2ZZ PPE manifold with Janspeed backbox

[Dudi]

Hi guys,

 I'm desperately hoping to get the car sorted before it's first trackday sometime in April, I feel like I've been binge posting for advice but do appreciate the responses.

My 2zz swapped car has a cheap eBay manifold which is looking a little worse for wear. I'm looking to upgrade to the PPE 4-1 manifold however would like to stay 2.5" for best flow. I've sent Janspeed a message but no reply regarding whether the connector is 2.5" or 2.25".

Could someone here help with this info?

Many thanks.

[mikek]

Pretty sure it's 2.25

[jonty]

You'll be better off with a step after the PPE than the eBay manifold, the only time you hear people complain that the 1zz to 2zz power difference wasn't as much as they imagined was with a Che/eBay manifold. You can always get someone to modify or make up a new back box in future and sell the bits you don't need.

[Dudi]

You'll be better off with a step after the PPE than the eBay manifold, the only time you hear people complain that the 1zz to 2zz power difference wasn't as much as they imagined was with a Che/eBay manifold. You can always get someone to modify or make up a new back box in future and sell the bits you don't need.

Hi Jonty, appreciate the response but the first bit doesn't make much sense to me. Could you clarify?

[jonty]

I read the question as you're unsure if the inlet of the japspeed box is 2.25" or 2.5", to match with PPE 2.5" outlet. My advise is to go for the PPE regardless, since the step (if it exists) can be remedied in future, and even with the step will do less harm to performance than the eBay manifold is currently doing - from memory, I've seen dyno graphs showing about 20bhp lost due to ebay/Che manifolds

[Dudi]

Ah I understand, this is exactly what I was wondering. Whether narrowing of the diameter would cause flow issues as what I was actually hoping to do was to maybe get my current midpipe and backbox pipes reworked by an exhaust fabricator to be 2.5".

Thanks again.

[JoeCool]

There are 2 things that make people say the 2ZZ conversions suck:

1) The 1zz gearbox ratios and

2) The cheap ebay swap manifolds!!

[PhilMC]

Why not get a standard Celica manifold modified to come above the subframe and a custom 200 cell sports cat section to mate with any exhaust in the standard 1zz position.

I know Patrick at Rogue sell these off the shelf, but I had mine done by the Liverpool gurus during the conversion last year. Supposed to be the best flowing solution for this conversion.

[jonty]

what I was actually hoping to do was to maybe get my current midpipe and backbox pipes reworked by an exhaust fabricator to be 2.5"

Exactly, it's not a particularly big job. I'd do either that or as Phil says with stock celica manifold; whatever fits your time/budget restrictions... But either way get rid of the eBay manifold. With my 2zz (and non-eBay exhaust) a mate asked if I had only gone to full throttle at 6k, because the cam change is that hard.

[Dudi]

Why not get a standard Celica manifold modified to come above the subframe and a custom 200 cell sports cat section to mate with any exhaust in the standard 1zz position.

I know Patrick at Rogue sell these off the shelf, but I had mine done by the Liverpool gurus during the conversion last year. Supposed to be the best flowing solution for this conversion.

This is news to me and certainly more appealing than the current exchange rate + VAT + customs on the PPE item. Is the Celica manifold really as good as the PPE? I've seen a pic of it and it kind of looks like 4-2-1 but possibly 4-1.

Would a PPE give better performance if I was to use a standalone ECU/Apexi PFC in the future?

[JoeCool]

The celica is a 4-1 but it's divided at the collector with a proper 'spike' to promote proper pulse scavenging. Put it this way- I've got more faith in Yamaha and Toyota to engineer a high performance manifold correctly than random aftermarket tuners.

[Dudi]

I'd go along with that to a point but OEM manufacturers have plenty of constraints such as budget, various MOT type legislations in multiple countries, acoustics to cater to a more mainstream market etc. I've certainly come across plenty of aftermarket products where they're engineered to a more narrow spectrum of use i.e performance at the cost of everyday usage where they perform better than the stock item.

I'm definitely tempted to try the Rogue parts, it's a hell of a lot cheaper than PPE.

[shnazzle]

There's plenty >200hp 2zz projects out there running the cut 2zz stock manifold. There's no arguing with hard figures

[lamcote]

Has anyone tried fitting the 2zz manifold to the 1zz?

[jonty]

The celica is a 4-1 but it's divided at the collector with a proper 'spike' to promote proper pulse scavenging. Put it this way- I've got more faith in Yamaha and Toyota to engineer a high performance manifold correctly than random aftermarket tuners.

Whilst I understand with what you're saying, if you look at the threads on spyderchat about the PPE system you can see a lot of work has gone into simulation and dyno developing, and as someone who works for a large automotive manufacturer I can tell you cost will win vs performance, so their decision to go 4-1 could be as much driven by cost (fewer parts, fewer welds) than absolute performance.

I'm not saying modified OEM is a bad choice (and in fact if I was doing it again is the route I'd choose), but have your eyes open that an OEM design will be compromised to save pennies, let alone pounds!

[JoeCool]

Oh I agree, but the ppe is really developed as a high rpm exhaust, and the cost is.... Well.... Commensurate with the development that's gone in.

If you want the absolute best, I think ppe or TRD manifold is the way forwards. If you're not made of money I'll take the r&d that Toyota put into an engine they were very keen to keep competitive with Hondas contemporary offerings.

As for 'no name's options and I somewhat include the mwr swap header with this, you pays yer money and takes yer chance.

[Dudi]

So I took the forum advice and ordered a modified Celica GTS manifold, decat pipe and backbox from Rogue Motorsport.

I'm kind of second guessing the decat order though, I'm a little worried it might fail noise tests on some circuits. Will have to wait and see.