Free St/St Janspeed Manifold4/2/1 swap - worth the hassle!?

Scottd · Post by **Scottd** » Fri Jul 14, 2006 12:30 am

I might have the opportunity of swapping over my original manifold + St/St downpipe/flexi with a 4/2/1 Janspeed. Uldis had one of these once I think?? All the work would have to be done by me/people I could find who actually knew what they were doing

Is it really worth the hassle!?? It wouldn't be completely free as I'd need to buy a new lambda sensor for at least my old manifold that I'd be refitting in the donor car. Not to mention botls, gaskets, heat shields etc*.

I'm thinking atm it'd be too much work, but it's be a pretty expensive £400+? manifold upgrade for almost free*. Besides my de-catted Eliseparts exhaust was sounding a bit quiet! 'Joke' I'd probably have to put the Cat back on w a Janspeed manifold. :-\

scott

Uldis · Post by **Uldis** » Fri Jul 14, 2006 9:41 am

Aaaah, complex answer.

The Janspeed youâ€™re talking about was standard in the Exige/340R, and it is made for an engine with power characteristics slightly different than the stock 120BHP S1, it shifts the power higher up in the RPM range at the expense of some low end (VHPDâ€™s have less low end torque than the 120BHP Elise).
So it would be great if you can use that additional breathing capability, like if you have the 165 BHP PTP kit installed or at least a modified head, a bigger throttle body, some sort of better induction filter, etc.
When I sold mine (to a fellow SEâ€™er, but canâ€™t remember the name) he mentioned he was very happy with the power characteristics. Basically worth it if you like trackdays, as it will shift power up anyway.

Now, I changed it for an EBD ultrabore stepped 4-2-1, and it gave some improvements, again at the expense of midrange.

The EBD was supposed to be the best of the best, but then I changed to a 2bular, which has been much better and the one Iâ€™m keeping for good.

Check the power curves with those three compared:

Sanjøy · Post by **Sanjøy** » Fri Jul 14, 2006 9:54 am

Hmm so you reckon it would be best if Scott gave it to me for use on my ported head ?

Uldis · Post by **Uldis** » Fri Jul 14, 2006 10:06 am

Hmmm, depends on what sort of mods Scott has (or plans to have).

When you look at that graph remember that it's the dotted one you're aiming at.

Sanjøy · Post by **Sanjøy** » Fri Jul 14, 2006 10:10 am

Go on scott

SP Big valve VVC casting ported & flowed Mike Satur head, alu TB & NAFÂ®