I think I want a Crawl Box....

TURNEROFFROAD · Sep 7, 2011

Well I've decided a crawl box is in order, I do WAY too much crawling not to have a reduction box ahead of my 205. I'm running a Th400 and should have a pretty salty lil engine ( however MOST of my ponies come in after 3000rpm). I've got my 1.96 lo range in the 205 for shooting hills and want a deeper option for the slow stuff
Here's my question--

231 to 205 ( mmm. How strong y'all reckon the 231 is... Will it live behind 700+ horses???

203 to 205 ( that's a big box to fit in my lil buggy)

I have both boxes here and am just trying to decide if the 231 will live, be nice to have the extra gearing over the 203 however... The 203 ain't breaking

Elliott · Sep 7, 2011

If you've truelly got 700 horses your not going to crawl much without melting ****

TURNEROFFROAD · Sep 7, 2011

Elliott said:
If you've truelly got 700 horses your not going to crawl much without melting ****

Doing it through turbocharging, attempting to have it "all" in one rig... While certainly not STOCK below 3-3500 rpm. It'll be fairly manageable, it's kinda of my experiment on meshing a hill shooter with a crawler... We'll see soon enough, so what's the opinion on the crawl box????

stump jumper · Sep 7, 2011

Man I got a northwest fab black box behind my turbo 400. I really like it, it gives me tons of gearing, 1:1, 2:1, 3:1, and 5.44:1 But I use 3:1 90% of the time with my 4:56's.

Rockwells607 · Sep 8, 2011

I wanna see 700 hp in a rock garden! sounds like a bull in a china shop

TURNEROFFROAD · Sep 8, 2011

Rockwells607 said:
I wanna see 700 hp in a rock garden! sounds like a bull in a china shop

;D it does doesn't it... :woot:

98sierra · Sep 8, 2011

ive heard ALOT of bad about the crawl boxes..

wontwork · Sep 9, 2011

Your not gona be a able to crawl if its setup like mine. Mine keeps building boost after you let off and all i want to do is gas it. I have a ls1 with a vortec charger.

TURNEROFFROAD · Sep 9, 2011

wontwork said:
Your not gona be a able to crawl if its setup like mine. Mine keeps building boost after you let off and all i want to do is gas it. I have a ls1 with a vortec charger.

I'm not planning on ANY boost prior to 3-3500rpm. Should allow Me to crawl before I STAND ON IT!

98sierra · Sep 9, 2011

thats gonna be one bis ass turbo lol my integra that was boosted would start making boost at like 1500 (very small) but would hit super sexy hard at 3500. just make sure you have a motor that can hang on... with boost your allways on rev limiter.. kinda hard to stay put

TURNEROFFROAD · Sep 9, 2011

98sierra said:
thats gonna be one bis ass turbo lol my integra that was boosted would start making boost at like 1500 (very small) but would hit super sexy hard at 3500. just make sure you have a motor that can hang on... with boost your allways on rev limiter.. kinda hard to stay put

Idk how to post pix here from my iPhone or I'd show y'all my turbo setup :driving:

grcthird · Sep 9, 2011

I know nothing about a crawl box :****: but I'll derail the thread and ask if you are going to use a bypass(diverter) valve or a blow off valve? If you use a bypass valve your turbo should recover quicker between throttle blips and may help you stay in the power range a little better. Might make a difference with 700hp as to which gear you would use depending on what you are crawling. Just a thought. :dblthumb:

ETO · Sep 9, 2011

My turbo build is nothing near as wild as this one sounds like its going to be. I have a 96 vortec 4.3 on propane with one mid sized turbo wastegated at 8psi. To dump my boost when i let out of the throttle I used a blow off valve after my turbo so when i come off the gas it dumps all my boost and doesnt try to back spool the turbo and probably end up breaking the shaft.

xjpaddler · Sep 9, 2011

I wasnt able to get the pic to transfer, but I will try and put it into perspective. 3.8 motor( 14.9) turbo :****: turbo is bigger than the motor. if it all works as Ty has planned, it should be a nasty little mochine.

TURNEROFFROAD · Sep 9, 2011

Thanks for the replies guys, I guess I'll start a build thread soon on here

I'm running waste-gates and blow-off valves
Turbo specs are --

Compressor 71.75-108. Turbine 86-75

16 to 36cm exhaust housing (variable) titanium wheels and a billet shaft

120# injectors for fueling...

8.0 compression coated forged pistons
My cam specs- Stage 4 Turbo Cam, duration @ .050": 226Âº/218Âº, lobe lifts: .343"/.346", valve lifts with 1.60:1 rocker arms: .549"/.553", lobe separation angle: 116Âº, intake centerline: 110Âº

98sierra · Sep 9, 2011

kinda low compression if you still wanna crawl and make some power..

TURNEROFFROAD · Sep 9, 2011

98sierra said:
kinda low compression if you still wanna crawl and make some power..

With the gearing I have for crawling, lack of non boosted power shouldn't be a problem and with the lower compression, I got lots of room to put lots of air and fuel in da hole. The head gaskets and pistons good to 30ish pounds of boost... And I'm revving to 73-7500 rpm. Ought to GETTER DUN

1TONZR2 · Sep 9, 2011

I dont run 700HP, but I do have a mild 5.3 (cam/tune/milled heads) and I run the 231/205 behind my 4L60E and have zero issues with it. I have the chevy 32 spline input gear into the 205, so the crawl box has a pretty stout main shaft. I also put a 6 pinion planetary in it from either an early 231 or 241 (both were the same i believe). I have been running 42s on my truggy and have beat on it pretty hard. I run the 205 in low alot of the time, since I have 5.13s, but I have used the crawl box in low only. I really like the options that the 231/205 give me, compared to a 203/205. the weight is also a little lighter. I think one of the biggest failures is the case spliting apart, if it is not supported properly.

Brian