Chapter 7 with a Caterham SVT

[redursidae]

Thank you all for the warm welcome and answering questions on my first post. I've learned much about the car thanks to your help and reading around the forum.

 

The story with this Caterham started after a fantastic 2 day trip to Arroyo Seco Raceway in January where I met Josh from Rocky Mountain Caterham, Nathan Down, and 4 Caterham owners that were very welcoming to me hanging about. It was a very special weekend to say the least. After the trip I knew it was time for a se7en and the Chief Financial Officer didn't object too harshly to the idea. But wasn't sure how or when to make it happen. I was interested in MK Sportscars with Miata components because I know Miatas well and were within my budget, but a few days later I get a text:

 

Quote

At a birthday party thing last night I encountered a guy who is selling his Caterham. And his trailer. He's emailing all specifics to me. What's your email?

I went to look at it with friends, and seemed like the right fit. Much man math later, one car sold, and I was able to bring the Caterham home.

 

 

 

It is a 2006 Caterham SV with the Ford Focus SVT engine. Has regular floors, adjustable Bilstein dampers, 15x6.5 wheels and 195/50/15 R888R tires, Raceline wet sump, and had 1335 miles on the odometer. I don't know where it was built or whether it has an LSD. The previous owner did not drive it on the road much and most of the 800-900 miles he put on it are track and autocross miles. It is well broken in  
 

I've spent the last month getting acquainted with the car, catching up on maintenance and definitely not plotting mods. Some items addressed so far have been to install the headlights, fix a couple of issues with the tail lights, a quick ride height adjustment, replaced the timing belt and a fresh oil change. The front ride height was too low before, at 130mm and 25mm rake. It's now 140mm front and still 25mm rake. More adjustments, an alignment and corner balancing are needed. The timing belt was original from 2002 and I did not feel comfortable driving with it, even though it looked ok. Also put fresh spark plugs to have a baseline.

 

 

 

The plastic end-tanks in the radiator were leaking, so ordered a new aluminum radiator. A few "while I'm in there" happened and I swapped all the clamps for some without hose-eating slots and replaced a heater hose that was cracking too. Also found that my radiator fan has the shorter style mounts, and had to get new extensions. I'm currently waiting on the extensions to arrive so I can finish the job.
 
Before the radiator job started, I did an oil change to Amsoil 5w-30, because the weekend prior I drove it through the mountains and oil pressure was right at 1bar at hot idle. A bit too low for my liking, and figured a fresh change would be a good starting point. The first drive on the new oil seemed promising but that was on a cooler day.

I have driven the car 170 miles so far. The power and torque is awesome, and definitely the fastest car I've owned. The suspension feels better after the ride height adjustments but it is still a bit stiff. The exhaust sounds good and pops a lot on decel which is growing on me. Next thing is to keep driving it to shake out the gremlins, dial in the suspension, and do an autocross and trackday to find what to do next.

 

But I do have a wishlist for once I have the Miata's engine finished:

- 13 inch Apollo wheels + Nova tires (wet sump clearance is a concern though)
- Soft Bits for Sevens Half Hood
- Aero screen
- New belts
- Tillett seats
- Trackday roll cage
- Standalone ECU still to be decided (Leaning Haltech or Link G4X)
- Borla Induction or AT Power ITBs

 

But overall very happy, and glad to have finally joined the se7en community

[redursidae]

One more picture taken by my friend in our first blat together

 

[Austin David]

NICE.  Have you figured out if it's an LSD yet?  ;-)

[redursidae]

HA no, not yet. I’m still building condidence with it. It did very well in some hairpins in that mountain drive, so that’s promising.

[Austin David]

put one wheel in sand and goose it.  you'll know pretty quick.

 

I got ITBs from AT power, they're fantastic.  Double-check the "pull" direction for the throttle hookup!  I had to put in a new ECU, which was a /project/ but the outcome is fantastic.  If you're gettin 13" wheels, consider 13x8 in the back.  They look better, and once you get those ITBs tuned it'll help.

[redursidae]

Just saw your build thread and went for a read. Very good information, thank you. Seems you were able to resolve all the issues with the ME and trigger issues? Any chance you could take a video of the sounds with the ITBs? For science of course.

 

I will consider 8s in the rear, maybe with 215s instead of 245s. The biggest worry will be ground clearance for the wet sump, because the 13s will lower the car 1.7" if my math is mathing. The sump is merely 4" from the ground at the moment, and although I can raise it further I'm afraid of making the geometry worse.

[Austin David]

it just started raining but if your CFO is receptive to gentle nagging I highly recommend the ITB route.  My official review is "I can't believe they sell a Caterham with a single TB".  I'll try to grab some audio when I'm out next.

 

Yes, I have the ME221 running well.  It has a "spark scatter" which can drop idle a little, so cold starts are great and hot idle is great too.  If you do go the "new ECU" route I can't stress enough the value of the CAN gauge.  I can keep AFR, TPS, RPM, and trim all on the screen at once so I can watch the tune even if the laptop is not around.

 

I have a wet sump.  It has touched a few things but not super hard -- always speed bumps.  Squirrels and stuff aren't a problem.  I would prefer more clearance, but I also like not touching my brake for right turns so ...

Edited April 3 by Austin David

[JohnCh]

I love the license plate!

 

An easy way -- or so I'm told -- to check if you have a (working) LSD is to raise one rear tire off the ground and rotate it by hand. If there is some resistance, you either have a plate type or torque biasing LSD. To check which type, raise both wheels off the ground and again rotate a wheel. If the other wheel rotates in the same direction, then you have a plate type. If it rotates in the opposite direction, then the PO probably installed a Quaife. 

 

I can second the value of a CAN gauge. I'm running an AiM display in my car and have a screen set up that includes Lambda and TPS. It's really useful when evaluating the map for drivability. Not as good as logging, but if something seems awry on a drive, you can quickly evaluate where it's happening without plugging in a laptop. As for the sound of ITBs. Yes!  I have Jenveys sticking out of the bonnet. The sound is great, albeit rather loud. Having gone through a few different cam configurations over the years on a 2.0L Duratec and now a 2.4L Duratec, you can really hear the difference between cams with the ITBs. The more aggressive the profile, the louder and angrier the sound.

[Austin David]

If you have clutches you'll know it on every turn, clunk clunk clunk

[JohnCh]

2 minutes ago, Austin David said:

If you have clutches you'll know it on every turn, clunk clunk clunk

 

Assuming it is still effective after all those miles, hence my parenthetical "working" proviso. 

[Austin David]

my understanding is the clunk tells you it's working!  it's the "everything is OK" alarm.  17k miles, still as loud as ever

[KnifeySpoony]

Yep, if you lose preload, I would expect things to go silent.

[Slonie]

Glad to hear you're enjoying the car! You probably noticed, but since you were thinking of swapping—there's a set of Apollos for sale on the forum right now...

 

[Austin David]

On 4/3/2026 at 11:02 AM, redursidae said:

Any chance you could take a video of the sounds with the ITBs? For science of course

 

Traffic was trafficky but I did get some representative noises for you.  The first one is from a stop and less cluttered with wind noise.  For all these my phone was in the cockpit and got decent audio without being overwhelmed with wind and LSD clunking.

 

https://youtube.com/shorts/axEG7ke-TZw

 

https://youtube.com/shorts/QmZrpB6WMS8

 

https://youtube.com/shorts/e78X_kXYZ2s

 

WOT at 7k+ in 3rd is something to behold.  I'm not sure I have equipment capable of capturing that experience.

 

My intake is on the left about 4' from my face, I dunno how much difference that would make.  When there's a jersey barrier on my side I can hear the valves, on the right I can hear the exhaust.

 

In fairness to my LSD I only really notice in parking lots.  Once there's any throttle or speed it falls below the noise.  BUT! It carries perfectly through a GoPro mounted to the roll bar.

 

All this is to say you should really be working on your CFO to plan this project.  In order, I'd do aero screen, ITBs, 13" wheels, then the half hood.  Also double check the 13 profile, I didn't think they were so much shorter.  You get a lot more sidewall, which (I am told) makes for a smoother ride.  If you need I could attempt to measure my clearance at the sump but it's probably under 4".

Edited Saturday at 05:08 PM by Austin David

[JohnCh]

The audio on this one is pretty good. Never get to full throttle due to traction issues but running to 8k rpm. 

 

 

@Austin David if you remove the additional tracking info from the youtube URLs (after the ?), videos will embed.

[Austin David]

I didn't want them embedded - the editor asked me.  WOT is hard to record on public roads, it's a very short lived event

[KnifeySpoony]

Here is a vid of my car on track (let a youtuber review it). Very representative of what the car sounds like when driving. Unless there's a wall to my right, i don't really hear the exhaust at all, it's all intake honk. The microphone is on the center console fwiw.

 

 

[redursidae]

Thank you all for the comments and ear-candy!

Officially it has an LSD by the "goose it and find out" method. I went out on a drive yesterday to test the fan install and make sure the coolant level was good. The fan extensions hadn't arrived, but because I wanted to take it to Cars and Coffee with friends today I ended up using zip-ties like it gets done on oil coolers. Held up well yesterday and today. Also no drama with the radiator, and the oil pressure has continued to hold up with the fresh Amsoil. But I did shake a few gremlins loose, and it seems to have a fuel leak near the tank. From what I can tell it seems to be the filler hose is cracked, so I'll work on that this week. Also found out the fuel pump is on the side of the tank? That's a first for me.

 

Signed up for autocross on April 18th. By then I'm planning to re-adjust the ride-height to have the proper rake, verify the corner balance, do a bolt-check and fix that fuel leak. The car seems happy otherwise.

 

@Austin David The CFO approves of my plans, but it has to wait due to the engine build in the Miata still taking place. I want to keep a fun car drivable as much as possible too. I've been sold on ITBs for a long time, and have owned an ITB car for a few years now, so yes it's only a matter of time on this one. Thanks for sharing the audio clips. I know videos rarely do justice to these induction noises at part throttle, but I do enjoy hearing the differences as the RPMs and throttle angles change.

 

Noted on the CAN gauges. I run a CANChecked in the Miata's dash (replaces the dummy oil pressure gauge) that is feed by the Link G4X. I'm a big fan of it as well because it fits cleanly and shows all the information I need. Once a standalone gets installed it will go with a CAN gauge as well.

 

7 hours ago, JohnCh said:

The audio on this one is pretty good. Never get to full throttle due to traction issues but running to 8k rpm. 

That is glorious! Thanks for sharing.

 

On 4/3/2026 at 3:26 PM, Slonie said:

Glad to hear you're enjoying the car! You probably noticed, but since you were thinking of swapping—there's a set of Apollos for sale on the forum right now...

I missed out on these unfortunately. That's ok, I'll keep looking.

 

6 hours ago, KnifeySpoony said:

Here is a vid of my car on track (let a youtuber review it). Very representative of what the car sounds like when driving. Unless there's a wall to my right, i don't really hear the exhaust at all, it's all intake honk. The microphone is on the center console fwiw.

Very nice! I've seen this video before and really enjoyed it. Cool to know you're around here. Is your steering as heavy as he says?

[KnifeySpoony]

Yes it is heavy but i like it. Not an issue for me but everyone who drives the car comments on it. 

[redursidae]

Some details of the radiator replacement in case it helps others.

 

Initially the car had this setup. Older K series radiator:

 

there was a tee between the header tank and the radiator between the fan switch and upper radiator hose. The line goes to the back of the head to a plastic manifold where it joins the upper radiator hose.

 

The new radiator was missing the provision for this tee portion, and with approval from Josh I deleted it and ran only the line from the back of the engine

 

The next hurdle was mounting the fan. Josh indicated it seemed to have the older mounting solution, with short legs in the fan and I needed extensions and some new bolts and nylocs. Easy enough.

the extensions look like so, and after cutting/filing the boss at the right side all fit together.

 

Then used some M6x1.0 12mm long bolts with M6 nylocs to get it fastened.

 

 

Need to go test drive this new setup but I don’t see why it would have any issue.

 

 

Im expecting a replacement filler hose to arrive today to hopefully fix the fuel leak!