anesthes

iTrader: (12)

I've recently been experimenting with XS-POWER/SSAC Chevy turbo header "KIT". This is the cheap ebay one, that goes for $210 shipped. It comes with a turbo header with T4 flange, driver header, crossover and gaskets.

While this "KIT" requires some modification for use with raised exhaust and angle plug heads (like my AFR 210s), they seem to fit straight plug L98 heads just fine.

The driver side header fits perfectly, with tons of room.

The crossover fits properly, but requires a small starter.

This "KIT" is a knockoff of the BBS turbo header commonly sold on here. I have not actually ever seen one in person, but I've seen a lot of pictures. What I can tell you about the knockoff header is that the weld quality is good, they are made of 16 guage stainless steel and are quite heavy duty. The flange has 1.75 x 1.75 square ports, welded and ported. I've spent a lot of time cutting/welding on mine and it appears to be quality materials. The driver header is 1 5/8" tubes, but D shaped ports. Both have 2 1/2" collector/crossover. The crossover is also 16 gauge stainless. Some have reported that they may crack under stress. I opted to weld a 2 1/2" flex on my crossover.

Will not fit cars with A/C. I cut up my serp bracket the same way Street Lethal and others have done. If you want A/C you will need to use VBELT or move
the T4 flange.

So I wanted to share what I have learned, and put together a very short list which should technically make a 400-500hp L98 with turbo.

Again, this is a list for a STOCK L98.


1) XS-Power turbo headers: http://xs-power.com/gm-turbo-manifolds-3.htm $210

2) GT45 turbo (T4 flange). As of 1/7/2014 these are going (free shipping) for $244

(CR Racing sells the above mentioned headers, this turbo, a 38MM wastegate, oil fittings and -4 hose for $498 shipped - this obviously saves about $100)



3) T4 1/2" NPT drain adapter. $10

4) T4 oil feed adapter with -4 male threads $10

5) 36" -4 oil hose $40

6) -4 to 1/8" NPT hose fitting, $8

7) -4 female to -4 male 45* fitting, $12

8) Two 1/2" NPT to 5/8" hose barb $10

9) Two feet 5/8" oil/trans hose $6

10) THREE 45* 3" pipe bends $48

11) Two 3" x 4" stainless flex adapters. $38

12) 3" Vband 'kit' $14

13) 4" air cleaner, $22

14) Adjustable TIAL type BOV $30

15) OBX 7:1, 10:1, or 12:1 FMU $103

16) Misc fuel hose barbs for fmu $20

17) 38MM WG $55 shipped

18) A 1 3/4" U bend, and some misc 1 3/4" pipe for WG $60

Total: $950-975

Additional items needed:

Silicone adapter probably 90* 2.5 to 3"
Tube with BOV flange
Two 90* aluminum tube
Two or more 3" silicone couplers
3" to 4" 90* silicone adapter for throttle body

or a cx-racing intercooler kit, sawzall, and a few days to plumb it together.

Oil drain is fed into the fuel pump blockoff plate. I welded a 1/2" NPT nut to the plate (after drilling a hole) so I could screw the 5/8" x 1/2" NPT hose barb.

If you don't have the ability to weld, I don't know how you're going to fabricate the downpipe and merge it into your catback. I started off using my MIG, and got about halfway through. I switched to the TIG and the welds come out a lot better (on the stainless specifically). A mig will get the job done though. It costs 80 cents per day to rent a 60 cu/ft cylinder of tri-mix. Use that with the mig and 308L (or 304L) wire. Don't try using straight argon like I did, leave that for the tig. Return the cylinder when your done. You only need about 70 amps to weld 16 gauge stainless, so even a cheap mig will work just fine. Again, we're not talking chip foose quality work - we're talking cheap effective DIY turbo.


For guys with built engines, here is some things I ran into:

1) On angle plugs the #8 primary crashed into the plug. I cut off and re-routed my tube.

2) Raised runner heads (AFR, world products, etc) because of the raised exhaust port on both sides the crossover geometry doesn't quite line up properly. I cut the crossover above the starter and welded a vband flange. I then cut the crossover on the other side, cut off the 3 bolt header flange and welded a stainless flex and vband. I tucked the crossover CLOSER to the oil pan for ground clearance.

2) Wastegate position shares the #2 primary I opted to re-route my #2 primary into the log.

3) T4 flange is high and next to valve cover. Two problems here. A T76 just barely rubs the hood brace on my formula. I suspect that's also due to the raised exhaust runner. But this also means a T76 (.96 A/R in my case) is about as large as you can fit. A 1.15 A/R is exactly 1/4" taller, so perhaps on a non-raised runner a 1.15 A/R T76 would work as well. No T6 turbos. Also, the T76 crashes into the valvecover slightly and required the assistance of a BFH. I'm running tall valve covers, so again on a stock L98 I don't suspect this to be an issue. This is very eas to modify.


Realistically, this is a fantastic list of parts that for around $900-1000 you can bolt onto a stock L98 and run 12s or even 11s. If you blow it up, you buy another L98 for $300.

-- Joe

project89

iTrader: (1)

the gt35 turbo is to small for a single on v8 be it a 305 or 350 , the compressor will move enough air but the turbine wheel is much much to small

for the budget build one of the ebay gt45's or ebay t70,t72,t76's will fit on that header and be a much better choice for around the same price to 75$ more then the gt35
the 38mm gate should control boost just fine with either turbo on a stock l98 or 305 tpi


btw i have gt35's on my iroc , they work great as a pair of twins

also the greddy style bov is a piece of junk , as are most of the diaphram ebay valves , what u want to get is one of the piston types , the tial copy or the rfl copy, i prefer the rfl copy as they are 30$'s each , just be aware when the rfls open up they are friggen loud. rfl = Really friggen loud , thats how they got there name actually

if u want something quiter go for the tial copy


other then that ur list looks pretty solid

anesthes

iTrader: (12)

Edited. Thanks!

I'm using a real greddy BOV on mine, so I assumed the copies would be ok.

I think fabricating the WG dump into the downpipe is what turns a lot of people off, due to the location of the WG flange on the BBS/xs-power/ssac header.

Otherwise, I mocked it up on a stock L98 and it fits like a glove. I can't believe more people are not turbo on this forum.

-- Joe

project89

iTrader: (1)

the diaphrams in the greddy type and few other type of knockoffs either leak , or rip after a lil bit of use , its really hit or miss on those .

the piston type ones dont have anything to rip or tear its just a sliding brass valve in a sleeve with a spring , they just need to be greased once in a while ( once a year) takes all of 2 minutes to do

92g92

Hmmm I'm just a little confused by what you mean when you say "the waste gate dump into the down pipe." I have experience with turbo cars but I guess I'm having difficulty picturing what you mean by this. The waste gate as far as I know is before the bov (in terms of airflow from turbo to intake) and is just welded onto the piping? I've always thought of a waste gate as basically a bov that opens under a set pressure to ensure a certain psi. Educate me please, if you will.

Jay_rich

iTrader: (4)

Wastegates go pre-turbo on the exhaust to control exhaust flow, therefor controlling "boost".

Blow off Valve or bypass valves go on the cold side to the intake. Bypass valves are whats on most factory cars. Similar concept to the BOV but bypasses the air back into the inlet of the turbo.

Jay

scamaro355

Ill try anything once.. Twice if its fun