L28 ET project

Zed2k

Well-Known Forum User
I already have a bigger rad and oil cooler, I have just been cutting holes in my front spoiler to get more air to the oil cooler, the cars not over heating, but fuel getting hot and the pump gets noisy, can't believe you haven't got and oil Cooler, bad boy, I'm going to lag the fuel lines and put vents in the bonnet down the turbo side of the engine, I too have 2 fire extinguishers to hand, when i get my grp bonnet from Ben I'll work out the best way to extract the hot air from the engine bay.
 

twoforty

Well-Known Forum User
I cut my vents into the bonnet today, I have extra oil and the sump is a good heatsink with fins on the bottom for cooling. I know it's not as god as an oil cooler but it's fine for road use. Why is your fuel getting hot? do you have s swirl pot? I T'd my fuel rail return and swirl return back into the same line then back to the main tank. I think my Rad is mounted to low for starters...how high above the rad support should the rad be say if measuring from the top of the rad cap to the rad support.

Thanks
 

Zed2k

Well-Known Forum User
Here's a photo of how my rad sits, I have a Facet pump filling a 1litre surge tank, then a 10mm feed to the bosch motorsport pump mounted under the rear floor, this supplys the engine then the return goes back to the swirl pot, and then an over flow goes back to the tank. the surge tank is mounted near to the tank with plenty of air so not sure why the fuels getting hot, never mind will get it sorted..:)
 

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Rob Gaskin

Treasurer
Staff member
Site Administrator
My 240 is very mildly modified compared to yours but with a standard rad and no cooler overheating/low oil pressure was a problem.

Had my rad re-cored with a triple layer, high efficiency unit and fitted an oil cooler, since then it's been fine. I use the standard viscous fan which I like.

Simon I did know what the hissing was by the way. As a matter of interest where in the rev range is your power produced. I have only ever driven one petrol turbo (bottom of the range 260bhp Evo 9) and it was quite unsporty in it's engine characteristics i.e. all in at about 5,500. It went well thought!
 

twoforty

Well-Known Forum User
Yeah mine is a little lower than that, not sure if that would cause problems with air blocks. Maybe you fuel is just flowing arond the rail back to the pot then back to the rail in a heating cycle....thats the main reason I sent mine back to the main tank.
I'm goint ot pull out the IC and cut out the diagonal support in my rad support frame, then I'm going to make sure its all sealed up and duct the whole thing in a box. Oh and get a new lower hose, mine is very soft and may be collapsing under suction.
 

twoforty

Well-Known Forum User
My power starts really low down and max torque by 3500 to 5000rpm....I didnt rev the car much past 5.5k on the track and only had the bost set to 10psi for fear of cooking the engine....there is no lag to talk of and pulls like train from 2500 upwards. If we get time I'll let you take it up the road at japfest.
 

240z

Club Member
Looking great - glad your test day went well, can't wait to see it out on track on Saturday. Let's just pray for good weather!
 

twoforty

Well-Known Forum User
Thanks Phil....yeah it's going to be fingers crossed with the weather...no real point taking my car round if its raining :(
 

Zed2k

Well-Known Forum User
It'll just be a who can spin in how many gears comp!! Standard clutch started to slip last night, it's the first time i really pushed the engine, it really goes well, have to be carefull with the clutch on saturday.
Surge tank getting hot from the rear wheel I think might have to sheild it or move it further in board. Also going to fit cold air induction system. no before the weekend though..New clutch in them up to the Pod me thinks!!
 

twoforty

Well-Known Forum User
Yeah right, I can spin 1st 2nd and 3rd in the wet without too much trouble :( I will probably give it a miss if it's wet for fear of some fool crashing into me.
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
Simon, if it's wet turn the boost down and take your time, it'll be good training in car control. Get 'Racer' to go out with you.

Also your car will stay cool (even if you don't fighting opposite lock inside it).

Anyway It'll be dry :thumbs:.
 

twoforty

Well-Known Forum User
Finally got the car in a state where it would sit on the dyno without any problems. I didn't get as long as I wanted on there but it was interesting to see what an old l28 would do.
As far as the engine goes its bog standard...no porting, standard exhaust and inlet manifold, standard NA cam. I only got to 12 psi boost which gave
316lb/ft torque at 4,163 rpm
304.4 BHP at 5752 rpm flywheel 275.8BHP at wheels.

Not bad for an engine design that is probably 30yrs old, I wil scan the graphs in a min and post them.

The first graph was at 8psi of boost

LS1 V8 power is very similar : LS1 5.7 V8 305 bhp @ 5200 rpm, 320 lb-ft @ 4400 rpm
 

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jay28

Well-Known Forum User
wow they are great figures, gotta be happy with that. Is 12psi the max boost your going to run? or are you going to try for higher at some stage?
 

twoforty

Well-Known Forum User
No 12 psi is just as far as I got adjusting the fuel tables. I will probably run 20psi once its all done. The holset turbo doesn't even start to reach its compressor map until 15psi!!
 
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Zed2k

Well-Known Forum User
Great results, I'll be tseting mine soon, I am running 12.7 psi at present so be good to compare the two!!
 

spyro

Well-Known Forum User
Hi guys.

the engine... was it a rebuilt one, or just an old engine with a turbo jammed on it?

Im very interested in this as it will give me some idea where to start when I tune my supercharged motor.

What CR are you running? what head / block?

Im aiming for about 300RWHP personally. Enough to have fun with, without breaking the bank.
 

twoforty

Well-Known Forum User
It was a standard l28 but rebuilt....new psiton/rings/bearings etc.....I wanted an old one with some miles on to test with first but ended up building one up from scratch. An old 2.8 with a turbo strapped on it would be much the same though. CR worked out at 8.35:1 with 2mm head gasket
 

spyro

Well-Known Forum User
It was a standard l28 but rebuilt....new psiton/rings/bearings etc.....I wanted an old one with some miles on to test with first but ended up building one up from scratch. An old 2.8 with a turbo strapped on it would be much the same though. CR worked out at 8.35:1 with 2mm head gasket


Thanks for the info - which head / block though ?
 
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