High compression RB20DET Build in progress

[TimeAttackTheory]

So I just got into my rb20det build and decided to share a few pics.

This is the car it's going in... 1995 s14

Jun auto extended crank collar. Oops I drilled a little too deep into the lower timing gear

































This is my means of transportation until the build is complete.

Modifications...

New oem engine gasket kit.ARP main studs, head studs, rod bolts, and exhaust manifold studsCometic MLS head gasket, and exhaust manifold gasket. CP Pistons 9.5:1 Compression ratioBlock and head has been decked raising the compression ratio to 10:15 angle valve jobSpool Austrailia conrodsACL HPC coated main and rod bearings Greddy cam gearsHKS timing beltClear timing coverFidanza 9.5lb aluminum flywheelSpec stage 3+ clutchNew oem timing belt tensioner, lower timing gear and rollerNew oem oil pump New oem water pumpJun auto extended crank collarq45 throttle bodyKnock off Jun surge tankMckinney motorsports downpipe and rad hosesNismo thermostatBlitz nur spec r exhaustCx racing fmic pipingGreddy m spec intercooler coreBlitz BOVTomei oil orificeThose are all the mods I can think of off the top of my head.

More pics coming soon when I have more time.
Modified by TimeAttackTheory at 5:52 PM 8/21/2009

[dtowngoalie]

What compression? What size turbo are you plannin on running?

[TimeAttackTheory]

10:1 compression. Im going to use garrett gt3076r turbo.

[DrifterProdigy85]

Nice. What kinda gas are you gonna be running? or do you just plan on boosting low?

[b00stinbmx]

nice! where'd u get the intake mani? i need one for my rb20 and that looks tits. its harder to find one for the rb20 i wish isis would make one for the 20 as well as 25.

bmx ftw

[Cjmartz2k]

Nice. I'm real interested to see how this does. I'll bet if you do things to keep knock threshold low, you can still run a lot of boost and decent timing i.e. water/meth injection, e85, water/air intercooler, etc.

[TimeAttackTheory]

Nice. What kinda gas are you gonna be running? or do you just plan on boosting low?

Im going to be running 93 octane with octane booster. You can actually run high compression and turbo on pump gas if tuned properly. I used to work for Audi and our 2.0 turbo engines come stock with 10.5:1 compression and to prevent knock, detonation, etc the ignition timing is constantly changed. Also the 4.2 audi rs4 runs 12.5:1 compression on pump gas and people have put superchargers on them without problems.

nice! where'd u get the intake mani? i need one for my rb20 and that looks tits. its harder to find one for the rb20 i wish isis would make one for the 20 as well as 25.

bmx ftw

The intake manifold I bought off some dude from connecticut for 400 bucks but theres intake manifolds that look just like this one on ebay made my a company called ku engineering. But the best manifold for an rb20det i've seen is from raw brokerage. A buddy of mine has one and its badass. I believe theyre on back order right now but talk to Ricky Roth and see if he can get any more of them. Ive bought alot of parts from him, good guy.

Heres a pic of one

[TimeAttackTheory]

e85 was another fuel I was considering. It's just hard to find places that sell it in my area. I used to drive a honda crx with 12:1 compression and I would mix vp c16 with sunoco 94 octane but they stopped selling 94 octane where I live so i'd have to use 93.

[Cjmartz2k]

You mentioned ocatane booster. I assume you're not talking about the stuff they sell in a can at autozone, right?

[TimeAttackTheory]

hahaha no not the stuff they sell in a can at autozone. I tried that before in my crx before I ran c16. To boost my octane I would mix toluene into my gas. 20-30% toluene 70-80% gas
Modified by TimeAttackTheory at 9:20 PM 8/21/2009

[StricNyne]

i got that intake on my car, its made by rbtally its the best ! here is a couple pics of it zer...ge=13

[Carl H]

nice, i wish i had gone with a higher cr for my rb20...i love the off boost driving of a high comp boosted engine and when on boost the power is phenominal.8.5:1 was the only cr available at the time when i put mine together.i'd say forget octane boosting gas, just tune for straight e85, keep ign relatively low and just make most of your power thru boost.should yeild a nice daily drivable engine with great power and torque, not to mention spool the 30r much faster.

[TimeAttackTheory]

nice, i wish i had gone with a higher cr for my rb20...i love the off boost driving of a high comp boosted engine and when on boost the power is phenominal.8.5:1 was the only cr available at the time when i put mine together.i'd say forget octane boosting gas, just tune for straight e85, keep ign relatively low and just make most of your power thru boost.should yeild a nice daily drivable engine with great power and torque, not to mention spool the 30r much faster.

8.5:1 was the only cr available during this build too. I had cp custom make these for me. These werent off the shelf pistons. The only problem with tuning for e85 is its very difficult to find in the philadelphia area.

[Cjmartz2k]

Toululene is good stuff

[TimeAttackTheory]

Yeah it is. I was thinking about getting it in a 55gal drum. But im going to look for a place near my home that sells e85 first.

[StricNyne]

in NJ philly is closest place to get e85 lol

[TimeAttackTheory]

Lol the closest place in philly for me to get e85 is center city. Thats a 20 minute drive from me which isnt that bad but what if im damn near empty and dont have enough gas to get downtown with all of the stop and go traffic.

[Fibre guy]

A 55 gallon barrel of pure toluene would be very expensive. About $1200 expensive.Not to mention it's used in MANY explosives... So buying that much for a residential address would put you under investigation.I'd stick with the e85 because its already blended and you don't have to source it.Awesome high compression build though!

[TimeAttackTheory]

Yeah I priced out a 55 gal drum for around 1100 bucks. lol yeah it would put me under investigation most likely. I would get it shipped to my shop then drive it home in my truck. But thanks! When it gets running i'll have videos posted.

[DrifterProdigy85]

Whats Toulene go for a gallon?

[rb25drag]

Nice build and good looking motor.

You wanna run high compression and alot of boost without knock. Propane fuel is your friend

There is some 4wheelin guys around me that have anywere from 13:1-15:1 compression on there buggies that run anywere from 15-30psi of boost with out a Problem.

Im at 9:6 on my rb25. I eventually plan to run 12:1 when I get the Propane fuel 100% Squared away.

Also as for Price. We had MPG set us up with a 500Gal tank and a fueling system at our shop. As long as its a Personal fueling center and not a Public fueling center you dont have to buy insurance. Also we get 500gal for around 800$ which averages out to about 1.29$ a gallon and thats rated at 110 Octain, I dunno if you guys haved priced race gas lately. But its up to 9.60$ a gallon around me. Ill keep my 1.29 fuel

Also having your own fueling system at your house would be most convenient

[Fibre guy]

How many miles are you getting to a gallon exactly?

[TimeAttackTheory]

about 15 bucks

[TimeAttackTheory]

Honestly idk what my mpg is or what its going to be once im done this build. My goal is 500hp so im pretty sure it's going to be a gas hog but im not concerened about fuel economy. That's what hondas are for

[TimeAttackTheory]

Thanks man and hahaha I wish race gas was 9.60 a gallon around where i live. Race gas is around 14-15 a gallon around here and our gas prices have lowered. Not too long ago 93 octane pump gas was 4.20 a gallon at this sunoco station near me.

[PorkChopExpress]

tagging along, i have a feeling your going to be kicking yourself later on for running 10 to 1.

[rb25det250sx]

you said 10:1 but your mod list say cp 9.5:1

[rb25drag]

I estimated my gas mileage on the propane last weekend when I drove it. Cruisen down the hwy I have it a little rich. 13.8 AFR Also I got on it prob 5-6 times and I averaged 15mpg. I think i can lean it out a little more cruisen and get 18-20.

That also was running a vapor from the tank. Im switching back to the liquid tank this week. Will see what happens.

Good luck on the build. Just remember on gas the higher the compression the less room for error! I hope you invest or already have all the tools to tune it and keep an eye on everything. Also hope you got a good ignition system and some COLD plugs.

[TimeAttackTheory]

The piston

you said 10:1 but your mod list say cp 9.5:1

Youre right but read the next line...

heres what I said "CP Pistons 9.5:1 Compression ratioBlock and head has been decked raising the compression ratio to 10:1"

The block and head were decked by the previous owner of this engine and I took even more material off the head myself thus making the combustion chamber volume smaller causing the compression ratio to go higher.

[Yellow4g63]

Stock cams? or do u have bigger? Nice build and nice rods