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Author Topic: Precast delete + fuel pump or downpipe  (Read 2307 times)

Offline wrlcs

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Precast delete + fuel pump or downpipe
« on: September 04, 2016, 10:02:37 am »
Hi, I'm about to book in at Rtech and will seek advice from them. However, I was wondering what thoughts are on a choice between a precast delete with Loba fuel pump or a downpipe e.g BCS with cat.   These appear about the same price and as I don't expect to do any further mods then advice on the merits of these would be useful. The cam follower etc is covered so no help needed there.  Brendan

Offline AJP

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Re: Precast delete + fuel pump or downpipe
« Reply #1 on: September 04, 2016, 12:34:36 pm »
Hi, I'm about to book in at Rtech and will seek advice from them. However, I was wondering what thoughts are on a choice between a precast delete with Loba fuel pump or a downpipe e.g BCS with cat.   These appear about the same price and as I don't expect to do any further mods then advice on the merits of these would be useful. The cam follower etc is covered so no help needed there.  Brendan
I think in terms of gains a proper 3" downpipe will give you a little more than a precat delete + uprated pump. But you'll get the best out of an uprated pump if you pair it with a 3" downpipe, whereas you're still throttling flow with the standard downpipe even if you delete the pre cat.

It's worth mentioning that when I got my Stage 2 R-Tech map to compliment my full 3" Powervalve I started getting fuel cuts. Basically the exhaust improved flow massively but the standard fuel pump just couldn't supply enough pressure to meet the demands of the map. So I then had no choice but to buy an uprated fuel pump. I'm still on the Stage 2 map, but in theory I can now update it to 2+ as I've got the uprated pump.

If I had the chance to do things differently I would have done the exhaust and pump, and then the map. I'm not saying you'd definitely get fuel cuts if you got a 3" downpipe then Stage 2 map on the stock pump, but if anything my experience indicates that the stock pump can drag its heels behind the rest of the hardware once you start turning the boost up.

If you can't budget for both a pump and a proper downpipe/exhaust then I'd advise doing the pump + precat delete, which R-Tech would map to Stage 1+. The sooner you uprate the pump the better. Then make sure the downpipe is next on the list; you'll get lower EGTs, better flow, more power, and it'll sound nicer.

Stage 1+ should drive really nicely though. The biggest fuel demand is around 3000-3500rpm. Anything you can do to improve fuelling here will make the car feel much stronger in the mid range.

Offline wrlcs

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Re: Precast delete + fuel pump or downpipe
« Reply #2 on: September 05, 2016, 05:16:25 pm »
Thanks, that makes good sense.