compression through the rev's

[DiYMCRT]

quick one here, my mate went a trackday in the 2 (rev1) and now is thinking he wants a little more torque in the 2, simple answer boost!

i was told the rev1 only runs 9.2:1 compression don't have a tester to check (i can lend one if necessary) can anyone confirm this?

so he has a turbo from his old fiat coupe in the garage so the idea was to use that or maybe swap that for a smaller one and run between .5 to .7 bar if the compression is 9.2:1 it should cope with this no problem to my knowledge the only internal diffreneces between ge and gte are the oil squirtes and piston's and a gte hg would be the obviouse replacement for the standard and inevitable to fail hg.

now fueling this is where i'm asking really, the inlet maifold's plenum after the tb and before the acis butterfly's has a banjo bolt carrying fuel which i presumed to be the cold start? or is to part of the acis?

well the plan was remove that bajo bolt and fuel line etc and put a injector in there running off the standard ecu, thought's people?

thanks all

[T.F.S.]

compression tester wont tell you anything mate (other than how much compression the engine has which is totally different to compression ratio)

as for fifth injector on stock ECU, i think you should stay well away from the car

[DiYMCRT]

as for fifth injector on stock ECU, i think you should stay well away from the car

well at least someone replied, you don't ask you won't learn.

fifth injector has been done many times matey not sure if it's ever been done on mr2, but the cold start acts essentially as a fifth injector when operational. can you actually back up with knowledge and reply to why this would be such a problem?

[T.F.S.]

never seen it controlled by the stock ECU

i fit/sell nitrous kits which you could regard as a fifth injector...you get reasonable distrubition to most cylinders when set in the right position and pointing at the right angle...sometimes we get better power on smaller shots with a single injector kit rather than going direct port

the mixture when sprayed with nitrous becomes far finer though, a far better properly designed injector with 980psi of liquid nitrous crossing the path of the fuel simply atomises a hell of a lot better than a cold start injector

these injectors are triggered via external control even if that is just a throttle microswitch but not the ECU because there is no output for this

what may be an option for you (a far better one IMO) would be a WI kit with a rather nasty homebrew mix...if you decide to go down the fifth injector route

[DiYMCRT]

i'll be honest i'm not sure how it's done on the stock ecu but the ford people seem to buy a controller to run it as you say, i have heard of people splicing into loom's, i'm not sure about this i've never seen it working when spliced in, the cold start seem's to be a common place for the 5th injector as it as you say distributes fuel reasonably evenly across the cylinders, they also lower the fuel pressure to help the car give better off boost economy

[craig_mr2_mk1]

My mate used to run a 5th Injector on his RS Turbo but that was using a Type of piggy back which runs just that 1 injector. I believe it's spliced into the original loom and is activated when it see's boost. I don't think it's a very accurate way of adding fuel though TBH.
Why not buy a rev 1 loom, ecu, Injectors, AFM ect, then get the Manifold Tubro, down pipe and exhaust and your pretty much there for a turbo conversion.

[DiYMCRT]

yeah that would be another option would need to confirm the compression is as low as thought but cost would have to be compared, it was more of a spur of the moment could we do it with scrappy bits and bobs kinda thought not sure if he's keeping the car now there's a really nice e30 325 with is gearbox (lsd) down the road and he will take me mates rev1 in px and knock 1k off price, he can't get 1k for the mr2 so seem's a good deal atm

[BenF]

quick one here, my mate went a trackday in the 2 (rev1) and now is thinking he wants a little more torque in the 2, simple answer boost!

i was told the rev1 only runs 9.2:1 compression don't have a tester to check (i can lend one if necessary) can anyone confirm this?

I can't find the figures, but I'm fairly sure the Rev1 and 2 are 8.8:1 and Rev3+ were a little lower. This is one reason why the earlier cars are a little more sensitive to knock and fuel quality.

For track use, think carefully before going for more boost.

Higher intake temps as you're running on throttle mean you should look at your intercooler and intake.

I tracked my old Rev2 @ 14psi with standard internals and ECU fueling - going to 17psi actually made very little difference on track or in a straight line drag race.

[Marf]

Why not just do a turbo engine swap?

Pretty sure the insurance increase will be broadly similar to bodging on a random turbo and cludging the fuelling.