Opinion and sugestions on this 4AGE 20v 303HP Dyno run

[ArubaAe86]

Hi, guys. After a long wait and research I finally finished building my AE86 with a 4AGE 20v with forged internals. Below is a list of all the upgrades:

• ARIAS low comp. pistons 8.9:1 C.R.;
• 4AGZE supercharger connecting rods;
• ACL Race bearings with thrust washers;
• Cometic head gasket;
• ARP Main Studs;
• ARP Head studs;
• ARP Flywheel bolts;
• TOGA High Volume Oil Pump;
• 3SGTE 440cc injectors (injector upgrade);
• Custom made air intake manifold;
• 2.5” intercooler tubing with hoses and clamps;
• Denso Fuel Pump 950-0155 280Lph (liters per hour);
• HKS Universal SSQV3 BOV;
• Tial 38mm wastegate;
• 25x12x3 Intercooler;

The setup:


The 20v turbo reached about 303 HP with about 16-17 PSI of boost with a Garret T3/ T4 ball bearing Turbo and a MicroTech LT10 ECU. Here is the Dynojet graph.



A friend of mine told me that the current AIR/FUEL ratio is left dagerously LEAN.
I was wondering what you guys think about the graph? In advance many thanks for your help.

[Stolic]

New build, very tidy

would be good to see a boost graph if you got one?
I'd be tempted to throw some more fuel at it, any idea where the injector duty cycle was up to?

[ArubaAe86]

Thanks for the reply Stolic. Unfortunately I don't have a boost graph nor the injector duty cycle. The boost limit was left at about 17-20 PSI. They recommended me though to change the injector size for better performance.

New build, very tidy

would be good to see a boost graph if you got one?
I'd be tempted to throw some more fuel at it, any idea where the injector duty cycle was up to?

[Stolic]

yeah larger injectors would definitely help. Been building a similar setup for a friend of mine and I found that 440cc injectors would limit power beyond about 15psi.
We swapped to some Sard 750 injectors which should support boost beyond 25psi and get up around 400hp

[ap7]

That's a great result!

Would be keen to see how it goes with bigger injectors and little bit more boost?

[shrike]

10-10.5:1 is fine for on boost at wot as long as there is no pinging

the 14:1 will be at lower revs with less strain so dont freak out to much

What gear did you do the dyno pull at?

[Bazda]

300hp atw is pretty standard for a 4age 20v silvertop at that boost level.

A/F looks ok in some areas but very lean in others. I would get it retuned.

[RT40Corona4AGTE]

I agree with Bazda, a re-tune is required as that appears a bit on the lean side of things for my liking.

Maybe they were limited by your injector size? Have a chat with them and ask a few questions as to why the AFR's are lean and see what they say.

Congrats with the build!

[BLSTIC]

That's pretty damn impressive. I know a few supercharged 5L engines that are only just above that mark...

As for your air-fuel ratios remember that the excess fuel (after 12 or 13:1) is there to stop pinging. If your intake temperature is cold, your fuel is always top notch and the timing isn't too aggressive it will probably survive. But you can only control one of those variables with any certainty... So do what ^^^ those guys said and get some more fuel into it. Or run a GOOD water injection system, but those are expensive or difficult to setup with fail-safes (i.e. drops boost when it detects a problem) and not many tuners have faith in it.

Also the LT10, is it set up to run sequential injection? That makes large injectors much more easy to deal with at light loads.

Out of curiosity, what head and inlet manifold are you running on that? I always figured the silver-top would be a PITA to tune by MAP sensor, so I assume you have a black-top setup there?