how much horse 1.8

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vwbugg2275
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how much horse 1.8

Post by vwbugg2275 »

how much horse power can i get out of 1.8 with turbo and hi compression with dual carbs on it :twisted: :mrgreen:
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Briano1234
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Re: how much horse 1.8

Post by Briano1234 »

259bazillion. HP depends on the tranny, the engine how much boost and other assorted bits but it would easily be 150 or more.
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Re: how much horse 1.8

Post by Calimus »

For the sake of making your life easier, I would ditch the carbs when doing a turbo setup.

Also, you want to lower the compression on the motor for boost so you don't blow headgaskets everytime you rev it unless you place on replacing all the internals with super nice bits and special made head gaskets.

Now, I've seen JH motors (standard 1.8l cabby motors) put down 200hp at the crank with nothing more then a decent turbo and running megasquirt/digi-1/SNS for fuel management. These builds were also with nothing special done to the motor aside from maybe a mild cam.

While I know boost can be done with carbs, I've not actually seen a setup with my own eyes, so I really can't direct you on that at all.
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MAKAKO
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Re: how much horse 1.8

Post by MAKAKO »

actually.. you can run high compression turbo, you'll just need to tune it correctly.( high octane, such as E85 or C16, you will need to run very conservative timing but it can be done.) Benifits include lower boost pressures for higher output, hence the compression, also the turbo will spool quite rapidly so you will reach full boost at a lower rpm, if you selected the proper housing / turbine wheel.. it will work on pump gas if your doing low boost. as in 5-7 psi. you should have minimum rods and pistons.. but as cheap as these motors are to throw together. you should just slap in a set of audi pistons (low compression), get the rods worked on to add strength( shot peened / heat treated / cryogen) or simply purchase a set of rods( i'm a dealer for Scat and Crower) and furthermore look into an injection system for daily driver use. The High compression turbo is a possibility but it seems as if this will be your first build of any engine. so i'd suggest going the regular way first to learn the ropes. then go onto some interesting setups.

to touch on the carb turbo setup there are 3 ways to go about this. Blow Through, suck through, and boxing the carbs.

Blow through - you build a box that bolts the the intake side of your carbs( i'm assuming you speaking of a set of Webers or the like) your chargepipe from the turbo will affix to that box, were you will add the bov. You will need a low pressure high volume fpr that raises fp as you generate boost, and you'll need someone to tune the carbs for boost, aka proper jetting emulsion tube, etc. etc..

Suck through - this is were the backside of the carb attaches to the inlet of the turbo. The turbo will suck the mixture through the carb and blow into the motor. In my honest opinion, the atomization turns to poo as it passes through the system as it will pass through the compressor wheel, and intercooler, plus all the piping. before reaching your valves ... stay away from this setup.

Boxing.. you build a sealed enclosure around the entire carburetor, and connect your charge pipe to this box. it's a pain to get into the carb if you have to change settings on the fly but once tuned it's all good to go.


so those are 3 main ways of doing the carb setup.. additional to the fuel side of things put in a good holley high vol low pressure fuel pump


. next is timing...

You'll need to retard timing as you go into boost. so there are a few ways to do this.
you can run what's called Locked timing... you set it , and forget it. keep in mind most power is locked away in the timing portion of any engine configuration. but this is a safe way. set it to factory timing (aka 4-8) on these jh motors, disconnect the vac line, and run it rich.

you can run an msd Boost retard. or PN 8762.. Called the MSD Boost Timing Master.. This will be the best way to pull some extra hp from your engine. while on one of these setups. it will pull timing as your boost increases. highly suggested..

anyway if the carbs are tuned properly, and you have your timing set.. and your engine is strong.. and you have someone who knows what they are doing as far as the tuning goes... you should have a good 250 or so depending on the size of your turbo..

on that note... get a transmission that can handle it. the stock axles I wouldn't push past 230 whp or so... if you drive easy and gradually boost aka highway runs or such, then you can push more. if your dumping the clutch at each light, get axles.

You'll need a clutch, you'll definitely need better brakes. and make sure the suspension is all up to par. including bushings.


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Re: how much horse 1.8

Post by Briano1234 »

dam nice first post........holy crap
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Re: how much horse 1.8

Post by gull »

MAKAKO wrote:on that note... get a transmission that can handle it. the stock axles I wouldn't push past 230 whp or so... if you drive easy and gradually boost aka highway runs or such, then you can push more. if your dumping the clutch at each light, get axles.

You'll need a clutch, you'll definitely need better brakes. and make sure the suspension is all up to par. including bushings.
Just as a side note, some of the rally guys that run Mk.1 cars are starting to swap to Mk.3 front suspension, to get the stronger axles and better brakes...I don't know what all is involved in the swap, but I thought I'd throw that tidbit out there. These guys have serious axle issues because of the rough roads they run. It's not uncommon to replace axles after every couple events.
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