Its been nearly 3 years that I have started my exploits with my Honda City Vtec and it has come a long way now.
My goal initially was to stretch and see what best I could get from the stock Internals keeping most of my learnings in analyzing the efficiency of the stock components with very minimal yet effective mods. Target was to design the most efficient exhaust system in business, switch to a JDM intake manifold, self tune ECU, install full coilovers, get the maximum efficiency from the cylinder head etc.
All this helped the car to clock 100kph in under 7.5secs with the OEM gearbox as well. And with a standing quarter mile time of 15.48secs. Basically a full OEM engine.
Next step was to take the car to the next level, yet maintaining good driveability and reliability as equal to stock.
With the next level of tweeks, yet maintaining the stock bottom half (stock pistons) with the same 130000kms on the odo, I finally pulled a 6.32secs to 100kph. With a standing quarter well under 15 secs. The setup even returned once a best of 14.4kmpl and around 12kmpl on avg in city commute with revs below 4k. After this, it would indeed get more complex and tough, since you have to rely on those stupid naturally aspirated horses. No option to turn up boost or send some laughing gas. It gets to be a challenge.
We had now moved to a new facility and my outfit - Race Concepts was fully equipped to build race cars and street cars from ground-up. So my year long planning had finally come to shape over the last 2 months. Found some time from our National championship races and with a lot of learning from our Indian Touring car - Super Saloon - Honda Vtec, it was time to take this SOHC chariot to a new level for street. Again maintaining street levels of reliability, economy and all the power.
The scene in Bangalore has been growing offlate with a lot of Turbo cars coming out in various forms and sizes. So my NA plans had to be good, to keep things in perspective. The build started and I did a complete strip down of the underpinnings and braking system. And other drivetrain components. Started by replacing all the critical rubber components, bushes, bearings, lower-arms and then went in, my 2nd set of coilovers which were a huge improvement over the previous one. This takes the car to a new level and anyone who has experienced the new setup will vouch for it. A custom built 3 way system.
Upgraded my all 4-disc setup with better rotors and pads. Cleaned up the entire engine bay painfully, replaced all hoses with silicon SAMCO ones. Switched brake lines to braided ones and also added custom lower braces to improve handling further.
Then came in the engine part. The engine had to grow bigger, so a very brave-hearted oversizing was done. The 1493cc engine was pushed by nearly 80cc. And it was indeed a one-off. The whole process of blocking, decking and setting in the custom pistons was fun. After the puzzle was solved, I then shifted focus to the cylinder head. Something which I consider quite divine and therefore is the most time-consuming for me. So after nearly 11 days of hard work, it was all set to go in. The cylinder head had to flow quite well for my greedy 9000rpm target, so all that it took, went in the order.
The camshaft still remained unchanged from my previous 6.3secs setup. With a new radical manifold, high flow CNC machined custom throttlebody, high flow injectors, racing fuel pump etc in place, the engine was nearly done. Then was the gearbox. I had to do something about all those heavy spins and torque steer. So there went in, a very expensive Quaife LSD, custom close ratio 3,4,5 dog ratios (not the MFactory junk) and a matching final drive.
A very radical exhaust system was painstakingly built in about 5 days. And a lot of other stuffs went it.
A 6-puck race clutch with the right flywheel weight was in place to help the engine put all the power down. The OHC engine mounts really start to act up when you start pushing the engine. So the mounts were filled with PU and reinforced to take all the beating, yet offering decent engine damping.
Driveshafts were replaced with OEM Honda part and wheels were Enkei RPF01 shod with 205 BFGs.
Then I got to the interior. Installed an NA Apexi Timer, A race button starter, AEM UEGO controller, AEM wideband controller, real Aircraft flick switches for other controls etc. Other interior goodies - BRIDE Cuga Carbon Fibre edition seats, Steering wheel - brand new OEM Honda Momo picked from the Integra DC2 Type R, Spoon short shifter, Skunk2 Gear knob, 3D floor mats etc. The replaced the Headlamp and tail lights with OEM parts.
Engine management is RD 0901 for now, also in parallel runs the AEM Standalone which will be setup over a few weeks. The maps are far from being fine-tuned to perfection.
So finally after a grueling 60-70 days with the car and every other detail which I cant even remember off my head, it was time to crank it up and see if its all as per my plan. Topped up fluids and with the startup map, the car cranked up in the first attempt. After which, it was straight run-in. After clocking about 250kms, I could no longer find time to finish the rest. So a Honda meet was announced and I decided to take the car out in its first outing after the crazy build. It was indeed a big gamble I took, but I was very sure of what I had built. With a clutch barely run-in and with an engine that has hardly clocked anything since inception, it was a bit early to cook, but I could not resist.
So we went out that night and had a lot of fun. With a few bursts and granny shifts to keep the clutch in check. After clocking another 100kms during the drive, I decided to see what it would really feel like. And I was impressed. It was bullet proof, could take all the abuse till a screaming 8900rpm limiter and felt nothing close to what my 6.3 secs engine was. This was something else. A few other members also drove and their expressions were worth watching.
The following week was another hang-out meet and we all drove out again. And I really wanted to see what this could do. My target was to hit under 6 secs and enter the glorious 5 secs marker with a street car that weighs 960 kilos. Which is a big leap for an NA car, in full street trim with even a spare wheel and tool kit . Even a DC2 Type R with a B18 and nearly 200 horses @ 8500revs would stay away. And I have personally experienced a B18 Type R to know what that madness is all about.
So, the car still has a lot of limitations. The intake system is still not optimised for the engine tune, just a make shift setup for now, untill I find some time to work on the final setup. Engine tune is still a long way to do and was honestly a bit conservative.
Yet, managed to hit the ton in the mid 5 secs range. The car now has some serious torque right off idle and does not stop flowing untill the 9k limiter. A real blast to feel what an NA Honda should really feel like. Sounds more like a superbike, than a car. The thunderous exhaust note is an expression of pure anger and rage. The new suspension setup has taken the handling to a whole new level. Very impressive and the whole driving experience is something I cherish everytime.
I have got very close to my NA goals and its really pleasing to see the car surprising the Turbo lovers and cars.
With a lot of refinement in place and a lot more engineering planned, its going to be very interesting.
The car has a lot more ponies to come out to really shine in its full glory.
Very surprisingly its already making over twice the power of a stock Honda Vtec, at the wheels, on our Bangalore Dyno, which is very encouraging with torque curves to surprise the oil burners. And there is a long way to go.
This car has taken me to a whole new thinking level and my attachments are very personal. This is my way of returning favours. Its indeed going to be much harder for me to get every little power now, but thats the whole challenge of going NA. It teaches you a lot and takes things to a whole new perspective. Boosting is so much easier in comparision. The engineering complexity of a Naturally Aspirated engine is what makes it an engineer's favourite.
Visually I have chosen to maintain the very un-suspecting looks of the stock car. A total sleeper in my context. The only give-away are those non OEM Enkei Wheels. When I look back at how I started with this car 3 years ago with a piddly saving to purchase one, I sure have come a long way and its very full-filling!
Current Specs : Engine - - Pistons - Custom forged - made to order
- Connecting rods - Steel forged custom
- Bolts - ARP
- Block - custom cylinder sleeves
- High ratio racing oil pump
- Custom cylinder head gasket
- Fully tweeked - Stage 4 spec cylinder head
- Custom grind camshaft
- AEM adjustable camshaft pulley
- Gates Racing timing belt
- Racing valve oil seals
- Racing valve springs and retainers
- Stock crankshaft
- Custom Intake system
- CNC cut custom throttlebody
- Custom Exhaust system with radical dimensions - Designed and built inhouse - Race Concepts
- SAMCO silicon engine hoses
- Etc
Transmission - - Quaife Helical tarmac LSD - 45mm
- Custom close ratio - Straight cut - Race Concepts
- Shorter final drive - Race Concepts
Engine management and fuelling - - Currently running on RD0901
- Racing fuel pump
- Oversized high impedence injectors
- Turbosmart FPR
Braking and Handling - - Custom 3-way adjustable coilovers - Race Concepts
- All 4 discs with balanced brake splitter
- Hawk Racing pads with uprated higher grade rotors
- Enkei RPF01 forged wheels
- Bridgestone 205 G-Sport
- Custom lower car braces for front and rear
- Ultra Racing front and rear strut braces
- Steel braided hoses - all around
Interiors - - Bride Cuga Carbon Fibre racing seats
- Honda Integra DC2 Type R, OEM Momo Steering wheel with OEM Honda boss
- 3D floor mats
- Spoon short shifter
- Skunk2 Gear knob
- Apexi NA timer
- Race button starter
- AEM UEGO controller
- AEM Wideband display
Performance - - 0-100kph - mid 5 secs range with a fully loaded car
- 0-400mtrs - Anywhere in the 14 secs range. Will soon progress to the 13 sec range.
- Horsepower at wheel - Over twice of stock, as per the last dyno log. This is the first attempt and a lot of refinement is planned.
This project is constantly evolving. With the car delivering so much promise in its first full NA build, the next levels will be very very interesting.
Cheers,
Joel