Prodigious

Does anyone have any recommendations for a mostly stock L98 budget turbo setup? Preferably a single turbo low boost setup, probably around 8lbs. And how much power this would pick up? My L98 was rebuilt about 100k miles ago, but it was bored .030 over and given a mild cam when it was rebuilt.

Orr89RocZ

iTrader: (20)

On3 t61 or t70 would do well. Front mount .96 ar exhaust

8 lbs should pick up 60-80 hp i would guess but hard to say for sure. I'd have to run the numbers

Prodigious

Okay, that sounds pretty reasonable. How much do you think a whole turbo setup would be? It seems that a t70 with a .96 ar costs around $300, and that leaves the wastegate, intercooler, plumbing, and fabrication right? I'm fairly new to power adders as a whole, but I'm guessing bigger injectors or higher fuel pressure would be needed as well? I'm sorry for so many questions, but I do believe that you're one of the most knowledgeable members on this site about turbos.

Cost isn't TOO much of a factor with this setup, but cheap is always better, as long as it's still good.

cheesehomer

iTrader: (2)

I find that very confusing with such a difference in wheel size
61mm to 70mm.
Please explain


Thanks George

Orr89RocZ

iTrader: (20)

On3 make those two sizes plus a 76. The 61 would do 350-400 hp easily and comfortably. T70 400-500 easily. T70 is very popular and available so you may find them more often for sale by vendors and classifieds. I put a 70 on my 305 because i got it new for 280 shipped. It spools fine and is abit overkill for what i originally wanted but leaves room to grow

All depends on what you want motor to do and how much you wanna spend. Just throwin out options of whats best bang for buck available

Step up would be borg s366 for 550-600$. Its a lot larger frame tho and makes packaging alittle more difficult. Gt45 also is available for 300-350 ish from vsracing. It will do 600-650 hp so its overkill on stock motor but leaves room to grow
Turbonetics hurricanes are great. 6265-6668 would be great too

cheesehomer

iTrader: (2)

[QUOTE=Orr89RocZ;5970640]On3 make those two sizes plus a 76. The 61 would do 350-400 hp easily and comfortably. T70 400-500 easily. T70 is very popular and available so you may find them more often for sale by vendors and classifieds. I put a 70 on my 305 because i got it new for 280 shipped. It spools fine and is abit overkill for what i originally wanted but leaves room to grow

All depends on what you want motor to do and how much you wanna spend. Just throwin out options of whats best bang for buck available

Is the main goal to find a turbo that spools at the correct RPM for the motor size and condition of use, track vs Street ? .
I would think that for track use, the turbo would spool higher and street the opposite. Correct ?
In that case, how does your t70 REAR mounted turbo spool easily ?
What RPM does it spool at ?.
Thanks George

Drac0nic

A lot of the turbo choice depends on use, engine and power train choices. The more flow into the engine required the more flow out from the turbo you'll need. If I had an auto or manual and no plans to change the converter or engine, I'd lean small. You're only using a narrow power band in a drag application (road race applications are another animal) so having a high stall speed to bring the RPM up quickly, then a bigger turbo that needs it is okay. Naturally "streetable" is a super subjective term as some people believe it's driving whatever doesn't get the cops pulling you over. Even if you're doing something that's more dedicated track it's possible a smaller turbo works better for the reason that you get more area under the HP curve due to a faster spooling time.

Something I don't see in your list is fueling and ability to tune. I'd consider that strongly before I took the plunge on a forced induction system. It's something I would definitely have in order before I started bolting a boost generating device on.

Galaxie500XL

iTrader: (1)

Drac said pretty much what I was going to, with one addition...


There's really not such a thing as budget forced induction--those corners you have to cut to keep costs down usually mean picking up the engine with a broom sooner or later, accompanied by sharp, stabbing pains around the wallet.

Orr89RocZ

iTrader: (20)

[QUOTE=cheesehomer;5970649]Eh sorta. Imo, You want turbo to spool near peak trq rpm and carry strong without restriction to shift rpm. You'd use a trq converter that stalls near peak trq as well. This will be a strong running combo at the track but also street.

Some guys for street only may like quick spool and more instant response. Tend to size slightly smaller and then see some restriction at high rpms aka backpressure.

My t70 rear mount was spooling 2 psi by 2300 rpm stock 305 motor. With cat converter still on. When i gutted that it ruined exhUst flow and heat now doesnt spool til alot later but wot downshift it goes to 5-6 psi instantly and within a second goes to set level of 10. I will be straight piping the cat area and see if i cant get that back

1988CamaroSC

iTrader: (2)

exactly

Orr89RocZ

iTrader: (20)

Doin work yourself in stock motor, the cheapest your gonna make out will be roughly 1500-1700$ depending what parts you use and where you put things and intercooler

TurboedTPI

One of the most important things here is picking the right combos. My car with a 3000rpm stall, 3.23 gears, and the turbonetics 62-1 (1.0 exhaust housing) I had was a killer combo. That was a combo that was hard to beat on the street. But with my build, I was maxing the turbo out. Im actually really surprised it made the power it did with that little turbo. I honestly think the 62-1 or similar sized other turbo with a 2800-3000 stall is ideal for stockish TPI cars. Just my experience tho.

Linson

why go "rear-mount" or "remote-mount" vs. "front mount?"

seems like it might enable you to keep your headers intact, but i can't think of a logical place outside of the engine bay to install a turbo on a Third Gen.

cheesehomer

iTrader: (2)

How much of a difference would there be for a 5spd with the same combo ?

Orr89RocZ

iTrader: (20)

Its the easiest place to mount a turbo. By rear tire frame rail, you can keep stock manifolds and exhaust or shorty headers and oem style catback/ypipe and run it to turbo. Very little fabrication involved on hotside. But you do have to have a good bit of cold piping and also oil scavenge pump which isnt cheap.

Getting cold side past engine k member also can be alittle tricky.

But nothing in engine bay needs changed. Rad stays same, ac stays there, all emissions stuff, coolant reservoir etc. all stays same as stock. Getting turbo up front can be alittle more difficult

anesthes

iTrader: (12)

Run the cold side through the passenger compartment

-- Joe

Linson

that all sounds pretty intriguing.
if i'm not mistaken, you are doing this on a Camaro, right?
how are you fabricating it? and how is your progress?

Orr89RocZ

iTrader: (20)

Lol its been done and running. Just not quite making the power i estimated yet but i need to regap the plugs, wrap the exhaust and straight pipe the cat, and retune. Cold side hangs touch lower than i like for the roads around here and i do plan on rerouting it but for now its working great.

TurboedTPI

I'm not too sure. I'd imagine you'd have a slower spool, but how much slower, I couldn't tell you.

Prodigious

Thanks for the replies guys, and I actually did ask about the fueling in my second post, but I completely see what you guys are saying about there not really being such a thing as a budget setup without risking more expensive things later on. However $1500 to $1700 doesn't really seem to steep at all for the power that will be gained, especially seeing as a procharger will run you $5k or better.

Orr89RocZ

iTrader: (20)

That can easily stretch to 2-3 grand so be careful. Its the small stuff that nickels and dimes the build and drains the budget haha

anesthes

iTrader: (12)

My on3 76mm build was kinda cheap. Lot of Chinese stuff. It's the supporting things like ecm, stout block, injectors that are big ticket.

I think for under $1200 the Chinese single turbo stuff works fine for a L98. The only reason I had to modify mine was the afr heads. It fit stock beads fine.

Orr89RocZ

iTrader: (20)

Yeah i guess if you the china single turbo manifold which i am not a fan of. I dont like how the crossover tube joins and dont like the wastegate tube location.

But its not always the major parts that add up. Silicone couplers and tbolts can be couple hundred bucks depending how you run hotside lol. Vbands, oil lines, etc.

My rear mount i have maybe 1600 into it with a stock motor and exhaust. Could easily grow with more fabrication

sailtexas186548

iTrader: (2)

The hotside/turbo/waste-gate and intercooler/bov are the cheap (using Chinese parts) and easy parts of a turbo build.

Beyond that, on a well built setup you will spend more on the supporting systems like fuel, heat control wraps/blankets/coatings, various lines, battery relocation, intake/filter, crank case evac, tuning gear, fittings, flanges, bolts, gaskets, sensors, couplings, than you will on the turbo setup. I learned this lesson when I built my car the first time, I finished the "turbo kit" and started it up, only to realize I was only half way done!

It seems like a lot of people seem to miss the fact that the only reason turbos are "cheap" is the hot-side/waste-gate/turbo/tubing can be fairly inexpensive and built without to much fuss. Once you get that sorted out you realized how much more you still have to do to make it run "right". Sure it can be done really cheap, especially if you have experience and access to tools and a shop with spares/scraps laying around - but that's not going to happen on your first attempt at it.

Orr is a great example of this, he has a built, 8 second turbo third gen and a rear mount 305 that he built after he built the 8 second car. Starting with a bone stock car in good shape, he has tons of experience building turbo third gens and is in it $1700 with a rear mount (not counting the tuning gear), and he's the first to say it's not really done yet, he's still fighting the little things.

I think a $2500-$3000 budget is a good starting point if you plan on going with a low budget setup for a stock car.

anesthes

iTrader: (12)

With the s-trim I was running 12lbs for a few seasons without an intercooler. This is around 72% efficient. If you size the turbo appropriately you should be able to run the same.

8psi with an intercooler sounds awfully anemic.

-- Joe

Orr89RocZ

iTrader: (20)

Math works out to closer to 100 hp on 8 psi but if motor is tired and old, it may not like the boost and suffer some blowby losses. May not make the power.

I still need to play with my 305 to verify how much power it makes with 9-10 psi. It clearly aint making what theoretical numbers say it should

tmellott89

my 350 is forged bottom end but still standard bore. stock tpi with l98 heads they have been ported and with 2.00 valves though. cam is small .470/.490.old slp grind 36lbs. injectors. the paxton pushes only 5-6 psi @ wot no intercooler but 50/50 meth. ive went few 12.60s and alot of 70s. never dynod but the car weighs 3570 with no one in it. ive used online calculaters and they estimated around 430 flywheel and 350 at the wheels. it has the right gears in it just needs more converter as it sits. just to give a comparison. mabey it will help out. i figure N/A the motors around 300 or so at the flywheel.