Jump to content
SAU Community

R31 Rb20Det Drift Car Help


Leeroy94
 Share

Recommended Posts

I have a R31 skyline running a stock rb20det from a r32 with a JJR dump pipe. Its running dual thermos on a stock aus spec radiator (fairly old). Just did a track day with the following problems:

Engine won't rev over 5500rpm.

Radiator gets way to hot, at one point the water temp hit 115 degrees so I had to take it off the track to cool down.

Before fixing the revs problem, we need to address the cooling. In what order should I diagnose this problem so that it is most cost effective.

I was thinking something like:

1) flush radiator

2) check water pump functions properly

3) replace radiator

Should I remove the thermostat? Is getting some anti boil radiator additive worth it?

All suggestions welcome as I'm new to working on cars.

Can post photos if needed regarding the engine.

Link to comment
Share on other sites

might seem stupid, are the thermos on the right way around? decent thermos can pump backwards and everything heats up real quick, especially whith little airflow going sideways.

Link to comment
Share on other sites

1. double check all your heater hoses that come off the block and off the thermostat housing, very common to have a pin hole and it only pisses out when hot and sucks air in making the car run hotter

2. hose rad out with water to confirm its not restricted from a blockage

3.remove and check thermostat that it opens in boiling water

4.check that water pump rotors ( behind the thermostat) move when you spin it by hand with the fan belt off

5.might as well flush rad due to age

6. bleed coolant repetitively

for thermo fans the best type is the 'S' bladed fans as they pick up the air in a proper whirl wind where as the straight ones just are crap

Edited by Dan_J
Link to comment
Share on other sites

Unfortunately i live in one of those neighbourhoods where the retiree's living next door call the police if we even sneeze. And my car has no exhaust so its pretty loud. I'll have to wait till Friday :(

Any ideas on why it wont rev past that amount? It seems to spit and run rough over the 5000 mark, loses boost too.

Link to comment
Share on other sites

It's definitely running rich.. I can smell the fuel from the cabin. And it has some sort of resistor plugged in to the injectors that makes the ecu think the engine is running cold so it pumps more fuel in or something :/

Link to comment
Share on other sites

For the heating side of things, first check the thermostat. Then check the radiator for cool spots. Basically, get the car warm and then run your hand over the radiator. If you feel spots that are cooler than other areas then the radiator is blocked and either needs replacing or the be professionally cleaned. Flushing the radiator does bugger all.

Link to comment
Share on other sites

It's definitely running rich.. I can smell the fuel from the cabin. And it has some sort of resistor plugged in to the injectors that makes the ecu think the engine is running cold so it pumps more fuel in or something :/

i had the low fuel rail preasure issue which is why i brought it up.

i could also smell fuel in the cabin which was the fuel return line or something not working right. this may be an issue if you can smell fuel.

coilpacks, fresh spark plugs, dyno for a propper check to see whats going on i recon.

  • Like 1
Link to comment
Share on other sites

It does this cold spot thing. So maybe I will give that a go. Do you thnk I should give it a go myself or just take it to a radiator place?

Take it to a radiator place, it isn't something that can be done at home. The cost of getting professionally cleaned may be close to that of a new radiator though, so it might be worth ringing and asking how much it will cost first.
Link to comment
Share on other sites

I've been quoted $280 delivered for a brand new aus spec r31 radiator. Is that a reasonable price?

Ill take it all apart tomorrow and take it in first thing Monday morning. Apparently they have a method of testing if its blocked or functioning fine at the shop.

Link to comment
Share on other sites

That's a pretty good price for a new genuine radiator mate, make sure you check the fan/shroud etc for damage.

After 25 years or however old the rad is, chances are it's going to be a bit rough. I'd recommend a new rad if you're hitting the track, for sure. Also hoses, thermostat etc. As bad as it is, I never used a thermostat in my R31 for the track (RB30).

Link to comment
Share on other sites

I've been quoted $280 delivered for a brand new aus spec r31 radiator. Is that a reasonable price?

Ill take it all apart tomorrow and take it in first thing Monday morning. Apparently they have a method of testing if its blocked or functioning fine at the shop.

From what I gather, often they just tip some water out of a kettle through the radiator and feel for cold spots (pretty much the same method I suggested)
  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share



  • Similar Content

  • Latest Posts

    • Little more work!  Did some body work on the rear wheel arches and since the paint was a cheap spray job before figured I’d do something to tide me over until I wrap the car.    Colour might not be everyone’s choice but I like it and it’s only temporary, just hate having primer from the wheel arches standing out.    Keeping an eye out for a decent set of wheels to throw on now. Wheels and tires on the car are junk
    • Its likely to be 70% road 30% track usage, track usage will increase if anything. Decided not to fit it as I cant be arsed changing the bushes on my LCAs again 🤣 I did get the below back from GKTech though so they should work together     The anti-squat kit and roll center adjusters work independently since they change the rear lower control arm's angle in different ways. The anti-squat kit adjusts the angle from front to back, which impacts anti-squat values. Roll center adjusters change the angle side to side, mainly to correct geometry on cars that are significantly lowered. They might affect each other a tiny bit, but overall, you can think of them as separate.
    • What are you doing with the car? street car or race car? People get hung up on the squat of the s/r chassis rears. There is positives to the squat if a car is setup and driven correctly for it (correct ride height, spring rate, alignment, damper valving). Generally just lengthen the rear traction arm by 5-10mm and that will help the squat and bump steer too. You are also correct with the roll centre too. This too also needs to be adjustable if you start messing with suspension geometry.   Having done quiet a bit of testing on race cars this year in regards to rear squat, I've seen some big positives from it in regards to drive off corners and traction. 
    • I find I am using the MX5 for everything except long overnight cruises with Jackie, or, if picking up the kids to go somewhere, the SS has so much more room inside, and is much more comfortable if your going to be doing Hwy driving for 6-8 hours And the MX5 isn't bad in stop go traffic for a manual transmission car, whilst the clutch kit has been upgraded from stock, it is still light, and also not having a stupidly light flywheel in it helps as well, I've spent alot of time sitting on the M5, M4 and M7 stuck in traffic when plodding around the Greater Sydney Region in it Another benefit is MX5's are not really a car that gets stolen, you can pretty much park it anywhere, and it will still be there when you return
    • I can totally get why you like it for that sort of commute. I was thinking BoganDore because it's such a lazy drive, for things like stop start traffic.   I used to do over an hour in stop start shit from one side of Bris to the next, twice a day. My choice of car was larger displacement, with an auto. Basically for torque in low rpm/very low speed, and no clutch pedal. But loved a fun manual for the weekends, which the partner has (plus had the LandCruiser too for other fun drives). I now have an EV as a work car, and I tell ya what, ultimate daily driver, especially if youre out of energy, like I often am after work. I don't even need to touch the brake pedal   That said, I'm presently rebuilding the Liberty GTB to get it setup for weekend drives and track abuse! So small high revving turbo engine with 6 speed cog swapper!   But for your style of commute, I'd probably take the MX5 too!   For those choices, I'm ignoring fuel economy. Because I know how atrocious V8 daily life is for fuel from when I used to daily a manual SS, ha ha. Hence why I know I love the daily rumble of a V8
×
×
  • Create New...