Too many choices, HELP RB VS L28

[acfitzzzz]

Hi All, Well I am finally getting close to building another Z. Now that the prices have risen 10 fold or so,  I figure I'll spend my money... LOL. This would be my 4th Z car. So, I am looking into doing a complete build on an S30, probably a 76-78, as I just cant justifying tearing up a 240 now that the values are through the roof. I am looking at a complete build, engine, tranny, suspension, brakes, etc, etc. I am thinking about a few different motor configurations. Ideally I would like to see RWHP in the 375 to 425 area, and torque somewhat commensurate with those numbers. I have thought about a NA motor, but not so sure I will see those numbers from an NA motor. As I hate turbo lag, but love the top end of a turbo, I was pondering a twin scroll type of a set up. My budget is in the $15K to $20k area for the motor. As many of you on this site have much more experience in this area than I do I would love to get some input from you as to what your thoughts are on this project and which way would you go, NA 3.2 motor, slightly built RB series motor, single twin scroll or twin turbo? Also, if I decide to go RB who is a good RB engine builder out there, I am in the Washington state area. I should add that I am not looking for a drag car, but something more like a solid GT car that can also handle some light track day fun. 

 

Thank you in advance for your input. 

Edited January 29, 2018 by acfitzzzz

[madkaw]

Hell- if you willing to spend that money , buy one of Datsun Works heads and something truly special

[30 ounce]

Getting that much RWHP out of 3.2 NA liters is going to be tough.  It will be a high strung high compression engine that will probably require race gas.  Going the turbo route makes things a lot easier but that is still asking a lot from 2.6 (guessing here as you didn’t state which RB) liters but completely doable and driveable but the RB’s I’ve seen making that much power have significant turbo lag. I also hate turbo lag but love the power.  I use to poopoo the idea of putting a V8 in the Z chassis but after seeing a few beautiful LS1 swaps and riding in one I decided to go that route and have no regrets.  It is so well mannered that it could be daily driven and power is instant, no turbo lag at all.  I have more torque at 2000 rpm than my 3.0 liter had at full song.  It put down 397 RWHP.  It’s addicting!  Maybe the Datsunworks head and twin turbos could get you there but your going in uncharted territory.  I’d do it if I had the cash!

Edited January 29, 2018 by 30 ounce

[acfitzzzz]

30 Ounce, thanks for the input. What do you think a well behaved, without much turbo lag RB25 or 26 could put to the rear wheels?  Obviously our cares are light so they don't need really a lot of HP ot TQ to move them along well. 

 

[mtnickel]

On 2018-01-30 at 4:05 PM, acfitzzzz said:

30 Ounce, thanks for the input. What do you think a well behaved, without much turbo lag RB25 or 26 could put to the rear wheels?  Obviously our cares are light so they don't need really a lot of HP ot TQ to move them along well. 

 

if you're willing to do a custom split pulse manifold and a high quality fast spooling turbo, you could do 400whp without much lag. Something like an efr7163 borg warner. Costs $$$ though.

[Chickenman]

Ball Bearing Turbo's spool so fast these days you can kiss Turbo Lag goodbye. A GT2871R will spool stoopid fast and should be close to the Power you want. Quite a few Autocrossers and Hill climbers out West use  GT2871R and there is no boost Lag,  Those are mainly 2.0 liter to 2.4 liter though. For over 3.0 liters you may want to look at a GT3071R,  GTX3071R Gen -11 or a  GTX2867 R Gen-II.

 

Lots of choices from Garret and Borg Warner.