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Hi there thank you for looking. I’m trying to find out what mods i can to my 20valve 7A without spending too much money. I would like to put a 3b inlet manifold on. But would I gain much power with it. Is it worth putting a set of s2 injectors in? Can 7A’s be remapped or chipped? I know I can put a set of cams in but don’t know the specs of the 7A so I don’t know what would be better. Thank you for your time and all posts will be welcome thank you
theres a few threads on here about increasing the output of the 7A.
As stock the 5hitachi system is basically junk, injectors suck. MAF is restrictive. Head doesn't flow that well. Earlier tubular EM is an upgrde for the later cars, also loose the cat.
A decent porting and valve job, set of carefully chosen cams and some individual throttle bodies would be the way to go IMHO - but it'll never be a Honda.
Easier, cheaper and better VFM to do a 20vt upgrade if more power is your goal - but it'l never sound as good as a 7A
Panthero Coupé quattro 20vt
Indigo ABY coupé
Imola B6 S4 Avant
dont bother with 3b manifold, the runners are to short so all do lose power in the tuned band which is about 4500-5500 rpm and there no extra taper or balance flow to be had either. Go with ITB or a custom tuned plenum style. Like this
As for early 5 branch its meant give extra 10bhp, so worth having if can be had cheap. Could do better if really wanted go custom, but either very expensive or needs serious fab skills make fit 5 primary fit down past firewall, however I have been thinking about 5 branch for my kv 90 and an thinking going down behind the grill as seems more space. No need keep the cat either as all 7A powered cars date before mandatory
I found the exhaust ports had quite a steep in them where two passages meet and there was fair bit casting flash around the bowls so a mild bit of porting would be beneficial
Other option is bigger stoke using a diesel block and crank so more displacement, can cope with stock rev limit. Or other option reduce stroke with a 2L block and crank so make rev to 10k with some radical cams.
However just want some quick and easy increases, go with a earlier tubular, de-cat and high flow exhaust, 034 motorsport injector conversion, bigger maf of a V6 along some head porting and general tune up of engine parts amy see improvement and better drivability
2nd the 5-1 manifold and cat bypass, they made the biggest difference to mine. Head porting helped too but the gains arent worth the money IMO. I only did mine as i had to take the head off. If i was to spend any money on this engine a new set of injectors from 034 would be top of the list.
Also you could keep an eye on ebay.de for chips, i picked up one for €40 which worked surprisingly well. Just note there are two ecu versions depending on the age of the car. Early ECU's have two plugs with a part number ending with 266, later models with the cast manifold have a four plug ecu with part number 266D.
91CQ20v - Gone to a new home
93UR-S4 - The Magic Carpet
94S2Bus - The Emerald Express
Earlier cars had a tubular and no ECU, 91 was the change over later cars had ECU and a cast manifold. ideally have a tubular manifold and an ECU for best results. The tubular manifold on my later car made the biggest difference, it pulls an extra 1000rpm earlier and the engine note is much more audible.
034motorsport provide a chip which is mated to the bosch injectors. Both together claiming 18-20bhp assuming the engine is in A1 condition of course. The Hitachi injectors than come on the car are a weak link.
Rehash the air intake helps on the pick up, the BMC CDA style carbon can is supposed to make a good improvement as well.
As well as the 3in MAF conversion there is also teh Throttle Body to be P&P'ed, can increase the flow there and improve throttle response.
If your really flush there is a turbo conversion from 034 for the 7A
There is a 7A stroker on motorgeek which is knocking on for 300bhp but has had daft money thrown at it.
Or there is alwasy the NOS route, Nogin on audifans has gone that way after doing all of the above.
4V6 has P&P results from the head
Thank you for all the replays I’ve got a stainless exhaust to put on it with cat buy pass pipe and got a branch manifold to put on it. It’s on a j so I think its 91 92 reg so I would assume it’s got an ecu. Is the v6 maf conversion a straight swop? Is it worth putting a different inlet manifold of a s4 or a Wagner manifold.
ok looked at v6 maf think i can do that easy enuff. 034s injector kit is it any good i know the reviews look ok but it $400 worth about 10hp. is it not worth puting a 3b inlet on it if not does any one know of any better then the 7a thank you
I guess an advantage 3b manifold would be ability use bosch injector without any adaptors. Will need make an adaptor for the throttle or have the ecu re programmed to work 3b throttle.
Theres nothing all that wrong with the 7a manifold, it got small volume which good throttle response and runners are an appropriate length. What i dont like about it is the tight turn and the small throttle. I'm personally making a manifold for my 7A because of a space requirement and and its turning out similar to a AAN manifold but with lots of taper on the stacks and a 70mm throttle
the injectors do tend to go above about 120k anyway, should have had the bosch ones from the start. The dollar was 1.6 to the pound last month and is still cheaper than buying new hitachi ones. Bearing in mind at 20 years old they arent going to be in great condition.
Its not a turbo changes will make small improvements versus the cost outlay. I know 3 folk with the 034 injectors in 7As all have noted the improvement, specifically smoother delivery and revs quicker.
The jist of the MAF swap is the increase in CFMs
Get the air in quicker, sharpen up the throttle. Now its a 471A MAF you need ie post 93, the pre 93 2.8 MAFs carried the 471 code and were a 2.5in bore also. from memory its a 3 wire to 4 wire swap.
The sensor reads throttle postion, however the 7a throttle has two stages where at the start olny opens a small throttle and then half way open begins open a larger secondary throttle. On 3b the throttle is a single throttle bore. Also the different cross section will have an effect.
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