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TommyC

Crawford Performance Intake Spacers

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I've just stumbled across these...

https://www.part-box.com/crawford-big-power-blocks-intake-manifold-spacer-toyota-gt86-subaru-brz-12-17-b0400

...and I'm rather sceptical about the claims. For a simple 'bolt on' lump 19bhp and 15lb/ft seem a bit too good to be true! However, I know that manufacturers can often restrict intake tracts to control power output to fit into 'requrements' (like BMW and Vauxhall/Opel have in the past). I mean, Crawford are rather good at what they do in the US, but really??!

I suspect the cash for these is better spent on other things? 🤔

Has anyone actually bought some? Are they proven?

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8 minutes ago, TommyC said:

I've just stumbled across these...

https://www.part-box.com/crawford-big-power-blocks-intake-manifold-spacer-toyota-gt86-subaru-brz-12-17-b0400

...and I'm rather sceptical about the claims. For a simple 'bolt on' lump 19bhp and 15lb/ft seem a bit too good to be true! However, I know that manufacturers can often restrict intake tracts to control power output to fit into 'requrements' (like BMW and Vauxhall/Opel have in the past). I mean, Crawford are rather good at what they do in the US, but really??!

I suspect the cash for these is better spent on other things? 🤔

Has anyone actually bought some? Are they proven?

https://motoiq.com/tested-crawford-performance-fr-s-brz-power-blocks-intake-manifold-spacers/3/

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5 minutes ago, nikndel said:

I think you will find general opinion is keep your money for other things

@TommyC To be honest, any sort of power upgrade on NA car is valuable. If you think you're going to stay away from Forced Induction for reliability or other reasons I recommend getting this, a decent intake, exhaust manifold and a good cat-back. All that with a remap will make a big difference. Of course, if you are planning on getting a supercharger or a turbo, you don't need to spend this amount of money on the above mentioned mods at all. So at the end of the day, it's up to you.

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Those powerblocks do well on otherwise completely stock car. For some loss near redline, they add noticeably at lower/mid rpms (which also happen to be used more at daily driving). They move "optimisation", power & torque peak to lower rpms.

They make a less sense to be used with custom ecu tune/other boltons though.

Imho best bet for NA power gains is aftermarket airfilter+catless header+ecu tune. And, if at local fuel stations available, E85 as fuel (+E85 tune or flexfuel kit & flexfuel tune).

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Put simply you can get far better gains from a decent manifold, decat and remap. This is what the majority of us have done. If fitting the Crawford inlet manifold spacers is all you are going to do in terms of tuning then it could be beneficial it seems. 

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Thanks for all the replies and explanations.

I intend to follow the well trodden NA path... (for now). These just seemed to be an oddity in my understanding of how changes in the inlet can manipulate performance.

That said the other NA 'bolt on' inlet tract mods I know of get their gains because the manufacturer deliberately de-tuned the engines before putting them on sale.

 

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It's just like with runner lengths on exhaust header (eg. Ace header, with 150/250/350 overpipes) one can manipulate best scavenging on certain rpm range, with making intake longer one can shift optimization of input. IIRC something to do with resonance. Most commonly it's just moving peak elsewhere, not "gaining". Gain somewhere, loose somewhere. IIRC there were cars (or motorcycles?) that had dual path designed intake with valve closing one to switch between shorter or longer according to rpms engine was running at.

Here is thread about those spacers if you want to read more. Problem being that since it came about, many images, eg. dyno charts at OP, probably gone due photobucket fiasko. (EDIT: found MotoIQ's blog on this outside forum, with pics)

There is one extra bit i don't like in BPB, - their material. Imho being from metal makes them more expensive and also susceptible to heatsoak.

As i wrote in previous post, imho these might be nice addition on car w/o aftermarket headers, less so on one with them, but probably wouldn't get in two cases - if car would be running on E85 (as imho most gains from E85 come at top rpms, from were BPB blocks shift power to lower range), and if car will have forced induction (probably one can even loose power. IIRC with turbo/supercharger car benefited from opposite - shorter intakes).

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I've got a set fitted and I have noticed a difference in the engine being a bit quicker on acceleration, seems to pick up quicker.

I know I've sacrified the very top end of my rev range (at this time) but to be honest how often do you redline when on normal roads.

I've got a baseline dyno done at TD, so one of my things to do this month is get booked in for the manifold and overpipe fitting and remap - then I'll have the dyno's to compare the non BPB, with just BPB and then BPB + TD NA kit.

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It's more question of not 'how often', but rather for 'how long'. And that is almost always second or less, unless it's some drifting, where one whole slide w/o upshifting keeps readlined with rpms bouncing of redline cutoff..

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16 hours ago, TommyC said:

'Walnut blast'?!!

What's that then?

From what I understand Direct Injection systems cause a lot more carbon buildup than a regular engine because of higher compression and a better burn. There are a few discussions about this on various GT86 forums but I don't actually know any UK GT86 owner that's had this issue yet.

The way they clear it out is to fire walnut shell chippings at the build up under high pressure. Apparently its the best way to clear it off without doing any damage to the engine.

Quick google - https://www.terracleanswaffham.co.uk/walnut-blasting

My understanding is that carbon buildup in DI Engines is down to poor maintenance and I've also heard that you can get carbon buildup if you only ever drive for economy (not sure how much truth there is in the latter).

But seeing as my 86 is my dedicated track car I'm happy that it should never get carbon buildup. It only ever sees low rpm on the way to and from the track lol

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Oh ok! Yeah I've heard of this being used for cleaning deposits off of Gas Turbine engine compressor sections whilst they're running!!

Although they tend to use de-ionised water these days...

 

First I've heard of it for piston engines, but every day's a school day 🙂

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Imho that how drastic that problem of carbon deposits might be, is slightly exaggerated, at least with modern fuels, that these days usually contain also misc additives including ones that reduce carbon buildup. I don't expect it to cause noticeable problems any sooner then by mileage wear of other parts engine will need overhaul. Or also possible, that car will be sold prior that.

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Well I've booked in for the work at TD at the end of the month.. will see what the pre-remap dyno run says in comparison to the baseline taken pre-BPB's being put in a couple of months ago...

Then it's a case of seeing what the re-mapping makes of the standard TD manifold, overpipe with the BPB''s hence them keeping it a bit longer than a normal remap session.

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On 01/11/2018 at 8:10 PM, TommyC said:

'Walnut blast'?!!

What's that then?

Used to have to do this on Mitsubishi GDi engines when the valves carboned up. Cannot see this being an issue as we have port injectors as well. 

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Unfortunately TD didn't dyno with just the blocks prior to the manifold and remap.
However, the dyno shows the power shift as expected. The benefit is a touch more torque lower down the band. I uploaded a photo of the dyno to the FB page. Will upload it here when I get chance.

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