Engine Internals Question?

[TotalEclipse112]

I was thinking on putting a turbo kit on my car over the winter months here in Germany.My questions is that I was thinking of replacing the rods and Pistons but not the crank.If I did just those two how much boos would it be possible to run on an OEM crank VS. if I were to go ahead and do the aftermarket crank.

 

[euro_clipse]

Dood, you're crazy!! How was the races on the 22nd??? Wish I coulda gone. You need to pick up an Audi RS4, those things are so awesome!! Isn't our crank good to 350 HP's?? If so, just find a dyno and tune your boost on the dyno. Oh wait, you live in Germany, good luck finding a dyno!!

 

[EvuLFleA]

www.howellautomotive.com

sells bottom end rebuilf kits for $1100

 

[TotalEclipse112]

Thanks man good place for a bottom end.How much boost would that be capible of taking?

 

[green95hrcgs]

I have heard 15-17 psi on the street with pump gas and as high as 22-25 psi at the track using race gas. YOU MUST HAVE THE FUEL REQUIREMENTS TAKEN CARE OF TOO!

 

[EvuLFleA]

Ignition is a plus too

Fuel definately.

 

[TotalEclipse112]

So the OEM crank with new rods and piston accesories should be capible of taking 15-17 psi on the street with pump gas then?

 

[motofool]

the crank is not a weaklink in our motor the pistons and rods are...

eagle rods je pistons isa good setup use clevite bearings and a steel head gasket and you'll be fine upto 25psi or more with the supporting mods....and proper fuel....

make sure u get the journals polished good and everything machined by a expirenced shop...

 

[TotalEclipse112]

Thanks for the advice is there any specific compression pistons that I should run for turbo?Like 8.8:1 compression or anything like that?

 

[motofool]

for better tuning lower compresion is better, 8.5-9:1 is optimal

the higher the compression the smaller for window for tuning error is

if i was to recomend a shop to build your mild to decently built motor i would say http://www.advancedracingdynamics.com/main.shtml,

the howell kit is good but then u gotta do the work yourself or have a local shop do it...

if u want an evil motor talk to www.forwardmotion.com/phatridz.com

they build some really fast stuff like a 9.07 second 2.4litre neon...

Bill

 

[TurboRS]

The crank in the 420A is very well capable of handling all the HP you can throw at it... this aint no Honda.. if you go with pistons,rods, upgrade the injectors or go with the 8-injector set-up(info on it found at 2gnt.com), SAFC(if you decide to get big injectors), Crane or MSD ignition to retard timing( if running over 12psi), and a good Cm stage 3 or 4 clutch, you can run 15psi daily and 20psi with race gas no problem. ive ran this setup for about 2 years now, no problems. it takes WORK, so you better like working on little stuff all the time like all fast turbo cars require....but i enjoy that kinda stuff.

 

[TotalEclipse112]

What if I was to run 12.5:1 pistons with like 5-7 psi what kind of result could I expect to see with that?Or would I likeley blow up my motor?

 

[EvuLFleA]

If you have never rebuilt an engine, don't make a lot of $$, and won't be doing some serious tuning I would stay away from high compression and turbo.

Some people run 10.5:1 on 2gnt at 10psi and like it but more people blew there engines with anything over 9.0:1 compression than anything lower.

 

[motofool]

it is possible to run 12.5 questionable but the only peopl e running that our race fuel cars tuned for hours on end and running trick fuel/methonal etc 12.5:1 ina n/a car is a tad high for pump gas add boost and your way to high for pump gas if u havent built many motors stick with 8.5 or 8.8:1 and go higher boost....

the higher the compression less room to tune the car and less margin for error (meaning if its not right kaboom!)

 

[TotalEclipse112]

What would happen if I but 8.8:1 pistons without a turbo yet.Would it be sluggish?Or just not function?

 

[motofool]

it will run fine will feel like a stock car or so its not gonna have the power of a 9.5:1 or above car (n/as are 9.6:1 stock or so) slightly less power but with it being fresh u may not notice too much, it will function perfectly espeically on lower octane fuel because it has less compression....

 

[TotalEclipse112]

Cool then I can run that compression without a turbo.So does anyone know where I can get a steel head gasket for a 420A motor then?

 

[motofool]

the stock replacement mls gasket at mopar or mitsubishi is steel tti hasa head gasket summit had one etc...

 

[TotalEclipse112]

Thanks for all the help here I'll be sure to implement it as soon as possible.