98 gmc k2500

[Stumpuller454]

Finally got her running but i don`t have a throttle cable! ahhhh, I sooooo wish i could go for a spin, but heres a quick clip!

YouTube - supercharged 98 K2500

[James B.]

That was quick, nice work!
I'm going to bet you've got a throttle cable by tomorrow...

(The compressor you've got with that kit is a 1600cc Lysholm, hence the tiny pulley)

[Stumpuller454]

No unfortunatley i have to go out of town for work, so when i get back i`ll order a cable an slap it on... So there were different options of compressors in kits? If you say i have the 1600cc, then somebody has changed it up i guess, the instructions speak of the 2300, that seems like a big difference in displacment, Does this change anything on the tuning? will it still make the same boost?

[James B.]

The 454 can get away with the little compressor because the L29 shifts at a lethargic 4500RPM. The redline on the 1600cc Lysholm compressor is 15,000RPM. (It can do higher in short durations) The crank pulley is 7.5" diameter, so the blower pulley can be as small as 2.25" and not exceed the redline. The 1600cc compressor will make the same boost as the kit did with the 2300 compressor, there just won't be room to grow if you were to install a cam and valvesprings to make power over 4500. Belt slip is something you'll have to keep an eye on. The 1600 compressor is a lot easier to turn at 6 psi than a larger 2300 would be. 2.625" was the smallest pulley on the 2300 I was able to run making 9psi without slippage, for example.
I should guess that compressor with that pulley will make about 5psi on an L29 with stock valvetrain and heads.
I know there were some problems with the availability of the 2300AR compressor. Perhaps Lysholm discontinued it, I cannot remember. (The AR compressor housings have the larger 4-bolt discharge flange and the triangular duct casting in the top of the compressor for the smaller raised rear inlet port. AX housings have the back fully open, no triangular inlet cast into the top, and they have the smaller discharge flange intended to be bolted into from the bottom.) The only rear-entry compressors available now are all "AX" type cases, and the "R" type (top inlet) is available for use with carburetors or standard carb bolt-pattern inlet elbow adapters.

The 2300AR looks like this - (count the ribs between the front cover and the inlet ducting on the top, and take note of the "zero-drive" on the front of the compressor instead of the extension used with the 1600AX on the 454 kit...)

[Stumpuller454]

I must have the 1600 ax, my snub shaft is much longer, this kit bolted on without the use of the " injector spacer" which was kinda weird but great also cause then i didn`t have to make one...suppose thats the intention they had using the 1600ax instead of the 2300ar? then you would have to buy injectors also? either way this thing should work for me. Its great to learn all this stuff... keep it coming!! lol

Hey would you happen to know what HP and Torque numbers whipple got from this setup when they first released it? I figure i should be just a smidge better than there numbers... (: I have heard 150 hp, but was wondering exactly....

[James B.]

Well, this is somewhat pathetic, I actually DO have that information...
Horsepower was 416 compared to 281 as tested by Whipple.
Torque was 593ft/lbs compared to 398.

The stock ratings for the L29 at 290HP and 410ft/lbs.

I'm just another consumer, like yourself. Been a huge fan of Whipple's since the late 90's. I would love to see what the parts shelves look like in Fresno...

[James B.]

Speaking of stock ratings, I am on my FOURTEENTH month of blower withdrawl! I really miss the power, sound too.
This video was last month, stock 454+tuning only. It took water on slick concrete to do this and it never even shifted beyond second with the pedal to the floorboard the whole time. (sad, really)

http://bertok.us/pics/donuts.mpg

With the W140AX (2300cc) intercooled making 9psi I could do that on dry ground in third gear, but you'd never see it the smoke got so thick.

http://bertok.us/pics/burnout5a.jpg

Just imagine what a bigblock under twin screws can do...

[Stumpuller454]

Here isa quick 0-60 i did during lunch today, on cold rough hwy, accelerometer read 7.25 seconds, can probly bring that down under better conditions...

YouTube - Supercharged 98 K2500 454 (0-60)

[James B.]

You're never going to get tired of that sound - I can personally guarantee that!
Looks like it loses traction in first, grabs second, get traction and then downshifts back to first again, cool.