Fitting & FAQs
The parts nobody likes to print
A supercharger doesn’t fix a tired engine, it finds every weakness in one. Read this before you order, not after — it is the same list we’d give you on the phone.
You’ll need
- A healthy engine with valve timing set and checked. Compression 8.5:1 maximum.
- Twin-port heads with stock inlet manifolds. Single port works with adaptor plates, sold separately.
- An electric fuel pump and a crankcase breather — both available as options with the kit.
- A bigger bore exhaust. The stock system is too restrictive to let the gas out fast enough.
- Disc brakes. Drums behind this much extra torque are not something we’ll recommend.
- Timing set 18–24° at 3000 rpm with distributor advance disabled. Bosch 009 or a 123 ignition.
- Time on a rolling road with someone who knows the carb. Jetting is finished on the dyno, not in the post.
- A clutch that can hold it. A Kennedy Stage 1 if yours is marginal.
Don’t
- Don’t fit a kit to a weak or worn engine. It will find the weak spot.
- Don’t run E10. E5 high octane only.
- Don’t take timing past 24°, and don’t guess it.
- Don’t ignore pinking or knock — that is the engine telling you the tune is wrong.
- Don’t run lean at idle, cruise or under load. Slightly rich aids cooling under boost.
- Don’t use high heat range plugs. Low to mid, and use the ones supplied.
- Don’t assume it’s fine. Gas-analyse it at idle, cruise and acceleration.
- Don’t set off without a spare belt in the car.
The kit is designed for an engine in stock condition. Aggressive cams, raised compression and other performance work already done to the engine can mean extra parts, extra steps, or a different pulley — tell us what you’ve built and we’ll tell you straight whether it suits.
FAQs
The questions we actually get
Is it an easy kit to fit?
Mechanically, yes — everything bolts on, with no welding and no modifications to the car. A competent DIY mechanic with the instruction pack and the assembly video can do it.
Calibration is the part that takes time. Belt tension, bracket positioning and fuelling all want adjusting, and the final jetting has to be done on a rolling road under load — not at idle, because idle is not where it matters.
What will I actually gain?
A stock 1600 twin port with factory crank, cam, ignition and induction makes 40–45 bhp. With the Ultimate or Slammed on a healthy engine, expect 90–105 bhp and 160–175 Nm. The Sleeper lands at 85–90 bhp and suits 1300–1776cc.
The supercharger raises mass airflow: compressing the intake charge packs more air and fuel into the same cylinder, which raises cylinder pressure, which is torque. Higher impeller speed, higher pressure ratio, more of all of it.
How much air is an AMR 500 actually moving?
Half a litre per revolution — that is what the 500 in the name means. At 10,000 rpm that is roughly 5,000 litres a minute of theoretical airflow before efficiency losses, and the unit is happy to about 16,000 rpm.
Practically that puts it at home on 1300–2000cc. It will run on bigger, but boost falls away as displacement climbs because the engine is asking for more air than the blower makes.
Can the boost be changed?
Yes — a smaller supercharger pulley spins the impeller faster and raises boost. The pulley we supply is chosen for your stated displacement, and up to 1641cc that is around 8 psi. Bigger engines see less from the same pulley.
Before you go chasing more, check the rest of the engine can take it: compression 7.5:1–8.5:1 for 8–10 psi, fuel system up to the flow, and an ignition curve that isn’t going to detonate. Monitor it continuously.
Will my clutch and brakes cope?
A marginal clutch will slip under this much extra torque. Assess it honestly before you fit — a Kennedy Stage 1 is the one we recommend for moderate boost.
Brakes matter more. We strongly advise against running a boosted engine on drums; a disc conversion or equivalent is the right call for stopping distance and for heat.
What’s a sidedraught carburettor, and why a Weber?
A carburettor mixes air and fuel in the right ratio before it reaches the cylinder — standard equipment on almost everything built before the 1980s. The Weber DCOE twin-throat sidedraught is the performance one: a wide range of chokes and jets that are easy to swap.
A 40 DCOE tunes happily from 1500 to 2000cc. Every engine behaves differently, so pump rod length, pump jet size and spill jet are all things you may end up adjusting to get the shot right off idle.
What isn’t in the box?
Electric fuel pump and crankcase breather are optional extras rather than standard. Exhaust parts are not included at all, and neither are heat riser blanking plates or gaskets. Single-port engines need adaptor manifolds, sold separately.
If your engine has been converted to twin carburettors, you’ll need to put the stock twin-port inlet manifolds back on to fit the kit.