New 2Bular 4-1 Manifold for Toyota SC Engine
Discussion
Had Jim's new revised 4-1 manifold fitted today and decided to follow the de-facto standard protocol for fitting any modification (baseline dyno, fitting, mapping, post dyno) to keep everyone happy who is surely to dispute such information presented below. Bottom line is that its given a 25bhp & 12lb/ft gain which is pretty incredible.
Peak figures:
Before: 216whp, 145lb/ft (Katana+Induction+2Bular De-cat+8x24GT3GT3+custom map)
After: 241whp, 157lb/ft (Katana+Induction+2Bular 4-1+Flexi De-cat+8x24GT3+custom map)
Runs were same day, same operator.
so with a 12.5% correction that's 271bhp & 177lb/ft. I also had the K&N air filter cleaned prior to both dyno's just so there was no excuses on power output or any ponnies left sitting on the bench.
Total gains were 25whp gain and 12/ft for the 2Bular 4-1 and Flexi-decat which is fantastic.
Essex Autosport did the mapping and were also surprised at the gains.
Seems Jim's new 4-1 design is worth every penny![url]
|http://thumbsnap.com/e5wXAtel[/url]
Peak figures:
Before: 216whp, 145lb/ft (Katana+Induction+2Bular De-cat+8x24GT3GT3+custom map)
After: 241whp, 157lb/ft (Katana+Induction+2Bular 4-1+Flexi De-cat+8x24GT3+custom map)
Runs were same day, same operator.
so with a 12.5% correction that's 271bhp & 177lb/ft. I also had the K&N air filter cleaned prior to both dyno's just so there was no excuses on power output or any ponnies left sitting on the bench.
Total gains were 25whp gain and 12/ft for the 2Bular 4-1 and Flexi-decat which is fantastic.
Essex Autosport did the mapping and were also surprised at the gains.
Seems Jim's new 4-1 design is worth every penny![url]
|http://thumbsnap.com/e5wXAtel[/url]Edited by STEVEY_SC on Wednesday 22 December 09:23
Herman Toothrot said:
Is that any suprise? Its probably all down to the decat which unless you have a "friendly" MOT man will have to go back in once a year.
Who cares,if correct, a genuine 25bhp gain with essentially just a manifold and cat is quite frankly outstanding./You're not helping my wallet
The Bandit said:
Herman Toothrot said:
Is that any suprise? Its probably all down to the decat which unless you have a "friendly" MOT man will have to go back in once a year.
Who cares,if correct, a genuine 25bhp gain with essentially just a manifold and cat is quite frankly outstanding./You're not helping my wallet
Outstanding how, in value for money terms? Cutting the cat out and just replacing with a straight secton on any forced induction car will allow great gains, the CAT's the most restrictive bit. You won't see many posts about it on new cars like toyota engined Elises because a CAT is compulsory for road use, it'll never pass a "by the book" MOT without one so most people can't be bothered with the hassle. I'd bet on 5bhp for the manifold 20bhp for the decat, this is old hat for anyone who's tuned a forced induction car surely?20bhp on a de-cat? if that was the case I think 90% of the tuned Yota Elise/Exiges would be running around with de-cats.
I remember the DC5 manifold on the Honda conversions gave similar gains...
I have a sports cat anyway which will probably be switched at some point.
/You're not helping my wallet Outstanding how, in value for money terms? Cutting the cat out and just replacing with a straight secton on any forced induction car will allow great gains, the CAT's the most restrictive bit. You won't see many posts about it on new cars like toyota engined Elises because a CAT is compulsory for road use, it'll never pass a "by the book" MOT without one so most people can't be bothered with the hassle. I'd bet on 5bhp for the manifold 20bhp for the decat, this is old hat for anyone who's tuned a forced induction car surely?
I remember the DC5 manifold on the Honda conversions gave similar gains...
I have a sports cat anyway which will probably be switched at some point.
Herman Toothrot said:
The Bandit said:
Herman Toothrot said:
Is that any suprise? Its probably all down to the decat which unless you have a "friendly" MOT man will have to go back in once a year.
Who cares,if correct, a genuine 25bhp gain with essentially just a manifold and cat is quite frankly outstanding./You're not helping my wallet
Outstanding how, in value for money terms? Cutting the cat out and just replacing with a straight secton on any forced induction car will allow great gains, the CAT's the most restrictive bit. You won't see many posts about it on new cars like toyota engined Elises because a CAT is compulsory for road use, it'll never pass a "by the book" MOT without one so most people can't be bothered with the hassle. I'd bet on 5bhp for the manifold 20bhp for the decat, this is old hat for anyone who's tuned a forced induction car surely?STEVEY_SC said:
20bhp on a de-cat? if that was the case I think 90% of the tuned Yota Elise/Exiges would be running around with de-cats.
I agree they would if it was road legal, which it isn't.. not a hope in hell of a decatted toyota engine elise passing an above board MOT.I used to swap the cat out of my Eunos for MOT's as I had a bigger gain, about 40bhp as without the cat boost could go up and EGTs could be decrease without the resistance offered by the cat. It was a load of hassle as mapped correctly without the cat inserting the cat, restricted the flow messing up the map so I had to load up a with cat map as well at MOT time. Pain in the behind. I've reshelled the car into a 1989 shell so I don't have to mess about in the future.
Edited by Herman Toothrot on Tuesday 21st December 22:40
Herman Toothrot said:
Is that any suprise? Its probably all down to the decat which unless you have a "friendly" MOT man will have to go back in once a year.
You need to read Steve's post again - this time engage what you call a brain and maybe you'll understand.Steve had the de-cat and the GT3 system already fitted and MAPPED IN. I wanted this car on a dyno, on the same day, with the same operator for a base run THEN change out the std POS manifold for my 4-1. Any change (good or bad) would then be down to that 4-1. Wayne told me the change in AFR was dramatic, so we knew air flow was improved and once mapping/fuelling was dialled in, the gains were noted.
STEVEY_SC said:
Peak figures:
Before: 216whp, 145lb/ft (Katana+Induction+2Bular 8x24" GT3+custom map)
After: 241whp, 157lb/ft (Katana+Induction+2Bular 4-1+Flexi De-cat+8x24" GT3+custom map)
Runs were same day, same operator.
Before No Decat, After Decat.Before: 216whp, 145lb/ft (Katana+Induction+2Bular 8x24" GT3+custom map)
After: 241whp, 157lb/ft (Katana+Induction+2Bular 4-1+Flexi De-cat+8x24" GT3+custom map)
Runs were same day, same operator.
He wrote it himself, clear as day it had a decat for the 2nd run, not for the 1st.
Edited by Herman Toothrot on Wednesday 22 December 09:20
purpleperil said:
321freeflow said:
Sorry, under stress today - boiler broken down, stuck in house till the heating engineer gets here!! Hurry up!
Not a frozen condensate pipe is it? - got me last week worth a look and save you a few quid if it is 
Ah, that was the old-design Euro Exit Rene - didn't really work; you see the pipe from the Cat to the T between the silencers? It's just a bit too close to the diffuser for my liking - given the engine movement on the 2zz-ge. That prototype is still on the car, still working but I took the Cat pipe up and behind the silencers on the Mk2 version.
Not a lot of room on these tbh. The whole exhaust bolted to the std manifold btw
Not a lot of room on these tbh. The whole exhaust bolted to the std manifold btw
Edited by 321freeflow on Thursday 23 December 19:33
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