On3 billet 84 thoughts
 

Is anyone running this turbo? What is everyone's thoughts on it behind a 5.3?

Interesting, I have not seen that one yet. Still has the smaller-ish turbine though.

I can't imagine it would make anything over their billet 78. That turbine has been a restriction since they crossed the 76mm threshold.

Have they released a billet 78 yet?

VS Racing has the billet 7875 now. Only a matter of time before On3 has the compressor housings cast with their name on them and starts selling them.

Restricted to what, about 850-900whp?

I have the 84mm coming tomorrow to compare to the 7875. I'm curious if it truly will spool faster as they say and flow a decent amount more. Honestly if it just flows what a PT7675CEA does for less then half the price then I'll be happy.

I ordered the 84mm because the cast 78mm wheel didn't seem to keep up in the higher RPM's. Most I could get out of it was spike 26-27psi and then taper to 21psi above 6k RPM. It didn't have the top end charge the PTE7675 CEA did as that would hold 24-25PSI to 7k easily.

Keep me updated

Did you have the cast or billet 7875?

On3 cast

In for results.

In for results :)

In that case, you should still see some gains from wheel weight alone.

Any idea on a time frame when you'll have a comparison?

What size motor/cam?

Long as weather holds should have a rental next weekend.


5.3L, 215/219 cam.

I love this, a real world comparison. Do you plan to put it on the rollers as well....or just compare the slips? I think you will be pleased with the new unit.

So I visited their website, and found a couple of things to be interesting. If they rate their turbos output at the crank, it definitely appears that they are sandbagging with the output numbers. They rate the 84mm turbo at 950.....but I'm using the 7876 and I'm making about 900 (crank) with a soft tuneup. I guess it's better to underrate...than to overrate. I also found it interesting that they are still using a .80ar compressor covet with the bigger wheel, seems they would have opened it up more to take advantage of the bigger wheel. Still seems to be a good value though. And found it even more interesting to see them using a Th350 in their test car....and running 9.0s.

I've never dynoed it, just made hits at the track. Hopefully it gains something otherwise just a giant waste of time. Trying to decide what to do for a longer term solution, I keep debating doing twins for a cheap higher power solution.

I'm planning on making the same swap in the spring. Curious to see your results

Subbed for the results. Would like to see how this will work.

In for results, my billet 78/75 just arrived. Curious to see your results

Comparison of cast 7875 to billet 8475:


https://ls1tech.com/forums/attachmen...0&d=1479228641

Attachment 557390

God that compressor is GORGEOUS!

Indeed! The blade length difference is huge, look at the hub diameter of the cast wheel vs the billet piece. I'm guessing it will flow a good bit more then the 7875. Hoping it will at least match the PT7675CEA, I will be thrilled if it exceeds it!

The turbine housing also seemed a touch bigger then the 7875, not sure if its just casting differences or it actually has more volume.

What did that sucker cost vs the 78/75?

Do you know the exducer size on that compressor?

Asking a lot of a 75mm wheel to turn that big sucker! What diameter is the shaft on that unit? Super common for the diesel guys to snap the shafts with big wheels and splits like that. Hope it’s awesome though! :nod:

They need to stick that compressor on the T6 Borg clones with the 87mm exh wheels.

~$700 shipped, so ~$300 more then the cast 78.

I had the cover off but didn't measure, it flares out pretty good but not extended tip.

On3 says the billet 84mm wheel weighs less then the cast 78mm wheel. They also say it spools up faster then the cast 78. I will keep an eye on my logs for comparison as the cast 78 was really quick into boost. Shaft appears to be same diameter on both.

Agree, even better wish they would do a billet 84 with 88/96 T4 unit for space limited guys!

Amen about us space limited guys.

I’d all about cutting big holes! If I can fit an LS and T6 in a tiny old mazda rx7 engine bay… you guys got no excuses! ;)

Agreed. Fbody engine bays arnt as small as people make them out to be. I could fit 2 borgs in my engine bay lol and I'm running truck offset accessories. Nobody wants to have to fab anything any more they want bolt on and go. (boring as fuck Imo)

;Not everyone has fbodys. But I've already fit a t6 Borg in my engine bay but couldn't route the exhaust anywhere that wasn't redicoulous for a family car. Smaller turbo with a smaller downpipe back to dual exhaust make going fast more livable. But if I didn't want to fab anything I wouldn't have done a manual swap... ;)

I know you don't have an fbody. I wasn't talking about anyone specifically just a broad statement that fbodys arnt as tight as they are made out to be.

That wheel looks badass.

VSRacing has a Billet 88mm based on their billet 80 borg clone. Uses a T6 housing. Will be out soon. ~$1000 for a 1600 HP turbo isn't a bad deal.

That’s cool, I didn’t know the S488 was on the way!




FWIW I just cut the goofy huge marmon flange off my VS racing S480. Then mig welded a 4” Vband on the housing. It literally dropped in place of my T4 setup and the old 4” exhaust bolted right up with zero modification. I did have to notch and box the frame in under it to get the turbo itself low enough to bolt up to my old existing hotside. Used a T4 to T6 flange from ebay and welded it directly to my old T4 flange. It was tight, but my existing drains and induction piping worked as well.

Attachment 594411
Attachment 594412

What did you use to cut the flange off the housing?

Sawzall with alot of oil. then a 4" grinder to bevel after.

Looking forward to the results. Mine is at my coater getting dipped in money and then the exhaust housing is getting ceramic coated.

Unfortunately I won't have it tuned until Jan.

Not bad at all!

Nice, ya I did the same thing on my S480. Certainly made it easier to mount, but getting a larger downpipe out of the engine bay is the problem. Might try some oval piping or just put some 4" in a vice to clear the steering shaft.

Also in for results. Planning on changing my GT45 for a 7875 but this billet 84mm is tempting. Unsure how my 5.3L LS6 cam will spool it being 6 speed now.

Jay

The 7875 is like a lightswitch with an M6. Even an S484 spools pretty damn quick with a manual. I see boost at 2100 with the 7875 and my friend sees boost before 3000 with the S484. You might be better off just jumping to the billet S480 and have best of both worlds.

Depends on which billet S480 you're talking about. The clone S480 has a very large turbine and isn't going to be the fastest spooling thing ever.

Assume clone has the same size as the larger FI units? That's with the big hotside, stage 3 turbo cam on a 5.3L. I think it spools pretty good for what it is, not as laggy as the T4 cast 88mm I had.

My stuff never spools this low. I think driving a tank might have something to do with the super low initial spool times you see! :lol:

I load mine plenty with a 3.25 gear 30" tire and 1.76 1st gear... Still, at 3000lbs I don't start making positive pressure till 3k+ on any turbo I've run. Small 1.10 t4 s476, S476, S480 etc... Of course if I'm on the trans brake at 3800 popping and banging I'm at 10lbs in no time... so that was never a factor for me... I tink I'd hate a manual trans in mine anyway.

You also run low enough compression that you could run mid 9s on 87 octane lol.

That was only the first engine with 8.6:1 it was a bit doggy out of boost. :lol: The 3 engines since were 9.5:1+.

2 tons of fun!

I just hooked up my two step and at 3500RPM and 35% throttle I can build 6-7lbs on jackstands before I glance over at the computer screen. Should get this pig going a little faster leaving on boost!

I can open my wastegate at 19 lbs with 2 step set at 3200 on the sloppy trans brake.
I wonder how the billet 84 would compare to my billet S475. Its starting to smoke, so I need a new turbo lol.

Ya auto is certainly more load and easier to build boost. I could footbrake as much boost as I wanted on the old setup, but much over 10 would blow the diff out.

Weather looks good so hopefully have some positive results Saturday.

Any luck?

84 makes more boost for sure... but couldn't get my clutch to hold it.

What clutch are you using?

One of the Monster LT1 twins that's been letting me know its not happy since the first track day it saw. I'm getting a McLeod RXT proven to work and hold more power.

https://cimg4.ibsrv.net/gimg/ls1tech...d4a95afd4d.jpg
https://cimg6.ibsrv.net/gimg/ls1tech...7f24e2fcc3.jpg
In preparation for the 400 today, this is what I found. Not trying to hijack, just wanted to share. Funny thing is this clutch STILL wasn't slipping. Shout out to Monster lol.

Loved my McLeod, flawless for years

You can upgrade the Monster to hold more power and it will cost less.:cheers:

In preparation for the 400 today, this is what I found. Not trying to hijack, just wanted to share. Funny thing is this clutch STILL wasn't slipping. Shout out to Monster lol.[/QUOTE]

That has seen some heat. Thanks for the post!!:cheers:

Any updates on this ?? Anyone else trying this turbo?

Really hoping for good results from this, has anyone else got one yet?

I'll be ordering mine this week

myself and a few others on here have used this turbo.I also switched from the 78/75 cast to the 84mm billet. I can say that the 84 mm shines in the midrange,and spools slightly faster. I havent had any issues with the On3 products,no shaft play after repeated abuse. if I had to nitpick then 2 things Ill mention. Seal the compressor side very well before use(both turbos) when received woulve had boost leaks if you simply bolt on and go.I used red permatex and cured 24 hrs before firing up initially. 2nd..the turbos are really quiet compared to other brands. having the filter on/off makes a substantial difference in both spool and sound of the turbo.

Other than that..good bang for the buck. Here is a dyno of the 78/75 on the dyno:

And here is the 84 billet on the dyno around the 6 min mark:

that looks different than my cast 7875........

Ya looks different than mine as well.

So what do your ON3 78/75's look like?

See this is where I'm at, I'm running a 7875 w/ a M6 and am trying to figure out where to go from here when I max out the 7875.
I'd like to go with a Borg or clone of some kind but wanna keep the fast spool for street shenanigans.
What were the specs on the S484 your buddy was using with his manual?

I went to an S480 after the on3 turbos and honestly couldn't tell much of a difference in spool, it stayed very fast. Both the S400's had the 88/96 hotside. I then went to twin 69/73's and still a ridiculous amount of power to use on the street, aka you better have full intentions of keeping it on the road when you floor it. I think a lot of it is in the tune as to how they spool with a manual, some people do it right and others have laggy turds.

They need to marry that 84mm compressor side with the PTE clone 88's 83mm/.96 t4 turbine. It would sell like crazy as a 84/83 as the 83mm t4.96 turbine housing is much larger than the "normal" .96 t4 for some reason.