scottyMIz

hey guys finally got the 300 rear swapped in and it works perfect, had to remake the rear toe arms so the bags would lift the truck. for those who dont know i have an rb25 already swapped in and has been dubbed skynoma

i swapped the rb20 into my sonoma and i loved it, The main thing is that the tq is low so off boost power is crappy with a bigger turbo, my truck is heavy so it made it worse. Stock form they have basically no lag but the turbo craps out on top end so i switched to a t3/t4, Once the turbo hit at 3500rpm the rb20 is very impressive as it pulls hard to 8k.I did break a piston or two in mine as they are weak and the only time it broke is when i had the haltech on it and couldnt tune it out because of the cas. I havent had my rb20 apart yet but i think another thing that the rb25 has and the rb20 doesnt is the oil squirters under the pistons (i could be wrong). I have since switched to an rb25 in the truck (it was only 500 bucks), i love both motors and would recommend the rb20 to anyone looking for good power at a low price. I am going to rebuild my rb20 and drop it in my 1967.5 SPL311, light car and that engine should be very good. One good thing about the rb20's head is that the exhaust manifolds are the same with the rb25. The rb20 along with any engine will make great power when built and tuned right, i wanna see more of the buiild on the rb20, and for 100 bucks? dang man send it to me

lol its ok raff i wanted the rb25 but i figured the 20 would be neat since i didnt have one yet. I did and still do like the engine but like you said the truck is too heavy. I didn't knwo it was so heavy til i weighed it after the rb20 was in. Im guessing its a ring or ring land since my compression is low on number 3. I have the pistons to fix it just gotta pull it apart and swap the piston and rod, then its going in the 67 roadster

well i broke the number 3 piston in the rb20 so for the bargain price of 500 bucks i got a rb25 long block. I finally got it in and runnin here are the pics and a short vid, sorry for the quality

ok the battleship has sunk here is the new look

here is mine same as jc's but they just have a polished lip, this is now i have 1.5" spacers coming hopefully tomorrow so it doesnt have the "battleship" look as racinjitter calls it fronts are 16x7's backs are 16x8's fronts are 15mm offset backs are 0 well worth the 290 bucks i spent on em

the rb25 should bolt right up to the engine and mounts, i love my rb20 i beat the crap out of mine and keeps coming back for more. Your new intake wont work on an rb25 unfortunately, all the bolt patterns are different on the plenum halves and head mounting.

i got the gear swapped in yesterday and the posi unit, the speedo is right on the money now 100kmh=61mph. The accelleration is much better in all gears 60mph is at about 2600-2700rpm but the vibration moved down to 60mph. I didn't go much faster than 55mph all the way home but it cruised great and i am sending the driveshaft to the driveline shop today. I have a new clutch coming hopefully friday and should have her back together this weekend. I am going to try and turn the boost up again too see if i can get a bit more out of it. Im thinking the tubing was closing when i had it up before, worth a shot i guess then maybe one more track day before the may 9th meet

over on nicoclub.com they have this discussion all the time, basically it's all up the the person doing the swap. They both make about the same power, sr weighs a little less, both respond good to mods. if you want to find out more you can goto nicoclub and look at their multiple discussions, most of the topics are old and there is alot of personal preference in them but there is good info there.All in all it's up to you and how much fab work you want to do.

I bought my rb20 from jdm engine zone in clifton NJ not sure if that is the same shop or a different one. If it's the same they are a good bunch of guys and tell them the guy with the rb20det powered sonoma says hi, the truck is running great!(they like my truck) When i did my compression test it was about 130 across the cyls the actual psi will vary depending on the gauge your using. My gauge is a cheap harbor freight gauge but the main thing is that they are very close in readings from cyl to cyl and that the gauge reads a reasonable amount.

well i figured out why the truck was blowing oil out at the end of the track. I swapped the t3/t4e onto the truck as i stated above but i noticed that the truck would fall on its face under full boost. It did it only when the truck was warm and at first i thought it was the wastegate til i saw that it was pulling vacuum when it would drop out. I got to thinking and after a few adjustments to the wastegate i figured out why it was falling on it's face and why the truck blew oil at the track. The inlet hose hooked from the turbo to the maf was getting soft and would buckle under the suction from the shock on the stock turbo, on the t3/t4e would pull it shut with the added power and suction. So i put a piece of tubing into the inlet of the tubing until i can make a custom one that i can route to the front. The moral of the story is i put the bigger turbo on for no reason........ well at least it does have more power

lol its ok jason, i was just gonna tell you about the run and that i got the t3/t4e on it now. Its laggy as hell but pulls good on top end, i think i need a smaller turbine housing a .48 would be perfect. the wheel hop and spinning really sucks in a truck, plus the weight of the old girl all in all it did do good.