Supercharged 7a?

[Jolfa]

Just having a bit of a ponder on the matter, is all my standard 7a management likely to be up to the job of a bit of boost (in the shape of an Eaton M45)?

Engine and everything associated was from a 1992 90 Sport if it matters.

Just seems a more financially viable way to get a few more horses than to go 20vt!

[Error404]

never going to be cheaper, you can chuck in a 3B for about £800. But definately more interesting. Yuo would need to use custom bracketry etc obviously, maybe a custom crank pulley. then you need to find a home for it - where the A/C comp normally sits would be the most straight forward, then theres custom pipework, intake etc to think about.
I'm sure you could cook something up with the 5hitachi, but its....err 5hit. Be better to look at a standalone of some kind IMHO... but this all goes against your budgetary requirements I guess........ lumpy cams, solid lifters & throttle bodies is the other option. 20vt really is the easiest and cheapest way to go

[quattro_king01]

hi my m8 got supercharged cq toni imp i will get him to post pics etc gr8 idear

[Jolfa]

Bodies and cams was the other thing I was looking at, but it'd be the same money, same amount (if not more) work, have less increase at the end of it and there's f*ck all in the way of cams for 5 pots out there

If the standard injection would keep up with the extra air going in, then the rest would be relatively easy and cost sub £200 :mischeif:

£800 is wayyyy out of budget, my last project has 300bhp and cost less than £100 to put together this is practically a blank cheque car compared

[prj]

I would not risk it on standard injection.
I might be really wrong here, but wasn't the 7A controlled by a Hitachi ECU?
And those are Speed-Density AFAIK.

If it's MAP sensor is just enough to measure atmospheric pressure, then the ECU won't even know there is additional air going into the engine...

I have looked through the binary file read off a 2.6 V6 with a Hitachi ECU, and while some maps can be identified, it is a completely different system to Motronic and it is not likely a lot of people know how to remap it.

A better bet would be to use megasquirt to control the engine.

[Error404]

Bodies and cams was the other thing I was looking at, but it'd be the same money, same amount (if not more) work, have less increase at the end of it and there's f*ck all in the way of cams for 5 pots out there

If the standard injection would keep up with the extra air going in, then the rest would be relatively easy and cost sub £200 :mischeif:

£800 is wayyyy out of budget, my last project has 300bhp and cost less than £100 to put together this is practically a blank cheque car compared

cheap power aren't two words that can be used together when talking about these cars unfortunately. The entire Hitachi system is crap, 7A injectors are 5hite to say the least, maf and throttle body are restrictive even as stock. Don't forget you'll need brakes too, theres £500....
Good luck is all i'll say..

[Acidburn]

I would not risk it on standard injection.
I might be really wrong here, but wasn't the 7A controlled by a Hitachi ECU?
And those are Speed-Density AFAIK.

A better bet would be to use megasquirt to control the engine.

You could get two ecu's with the 7a's an early and late one.

There are a few people going supercharged 7a, ben on classic audi and 86style/gompa on here.

and yeah megasquirt or the likes probably easiest management to sort, plus you'd keep a lot of the sound i'd have thought

[Jolfa]

cheap power aren't two words that can be used together when talking about these cars unfortunately. The entire Hitachi system is crap, 7A injectors are 5hite to say the least, maf and throttle body are restrictive even as stock. Don't forget you'll need brakes too, theres £500....
Good luck is all i'll say..

Don't be so defeatist Common upgrades for the injectors, MAF and throttle body? Brakes are catered for Everything's cheap if you do it the skinflint way, so far I'm £100 up from getting the engine in the first place

There are a few people going supercharged 7a, ben on classic audi and 86style/gompa on here.

Any links to builds or such? Can't find any info on the matter?

[mcandmar]

I got to agree with error404, its crap. And add to that the fact that nobody can remap it. If it were me i would get a loom/ECU from a 3B as your getting a better system, a system people understand and can remap, and more importantly one that can handle positive intake pressure. As Prj said the 7A is a speed density system so there is no map sensor, only a MAF, engine speed sensor, and throttle positon sensor. Infact why not go all out and use an ABY setup and convert to coilpacks.

or you could just go stand alone.

[Jolfa]

Ah but then if I was to get the 20vt bits, I may aswell go the path of least resistance and just turbo it... I'm really after a few cheap horses, anything but bike carbs!

Is the spark and fuel system all part of the same ECU package? Could I use the spark bits off a 10v K-Jet setup (as I know this is seperate) alongside some other kind of fuel management?

[Error404]

Ah but then if I was to get the 20vt bits, I may aswell go the path of least resistance and just turbo it... I'm really after a few cheap horses, anything but bike carbs!

You're not listening. We keep trying to tell you its not that easy

[20Vcqdriver]

Hitachi injectors are crud, I only ever managed to get 190bhp out of my 7A after a lot of expense with larger V6 MAF, uprated injectors, rechipped switchable ECU and then got kicked up the rear by a friend who decided to fit a modified K-jet system to his and got just over 200bhp for half the money In fact it was this that broke me and why I now have a 3b
Supercahrging 7A would be an interesting engineering project, but cheap, er... no !

[Rusty]

Better way of looking at it is, do you want something that is proven to work, reasonably simple to do and that lots of others have got (20VT) or, do you want something a little more troublesome to get right that will be rare and different (SC'd 7A). Both routes will cost a bit of money and both methods will improve power.

I'd suggest that sticking with the 7A injection would be an error. Either look at getting a 20VT injection setup running on VEMS or head towards stand alone.

As above, fitting a 3B is quite cheap these days so I'd have to say that the SC option would cost more, perhaps about the same as getting the more modern ABY in there...

Whichever way you go, you'll need a full chassis restoration and upgrade, larger brakes and wheels to suit. To leave these bits out would be plain daft and it'll easily add £1k to your budget to do it anywhere near properly, if you get carried away then £2k+ is easily spent on upgrading things to poly, delrin, alloy, coilovers etc.

[Jolfa]

a friend who decided to fit a modified K-jet system to his

Tell me more, I can work K-Jet and have a full 10v setup I'm removing to fit this 20v :mischeif:

The problem is I just have no clue how much Megasquirt (or similar) would cost, as that's the only thing that would potentially cost any real money...

[Gompa]

anything is possible its what you wanted out of it at the end that differs. I got a 7A out of a 90 i picked up for pennies by the time i sold parts/scrap i had a free engine so it didnt matter if i blew it up. I got an M62 charger from a merc (i think the M45 will be a bit small for a 2.3 its built for 2ltr maximum really) investigate and you will find loads. I got an S6 pulley so i can run a newer belt the same thickness as the chargers pulley and came up with a tensioner system as part of the charger bracket that runs a genuine audi tensioner. intercoolers can come from anywhere for cheap and then spend the money on areas such as megasquirt and mapping.
Personally i believe if its pure power your after forget the charger idea not only did audi turbo the I5 but there is 20years of tuning out there. I fancied it for A. a change B. the sound C. cos i got drunk and bought the charger off ebay