turbos?

[HVY84CHVY]

i have a 74 sb 400 in my 84 k10. i recently beefed it up a little and am looking to get a little more serious. the motor sits at about 425 horse right now and i am looking to get a little more umph out of it. i was thinking of going for a twin turbo application and was recomended to lean towrds a smaller turbo for low end boost and a larger tubo for high end. i am not looking for something to take to the strip and run a quarter in under ten, but a little something then will wake the neighbors and help me get the groceries a little quicker. any suggestions.

[bluechevelle]

U weren't very specific on what what you did to "beef" it up, but if you haven't, consider a cam upgrade and possibly some new heads before resorting to a turbo.

[HVY84CHVY]

sorry about that, to clear up what was done, before i bought it the previous owner put a weiand intake, edelbrock 750 carb, high volume oil pump, timing gears, high compression heads with 2.02 exhaust ports, bored .030 over. when i got my hands on it i upgraded the cam from from a comp .36 inch lift on intake and imlar exhasut to a lunati .42 and .45 lift and about a 215 and 216 duration, something close it forget the actaul numbers. open to any suggestions.

[Schister66]

On an engine that big, you have to be careful picking a turbo...you dont want something that's going to restrict you up top, but at the same time, you dont want something that's going to spool really late. You're not really going to have to "beef" anything up too much...unless you're planning for really big power...cast iron V8s are very stout and can handle a good amount of power. The lower compression also aides in keeping detonation at bay. If i were you, i would build a twin 60-1 setup. Those turbos are very effective, but rather inexpensive as well. That would be nice sized turbo for your engine....those turbos flow 61 lb/min and should be able to each support about 550whp. Together at low boost, you'd have decent throttle response and spool while still being able to make 600ish whp rather easily.

With the twin 60-1's you'd have a fairly streetable car that can also double as a fast as hell strip machine. Its all about matching the proper parts and learning to pedal through gears...lol. I saw that you wanted a sub-10sec car....that is possible on the 2x 60-1 setup i was telling you about, but there are better ones out there. The 60-1 came to mind because it is a good flowing turbo but it is cheap too. If you needed more turbo, you could step up to twin GT35rs or twin T4/T67's if needed...there are tons of turbos that would be good for your needs. One thing i would caution you against is having a small turbo and a large turbo. If you're hoping to run 10s or in that range, that small turbo is going to run out of steam and kill your power....it may make better midrange but will severely limit your top end. If you are serious about this, one of my close friends owns a business called Speed Trapp Consulting. They specialize in building and testing custom turbo units for various applications. Mac, my friend, is an engineer who worked for Garrett for 9 years. He now builds custom turbos for people ranging from street setups like mine to SFWD to straight up drag cars and so forth. He works with both Borg-Warner and Garrett. I can talk to him for you if you'd like to investigate your options a little more. If you'd like to contact him, you can call him at 248-792-4100. If you call him, tell him that Adam (schister66) recommended you...he's a great guy and really smart.

I'm not from the V8 scene, but the concept is all the same. If you build an efficient setup w/o half assing the important parts, you should have a reliable, fast setup. Make sure to get it tuned properly...i'm not entirely sure how that works on a Carbed engine, but for us fuelies, there are various EMS tuning systems available. Good luck w/ your project and if you have any questions, just PM me...i'm not the most V8 savvy person anymore, but i still know my turbos....check the sig :P