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L28ET setup goin triple


chris51608

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Hi guys my name is chris and i have a L28ET motor .no turbo or intake/exhaust manifold..the motor has P90 head...F54 block with dish pistons.due to my budget during this thought times. I'm thinking of installing triple Weber on the motor..here the problem I'm new to the triples so i know I'm going to need flat top pistons and a different cam but what about the P90 head.what modification i will have to do to it?...I'm looking for some guidance on this one any help will be appreciated...My HP goal is 150-200hp .once again thanks

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due to my budget during this thought times. I'm thinking of installing triple Weber on the motor..

 

contradiction. :rolleyesg

 

 

 

 

 

If you want to run it N/A you can as is, but it will have a low CR and disappointing power.

You can swap another head on or shave the P90 down to bump up the CR.

 

Triples = $$$

 

 

If your on a budget just grab a set of used SU's, a spare E88 head and call it good for now.

(even Iv got a few just sitting in the shed)

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If your on a budget just grab a set of used SU's, a spare E88 head and call it good for now.
SKIB gave you good advice if money is tight. And shaving the head .080 isn't cheap when you add in the less-obvious costs for the spacers (~150 from Kameri) and longer valves (~150). A cam isn't too expensive if you go reground (again, ~150), but you'll also need new lash pads (~50). A well-setup L28 with a mid 8 CR and SUs can be a fun engine and can be done on the cheap quite easily.
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what if i buy flattop pistons for the F54 block ..and the P90 heads is good ..how much should i shave it of 0.80? i need help i have money its just hard to come by ...i need a good game plan to go by

 

If you are hard on cash why are you trying to modify a car? Have you thought about saving up for what you really want to do?

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If you are hard on cash why are you trying to modify a car? Have you thought about saving up for what you really want to do?

 

Beautiful!!!

 

This is exacly why people stay broke anymore. Not saying the OP is broke just saying if money is tight you should only be focused on your DD and keeping it reliable.

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150 is stock, and I mean bone-stock L28 low compression engine power.

My L28 from a 1980 280ZX 2+2 with 225,000 miles and 150psig compression across the board spun the dynojet to 146 hp.

 

I figure with a flat top engine and decent compression I'd have broken 150. Stock EFI system, stock intake, stock exhaust manifold... and a crush bent 2.5" exhaust.

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150 is stock, and I mean bone-stock L28 low compression engine power.

My L28 from a 1980 280ZX 2+2 with 225,000 miles and 150psig compression across the board spun the dynojet to 146 hp.

Tony, are you correcting for drivetrain loss, in other words, is that at the crank? I ask because we've done a few club dyno days and just about every stock L28 we've done was in the 120's at the wheels. Of course, we're at altitude (~5200 feet at the dyno) but I was under the impression that the dyno corrected its calculations for air temp and elevation.

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I spun 146 consistently on my junkyard L28 from a 1980 280ZX 2+2 (bought the whole car for $100...giving you an indication of the 'upkeep status' of the vehcile. It had 186K on it, and now the engine in it's transplanted body has 225K+ on it)

 

The dynojet HP number coincides with my GTech.

 

The number coincides (sorta) with my 1/4 mile time of 15.50 consistently (best of 15.50) with 2695# per SanAntonio Dragway scales wet with driver, and around 89mph in the traps.

 

As an aisde, the engine I REPLACED had a rod knock, but before going out I dynoed it as well. It had Triple Weber 40's, a Header, connected to the same crush-bent exhaust (2.5") and THAT combination spun aroudn 82HP to the rear wheels. I FELT fast as heck, but wasn't. Hence my use of the word 'Butt-Dyno Correction Factor' You would have SWORN the car with webers and header was WAY more powerful and faster, but infact was seriously down on power compared to the stock EFI system, running a K&N filter in the stock box, and the stock exhaust manifold. Quiet, and FAST!

 

I will not argue that the average tuned L28 will spin in the 120 - 130 range to the rear wheels. But there are tuning techniques on a bone-stocker that will net you measurable power at absolutely no cost for extras. For the record, I really didn't see any difference between the CAI or the stock K&N filter setup, or from running the paper filter. Other than the irritating HSSSSSSSSSSSSSSSSSSSSSSS at idle with the CAI wasn't there. I like quiet...

 

If you are at altitude, your power will suck dogs bollocks, it's not a number you can correlate. I think there is a sea-level correction factor, which should boot your 120's in to the mide 130's if not low 140's.

 

There is stock. Then there is stock. Look at an ITS 240 motor making 160HP from stock components. Same stuff you got on any other car, the difference is attention to detail.

 

I really would like to find an 'A' cam for my L28 and put that in there to see what kind of bump I would get. It falls off over 5800 like most L28's do, and with the "A" cam able to run up higher in the rpm range, I'm betting my engine would see a nice bump in performance at the rear wheels.

 

Anybody who has driven it says it's a hoot to drive. It's one of the reasons I tell guys to concentrate on driving and learning how to tune what they have. The STOCK stuff will give surprising results, and what you learn milking the power out of a stocker will translate to ANY OTHER VEHICLE. The stuff I'm doing was no different on a VW, or a Chevy. It's universal.

 

One thing I don't do, which confounds people, is dick around at the track with the car AT ALL. I drive it there, and run it. Guys fiddling all the time are usually hurting more than they're helping. About all I do it up tire pressure, and maybe swap to the open top air cleaner so you can hear the intake growl more on the track. Makes it more 'race car sounding'---like flipping the top on your dad's Impala for the drive to and from school, ya know?

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