Base91

iTrader: (1)

I'm trying to get going on a turbo set up for the 3.1 and have been reading a lot but have some basic questions. Also looking for feed back on the imagined set up.
1. Do the external waste gates need to be balanced in some way or should two the same be close enough?
2. Are both waste gates connected to the same vacuum source and controlled by a single boost controller?
3. Standard or lower compression ratio?
4. Standard or higher octane gas?
5. Which t3/t4 turbos? I see lots on e-bay with different trims and very wide range of prices (I'm thinking the $100-$150 range). Anyone recommend a pair?
6. What size intercooler? The biggest I can fit? Are the horsepower numbers given in the ads meaningful?
7. I'm thinking about having 1.5" dump and 2.5" down pipes merged into twin 3" collectors around 18-24 inches from the turbo. Good set up?
8. Then dual 3" pipes to free flow mufflers exiting before rear axle. OK or too loud? Don't want to attract wrong attention and track has 95dB restriction.
9. What size blow off valve?

Sorry for the question dump but if I want to know I'm sure others do too. I understand that the answers to some of the questions may be dependent on what boost level is wanted and the rest of the engine set up etc. And I know there is a lot more in the way of sensors and tuning to do. My approach idea is to build the system and get it all working on the stock 3.1 with minimum boost so I can learn how and what to do then work on improving the engine set up when I have some higher level of competence/confidence/cash. I have a 3.4 block to rebuild (first time) plus 3400 heads/intake etc. and I've already got headers, waste gates, boost controller and BOV. So the end game, one day and in stages, would be a strong hybrid 3.4 with a decent level of boost without having to redo the turbo hardware.

Thanks if you got this far and will appreciate any help and feed back.

Orr89RocZ

iTrader: (20)

Same size gate on each bank preferably in similar location on the feed pipe before turbo inlet. Vacuum ports on gates T into each other to a single line to manifold or boost controller reference.

If you are making headers or logs, use small header pipe, probably dont need to be any larger than 1.5" into a log section 2". 2" to turbo is more than enough. 2.5" downpipes are fine all the way back. Dont need to merge them into any 3" piping. Can install an h pipe or x pipe in the dual system say in the stock cat location

Base91

iTrader: (1)

Great start. I've already got the headers thanks to bl85c. Is merging the dump pipe back in to the 2.5" pipe 18-24" OK? Good thing about the 6 no balance pipe needed!

Orr89RocZ

iTrader: (20)

You talking wastegate exhaust pipe back to down pipe 18-24" downstream from turbo? That is fine and will work great. Just T it into the downpipe. If you arent looking for over 500-600hp dual 2.5" will work. Dual 3" will work to 1000+ even tho 3.5 or larger is better. I just suggest 2.5 on yours because its cheaper lighter and easier to fit under car.

Base91

iTrader: (1)

2.5 inch it is then. If I can ever afford to go to 500+ hp I'll spring for bigger pipes.
Anyone recommend which turbos?

anesthes

iTrader: (12)

How are you going to build this in California? Won't the smog folks hall you off to a fema camp or something?

-- Joe

Base91

iTrader: (1)

Very discreetly. And I won't tell anyone and it's why I want it to stay pretty quiet. I just got the smog done so I've got a couple of years to play with it before deciding it's track only or put all the stock stuff back in for the test. Then take it all out again. It's a part time run about but I use it for auto-x and hopefully some track days if it doesn't blow up. From what I see at the track I'd guess a large majority of the street driven cars aren't smog compliant. So it's fingers crossed and hope the gestapo is otherwise engaged!

Beater79TA

Not sure which group you autox with but in SCCA, the addition of turbos to a non-turbo car automatically puts you in the XP division.

Base91

iTrader: (1)

Local club. SCCA is too far away, too expensive and too few runs.
Any e-bay turbo recommendations?

project89

iTrader: (1)

iron heads?

u want a pair of t3 50 trims, with the smaller .48 ar turbines
for auto x i personally would have went single turbo a 66mm compressor with a stage 3 turbine in a .48 housing to get that big wheel moving tons of air at low rpm

also put the 252 cam in it not the 260

a pair of disco potatoes may work well to ( gt28rs )

Fallen2603

A couple K04 turbochargers could be an option, too. They're probably a little more expensive, per turbo, than a lot of the other eBay types. However, they have internal wastegates, so you wouldn't have to spend money on two wastegates.

Ross1713

I am subscribing getting ready to do they same thing ,but not sure about using 3.4 heads

Ross1713

can you put turbos down stream like close to rear wheels like the vettes also is it possibly to keep the turbo super quiet would like to keep a sleep like apperance

Ross1713

I have a question, I know absolutely nothing when it comes to turbos, but these turbos listed the pair of gt 28rs, the ko4, the t3/t4 50 trims .48 turbine I know these are recomended for v-6 but if I decide to go v-8, can I use the same turbos? I will just have to play with boost?

I live 30 miles east of cleveland, Ohio In Painesville if anyone wants to stop by