would to make a really nice EFI-Turbo A-series.

That sr16ve figure likely the early version
which correlates to 175hp factory ate.
N1 version is 197hp so produces more atw.

late Sr20ve seems the winner as getting a craftman
these days to make anything for an a12 is hard.

The SR20ve could theoretically run just with
a reversed throttle body and factory ecu.

That seems easier than making/getting all bits
required and tuning for a turbo A12.

The Sr20ve like the Sr16ve has a few models that
make less power so have to choose wisely.

Some people also put the turbo sr20ve cams into
the NA version. The cream of the crop 20ve is the
one with the square rocker cover not rounded.

As you push for more on any turbo engine the box
becomes the expensive factor as well. The shorter
ratio gearset is like 2k aud alone before install
for the Nissan boxes.

A good VE site and jeesh the VE sound awesome as well
almost like a 10k rpm FIA but different.
http://www.sr20ve.jordanwhitemusic.com

Matt, PM me with details.

Simon thank you so much for sharing the information; I do have a 63 series box as a spare to ther 60 series box in the car. I also have a A12A that's been freshly rebuilt. At what power level did you have to go to forged pistons? Also is there a reason you don't like belt driven supercharges on a track car?

I already have the Formula 500 auto X car which there is now way a 1200 could ever compete with 345KG 100hp single seater.............so I don't think Maliki the 1200 auto-x focused would turn out well.

Hi Tom,
I have never had a failure using cast pistons, but changed to forged as a precaution once I was consistently making over 220Hp atw. I have done a few pulls on the dyno at over 30psi on cast pistons, but wouldn’t want to run at that boost over a race with the std pistons in it.
The fresh A12 will be fine for boost. Though I do like to run about .018” (.006/1” of bore diam)ring end gap when turbocharging an A12. For 15Psi you will get away with a tighter ring end gap than that.
Is the A12a all standard? ie, round port head, cam, springs etc.

Do you have acces to a workshop and a eddy current dyno?

Regarding the belt driven option, Unless it’s a later screw charger, they are not as efficient. The drive losses are also significant. Because they are positive displacement chargers they make boost from low down, which is great for the street but can be prone to detonation low down without dropping comp or pulling ign timing. Then at high rpm the losses start adding up.

I like that with turbos, you can size them to start working from higher in the rpm(say 4-4.5k), This makes them efficient at higher rpm and Boost is higher than ex manifold pressure. Also you can control boost to maintain a flat torque curve for linear power delivery within driveline limits. Eg, if your gearbox is rated to 150 ft lb, you can add boost until you are at 140ft lb then add more when the torque would normally fall off to maintain the 140ft lb.
So the boost could be at 16psi at 4500 back to 13psi at 5500 then tapering up to 17psi at 7500

be prepared for many hours tuning a turbo A series
specially if you are new to efi and ecus lectrics etc.

To be fair D unless you are chasing the upper limits of what is possible going the turbo way is not that scary or time consuming.
About 26 years ago I had a A14 that had a simple 'J' made from steam pipe tubing coming off a factory exhaust manifold, along with a nice log type inlet manifold with individual injectors. I used the largest T2 which came off a 1800 SSS Bluebird and an intercooler off a Mitsi Starion.
At that stage the ignition was still points and i used a very early fuel only link computer.
All very basic BUT the combination was great and after adding another single Mitsi injector just after the throttle body ( I think from memory ) and taking the boost upto around 12psi in a 110 chassis the combination ran a quarter mile in 13.7 with a top speed of 107mph- remember this was 27 odd years ago.
Also worthwhile mentioning is that I used the 63A box which worked great.
The point to all this being that even a basic and simple turbo setup will deliver excellent results and there really is no need to start dropping bigger engines in ( and all the associated changes required to make the car handle properly again ) to get what Tom is after.
I can tell you that if I didn't have the SSS I would be definitely heading the A12 turbo way and if ever one wanted inspiration, you only have to look across the Tasman and see what Simon is achieving with that amazing little coupe.
Cheers
Dave