TWiR 1986 S3 TWR

[KiwiDave]

HaHa Is your brain hurting? We've got 165 and approx 133 at the wheels. So it's only 5 BHP over the nikki but it's about how the SU uses what is available and delivers it that transforms the car. It is such a difference! Think of the SU as a sports carburettor. I guess it just processes everything in a different way. But I do understand why the SU upgrade had it's reputation back in the day.

[ian65]

got it now ... the more basic the better for me! I get that about the power delivery rather than out and out power... it's the same with the Elford, not loads of BHP but really wakes up the car once it's on the boost, I really notice the difference when driving Gus which just doesn't have that top end speed and torque the same as the Elford.

[myatt1972]

Great news Dave, nothing better than a noticeable differance to put a smile on your face.
You know what youve got to do now though Dave get an IDA and do it all again Would be great to have that comparison

[KiwiDave]

got it now ... the more basic the better for me! I get that about the power delivery rather than out and out power... it's the same with the Elford, not loads of BHP but really wakes up the car once it's on the boost, I really notice the difference when driving Gus which just doesn't have that top end speed and torque the same as the Elford.

I was somewhat bewildered after the first test some time ago. I could feel the shift in performance but it didn't equate to horsepower and I couldn't get my head around it. It's taken some time spent talking with guys that really understand how the process works and also seeing the power curve broken down to several pages of numbers on a screen to really see what has happened. The guys at Northampton Motorsport were really helpful.

'Waking the car up' is exactly how I would sum up to end result.

[KiwiDave]

You know what youve got to do now though Dave get an IDA and do it all again Would be great to have that comparison

Ahh, the elephant in the room. You just HAD to bring that up I've been thinking exactly the same thing Keith. In fact, it was the final topic of discussion before I left Northampton Motorsport. They stock some very tasty Weber equipment.

It's in the future plans folder for sure although I'd probably have to sell the SU setup to fund it and I'm not sure I want to do that! And then there's the DCOE vs IDA conversation plus there's now an EFi option

[Hobbawobba]

Oooo EFI you say?

Completely different. But the drivability of my current 13bt setup is really surprising. Pottering around the city centre in a 400rwhp big turbo street port sounds a bit rubbish. But EFI with a good tune is really quite surprising!

[KiwiDave]

got it now ... the more basic the better for me! I get that about the power delivery rather than out and out power... it's the same with the Elford, not loads of BHP but really wakes up the car once it's on the boost, I really notice the difference when driving Gus which just doesn't have that top end speed and torque the same as the Elford.

Turbocharging is great for the torque curve as well

[gt_james]

IDAs - good power but drive crap for most people! Although I'm sure with enough effort on setting them up properly with playing around with emulsion tubes etc they can drive well. Mostly they are a racing carb and work well WOT but not so well around town I dailyed mine with a 13B and 48IDA, and theres way more power than a 12A on a nikki, but around town it was a pain, but then I never properly tuned it. Would be great to compare Nikki, modded nikki with mech secondaries, IDA, DCOE, SUs, Elford turbo and also the rotary engineering dual DCD set up! plenty of options to wake up stock 12As. I've seen some custom twin 44 idf set ups too which look interesting and supposedly drive nicely and offer more power than an IDA.

EFI is cheating

[KiwiDave]

Got some plans for winter mods to get the most out of the SU's.

# upgrade plug wires and coils

# swap out or modify the carb throttle discs to restore engine braking (what there is of it) on overrun.

# introduce a stub stack inside the air filter to smooth and maximise airflow into the carb.

# upgrade air filters (removal of the K&N clone filters was worth +5 bhp on the dyno)

Found a nice set of plug wires.






Formula Power / 10mm / Made in UK


Could have chosen black or blue but. as any fule no, red be faster

[gt_james]

Use some cable ties to tidy the leads up, you shouldn't have them touching.

https://www.hotrod.com/articles/wrenchi ... organizer/