Circuit Motorsport

Andy Jones came to me through a recommendation for someone to upgrade the engine to a twin carb set up. I don’t usually get jobs in like this, except for the set-ups already been fitted and I generally tune them on the dyno here to suit. In this case I had the opportunity to fit the set up ensuring it was fitting correctly and the linkages all worked as they should with a full range of movement. Seldom do I see set-ups arrive here that open both throttles at the same time and.../or achieve full throttle. On a vehicle like this, setting up the throttle system from the pedal through to the throttle plate is tricky, but essential. In this instance, I could make sure all was fitted correctly.
Onto the Camper van! Quite a tidy example having had an engine rebuild not long ago. Andy had some bad luck with some of the tin wear on the engine, which caused the previous engines demise. Engine now running sweet, I completed a run on the dyno to get some baseline to work from (blue). Andy had also brought with him an uprated exhaust system. After fitting I did another dyno run for comparison (red). At this point it was time to optimise the ignition timing with a final run (orange) before fitting the twin carb set up and tuning the engine for the final set-up (green).
The manifolds and carbs needed some machining for them to fit properly. But we got there. As you can see from the dyno graph, the exhaust didn’t make a huge difference. However, it allowed for more power when I optimised the ignition timing at that point. It was the twin carb set up once tuned which really made the difference. The ignition timing was once again optimised as making changes such as this drastically changes the air flow and characteristics of the engine.
Very happy with the result and how the van now drives. It’s extremely smooth and pretty grunty for this set-up. Feedback from Andy following collection was nothing short of ecstatic!
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Great to see Josh Harvey racing very hard and fast on Monday! Getting caught up in an incident early doors with another car spinning put him back in the pack, but clearly the fastest car on track and ripping the lap times makes it a very tight finish! Great driving, and looking like a super season ahead!
Jordan Curnow, also doing the business in the Saloon championship! First dry qualifying and race, and already bang on the pace with a new personal best and fighting it out in class!
Honda racing at the absolute sharp end with Circuit Motorsport! Road or race, get the tuning done right!

Great to see Jordan and his Honda Civic EP3 Type-R for an Alpha-N mapping conversion! This car runs in the Castle Combe Saloons Championship, and it had previously been tuned with Hondata, but while okay on full throttle, it struggled off throttle and with part throttle hesitations. There's a reason for this, Jordan has ITBs (individual throttle bodies), and with the original MAP sensor set-up it simply cannot work efficiently in the vacuum area. The previous tuner tried to s...et-up Alpha-N, but reverted back to MAP sensor. It's not easy, Hondata requires good understanding of how the car and ecu works, but the results make a big difference. Drivability and throttle response throughout are now instant, and we have seen some good power increases throughout with 271bhp & 171lbs/ft.
Look forward to seeing how you get on Jordan. With Harvey in Castle Combe Hot Hatch championship, we have the two front running Hondas doing the business!
If you want some real Honda tuning, normally aspirated or turbo then get in contact!
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We see such a huge variety of different cars, but that also says something... it means we can tune a huge variety of different cars!!! You may not know the Cyclone, but this is a British kit car featuring the Vauxhall C20LET engine, and when set-up right it's brutal!
A recent engine change and the car was just not performing as Steve wanted it. No problem, full diagnostics with tuning and an MOT, now it's punching harder than ever. Weighing next to nothing, a turbocharged 260bhp & 255lbs/ft really does kick you hard in the back!

I like this, you start with a base 90bhp diesel, and then you tune!
Jason has the Peugeot 206 2.0 8V HDI, it was already Stage 2 giving 125bhp (that's with the new FMIC and hybrid turbo). It's not a quick process to tune correctly, but we end up with big gains at 165bhp & 268lbs/ft. Perfect air fuel ratio giving next to no smoke. Limited by the turbo pressure maxing at 21-22psi, but all in a very nice set-up!

Congratulations to Josh Harvey on his race win in the season opening Castle Combe Hot Hatch championship. It was a very fickle weather day with qualifying in very wet conditions, but the afternoon was always going to be a last minute call as the weather improved and the track started to form a dry line!
We tuned Josh's Honda Civic EG last month with the fantastic K20 engine pushing out 269bhp & 164lbs/ft with a capped 8800rpm limiter. Awesome power and drivability from the se...t-up, and with a fastest lap already in the 1.14s, this is going to be a very hard car to beat!!
We are specialists in Honda ecu tuning, with live mapping for the P28 & P30 ecus, including turbo/supercharger set-ups. If you have Hondata then full optimsation available from the full suite with Alpha-N setups right through to big turbo builds! Let us know what you got, road or race!
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We see quite a few Minis, classics and modern! This classic featuring a SC 8-port cylinder head, cam, ITBs etc, and then an SC Delta ecu. The base was quite a bit out, so a bit of fast tuning to get the engine run in by the customer. A few weeks later we can move on to full power tuning and optimise drivability!
It's a nippy little beast, and despite the cam, it's now driving very clean all the way through to the limiter. Power is 109bhp, but a restrictive front end air filter set-up, and a slightly too small exhaust means we can get close to 115-120bhp in the future.
That's a fun Mini!

It's hard to beat an M3, but when it's this good it's really hard to beat! James has crafted this E36 3.0 by himself with a view to racing next season. Stunning attention to detail, and set to be a very competitive car.
The engine is pretty much standard other than gorgeous carbon airbox. This is designed to run without a MAF, so I convert the original Bosch ecu to run Alpha-N (TPS load), and live tune accordingly. Good gains throughout, optimising every step for an extra 1-2 lbs/ft gain and max horsepower of just about 300bhp!
Good luck next season!

Keeping with the Mini theme, it's the more recent incarnation from 2005, a breathed on 1600 supercharged Cooper JCW! A few extra engine mods see us reach 263bhp & 203lbs/ft @ 7500rpm with custom mapping and 550cc injectors. It's a very rapid Mini!
Tuned quite a few of these to high performance, get in touch if you have a supercharged Mini :)

Beautifully restored Mini 1275GT brought in from local chap Bernie Twist for an MOT this morning. Sympathetically brought up to date with an 8 port head, Jenvey throttle bodies and running on DTA engine management, this sweet little Mini passed its test with flying colours and will be back soon for tweaks to the maps. Lovely car. Credit to Bernie.

Castle Combe Circuit employee Paris popped in this morning for a power run and health check. Made decent power at 210bhp and 216ftlbs. Good job we ran it as it's running lean at peak boost and rich at the top end. So future mapping session will ensure the mini is running safe and sound again soon.

Anyone local to Castle Combe or surrounding areas interested in temporary helping out with a back log of work over the next few weeks, please message us for further information 👍

Another iconic car in for its annual MOT test. TVR Griffith 540. Certainly heard its arrival what with the roaring noise of thunder as it pulled onto the forecourt.

Iconic Honda NSX 3.2 in today for service and check over. Superb low miles car in tip top condition and also took the liberty to dyno the car and made virtually bang on the numbers. 295bhp with 222ftlbs

Another one to be saved

After setting up Deans grass track Red topped 20XE engines car, I had a tickle in the stomach and an urge to start my mk2 Astra GTE 16v for the first time in atleast 6 months. I'm always sympathetic to engines which haven't been started in a while, so I turned the engine over until oil pressure was up and then started the car. I was really impressed with it starting on the flick of the key and unlike most 20XE engines, no follower tapper noise 😜. Oh... and that glorious rasp these engines make when the throttle is blipped... 😍❤. Takes me way back!

Dean Robinson is a veteran Circuit Motors employee. He's dabbled in a few forms of motorsport, but now is competing in grass track events with this unusual Nissan micra which has been gutted and completely reworked for grass track racing. Now sporting a Vauxhall red top 20XE engine with bike carbs and DTA Fast ECU to control ignition timing, Dean asked us to set it all up which all went well. End result is 185bhp with 168ftlbs which is pretty damn good for a stock red top on ...standard cams and head. Opening up the inlet on these engines really do unleash some power. With the DTA running the throttle position sensor too, we could really get the engine set up well. The carbs were already rejected for the engine and were tuned well. We do keep stock of jets for these incase we needed to recalibrate the carbs. We look forward to Deans feedback from his first race this weekend. Good luck Dean!
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We went for first time to a Japanese car show. Found it easily. Parking not a problem. Facilities good. Seemed well organised. very good system with lights when exiting car park field are end of day, a lot less hassle then normal at large events. We had a great day and would go back again.

Transformed the car. Great guys who know their stuff.

Top workmanship, can't recommend enough

Took my 3 door Cossie there running a bit rough and not that powerful a few little tweaks it hit 400 the drive home was immense loved it will always use them

Took in a civic to be mapped and while waiting was given a loan car for the day very helpful and knowledgeable bunch of guys did an excellent job very happy and well priced!

Superb service, many thanks for fault finding and sorting the car

Sorted out my focus st really quickly, very friendly and the labour charges are spot on would really recommend to anyone.

If you want the best this is the place to go

I bought my partner a driving experience for his birthday which he used yesterday. He had an amazing time and was thrilled with the day. It was well organised, tidy and the staff were really friendly and helpful. Would definitely recommend it to others. Than you.

Had my A3 Quattro remapped yesterday got more hp and torque that I thought. Chuffed af tbh. Highly recommended :))

Great guys. Honest results and very helpful.

Can't wait to pick the car up.



Deserve more than 5/5 ��

Got me outa trouble saved my day couldn’t of asked for nicer people

Friendly and very professional! Turned up early and had things ready promptly for me to get my Skyline dyno'd straight away!