My rolling road results - Turbo VS N.A

The Car:


Here as a N/A engine with selfmade 4-2-1 header and 63,5mm exhaust, straight trough mufflers and 38 eeit carb


Here are both results. Turbo only 0.5Bar - 8Psi Boost


And here the other result with only 0.5Bar - 8Psi Boost


Most people don't want to belive that the N/A Car had real the 204Nm tourqe.
But this was not impossible. The car feels just like it has that amount of tourqe at this rpm range.

We tried 3-4 times on the rolling road and it never made under 200Nm peak tourqe.

Than we tried other cars like a Renault Clio RS, Ford Focus RS, or Honda Integra V-Tec.

Not even the V-Tec or Renault Clio RS reached the 200Nm.

Than we made another run with the capri and the results was clear:
over 200nm at 3300rpm.

don't know why it was so high. but maybe I had luck with my self build exhaust.

now compared to the turbo, both engines runs well. But as the N/A produced no more power over 4000rpm,
the turbo kicks in there and revs up to 6500rpm.

It just feels like an N/A car but it is a turbocharged car.

Not very much HP, but I will try more boost soon.
At 1.0Bar I should see a 250Hp
and at 1.2Bar 280Hp could be possible.

But for this level I must use stronger head gasket.

Weight and HP of the Car ratio should be under 3kg/1hp soon.

Good work and nice looking capri!

3kg/1hp is really much, how much is the weight of your Capri?

I use a lot of glass fibre parts. For example the front parts, the trunk or the rear windows.
It is also good because there will be no rust anymore.

I also use aluminium pipes for the exhaust system.

The next Step are a fibreglass Doors and a leightweight battery.

The cars weight is now 930kg with driver and fuel. My goal is 900kg and 300hp.


Still goes very fast. Today I run race fuel with 102 octane and with more boost.
I get 1Bar (14-15psi) Boost now and rev the Car up to 7000rpm+, which is pretty much for a pinto with original pistons and original crank

I think it produce now around 240-260hp.

Raced against Lancer Evolution 7 with around 320Hp.
From 0-200 km/h the Capri was in front. The driver of the Evo was surprised about that and I was happy
my gearbox ends at 200km/h xD because short rear differential. 4.11

It delivers more power the more I reved the car. As you can see on the dynograph. But this was a run with only 8Psi.

But the engine / turbo wants more!  More boost and more rpm. I should build a better engine with forged pistons and with a good crank and good head gasket. group A gasket will do it fine I think.

Easy way to get more topspeed is to change rear axle ratio. I assume you are using still atlas axle?
I am using 3.09 and type 9 gearbox, topspeed is 250-255km/h
If you want more topspeed 3.44 might be good choise for you, there is also ratios of 3.75 and 3.22, though same ratios are hard to find... especially 3.22 and new 3.09 ratios.

Edit: My engines max rev. is 6100 and that gave me topspeed of 198km/h and 4th gear (straight)