TxDiesel007

Runnin Rips twins i made the following observations today

I was pretty happy with them and i saw the following stats with my brother taking notes besides me, I have not had a chance to push them hard or play with them, but i figured what better time, and just went on with it, results were as follows..

max egts 1200 degrees
Max speed at WOT 100 mph at about 3000 rpms (slow i know)
Max boost: spike to 50 psi, then BOV's kick in and limit me to 46-48 psi, which is where i limited it to
Timing set 16.5 degrees
Fuel plate 100 full forward (for fun)
AFC position Full forward
Starwheel: completely loose
Injectors: 370s
DV's 181s (for now)
Turbos: 35/14 over an S400 no drilling thru gate, no other turbo mods either
GSK:4K kit, (free revs to 3800 easily, then kinda struggles to get to 4000 rpms)
Top turbo: wastegated to 24 psi

I came back with a 5000 lb load of hay and all i can say is that these things with a stock turbo uptop are built to pull, no questions asked. The power was there from midrange till about 3000 rpms, then the truck kinda falls flat on its face, BUT the egts are so nice and cool, i never saw speeds over 70 mph (right foot control) nor EGTS over 900 degrees, which for me was sweet in itself.... NO cooling system problems either so all was well..

For the future, after the headwork im looking at the following things, Im lookin at DDP4's, II delivery valves (Or scheids full cuts), more timing, an SPS 62/14 for the top of mine (or an s300, whatever comes along cheaper) next is headwork tho, then finally a valet switch to tame all this power im gonna have....

I was kinda dissapointed that with a stock HX35 even with the pyro pegged i could hit 100 miles per hour, why is it that with the twins, i can get cooler egts but cannot hit a higher top speed? Also why does the truck feel much slower afterwards? From 40-90 miles an hour it pulls like a train, and egts remain nice and cool, i dont think i have any boost leaks, or if i do its a minor one, then teh truck just goes splat, Perhaps i need more fuel and timing?

IN either case, just thought id share this with those of you contemplating a small twins setup....

DO IT!!

have a good one!

Rick

PS: If anyone has any tuning advice, please let me know, id love to learn more about my twins as well..

G1625S

I'm guessing the non-drilled 'gate on the little turbo is choking you on the top end pretty well. Plus, even though I'm not p-pump savvy, I'd have to think 16.5* is pretty conservative when spinning above 3000 rpm. My 12cm housing is absurdly hogged out (no center divider, yadda yadda) and I can keep things in check with my right foot with 5-7k behind me...with no intecrooler. I'm looking at putting a BHT3B under my hybrid when $$$ permits. Do you have studs?

TxDiesel007

Kinda thought bout the gate too,

No studs, IE the limited boost, and yup the 16.5 degrees is really hurting me, i think...

I think its time to drill thru the gate and snail...

Rick

12valve

i know you have a fp gauge! what does it show at WOT?

mine drops to 0 psi after 3000 rpm, and that's where it falls on his face also!

hmmm i still dont know why i didnt get more top speed after putting in a 4k GSK and with a bigger turbo i did!

is it the small turbo choking? might be...

12valve

also nice you can keep boost at the border of 50 psi.

i thought with a setup like yours and a HT3B you cant keep it as low, with the plate forward,

Am i right? your s400 makes less psi? but of course moves more air i guess...


what does your s400 alone show as boost? i know of a similar setup like yours, the HT3B alone made 37 boost. (2 much i think)

Teddy Bear

Perhaps an aftermarket cam would really help you out as far as making power above the 3Krpm range. My truck is the same way. It will rev to about 3800 really easy in neutral. But when driving, it kind of falls on its face after 3000rpm

TxDiesel007

Hmmm

actually i have a 4K kit in mine, and after messing round with it in neutral, it pops and actually seems like it misses, it will free rev to 3500 rpms a bit, pop, miss or whatever, then it will rev to 3800 or so and just stay there,

easy solution would be to just loosen the springs one click per say, BUT then my idle will randomly fall to 300 rpms, perhaps something else is wrong tho, i do have the springs as even as i can get them.

NOt so certain on the cam, im thinking more along the lines that i need more timing, and more fuel, im thinkin for my setup timing will have to be at least 20 degrees for it to run right, BUT since i tow with this thing, im very afraid to go over 18...

Leads me to the questions, why in the world is my IP popping? and second of all what effects will the cam have? i know its not needed till well over 600 horses, and i dont plan to go much above that...

Thanks for the input Teddy

Guys keep it coming

Rick

Mike Holmen

My HX-40 wastegate is set to 24psi. You don't want to go to high on your secondary turbo as your drive pressure will start to increase. It kinda defeats the purpose of running twins if your secondary is doing all the work. I would guess that your running out of fuel and might need to tweak your pump abit.

TxDiesel007

very seldom sees under 10 psi, so im not so sure, no offense, i dont get ur second statement, i think the top turbo is probably being choked out, i need to cross drill that thing, for now..

Rick

TxDiesel007

How would i go about tweaking the pump more?

I already have a full AFC, 100 full forward, and the starwheel completely loose? I know it needs timing, and my top turbo needs cross drilling, i know i need to do those two for sure..

thanks Mike

Rick

Muddin_dude06

Rick, I don't know a whole lot about the P7100 and it's internals yet but I know some people talk about giving it more rack travel for more fuel... Wish I could help you out more...

timbeaux38

I have seen the same setup you have go well over 5 bills with the right sticks and pump mods. (busted 12's too) I ahev seen a 40 on top make 740 with some sexy sticks and pump mods aswell.

alltimenomoney

So this is something I have been pondering for a while. Why couldn't a twin setup run an external wastegate around the small turbo rather than modifying the factory one. I would think (and I may be wrong) that doing so would give you way better control of boost and flow on the upper end.

Am I wrong or is it a cost thing?

Forrest Nearing

you're not wrong, it's an excellent setup. buddy of mine has a set of twins w/ an HY35 on top and an HT3B on bottom and has a big aftermarket gate going around the HY

alltimenomoney

Thanks for clarifying....have done lots of modifying turbo imports but this is my first attempt at diesels.....and I allready have two