l28et and e88 head

[sharjt]

I just got a cheap e88 head and was hoping someone could give me a little info on what it will do on a l28et.

[DustinZ]

Anything is possible with enough time and money..... Just kidding, I would be interested in what the outcome will be also.

[evildky]

it will raise you compression and give you smaller valves (both bad things) the E88 is pretty undesirable even for the N/A, when turbo, stick with the N42 if you want a higher compression ratio, or keep the compression stock with the P90 hydraulic if you don't want to have to adjust valve lash ever again, or the p90 mechanical if you want to increase the redline to 7k or higher, or a P79 if your in a pincha nd can't locate a P90

[sharjt]

I thought the E31 and the early '72 E88 head with 280 valves and cam would up my compression to 8.3 Which very close to the optimum 8.4 turbo compression. Not sure if I am going to do this just wanted some more opinions.

[evildky]

the E88 uses a slightly larger chamber than the E31, the E88 still uses the smaller valves, the head can be machined to accept the larger diameter valves from the later heads but you'll spend as much at the machine shop as buying a better head, also the E88 has more restrictive exhaust runners,and the e88 has what is generally considered to be a poor combustion chamber design inferior to the N and P series heads, the stock compression of the L28ET is about 7.3:1 the E88 would raise it to 8.3:1 with the standard OE headgasket (use the 1.0 or 2.0 head gsket to raise or lower the compressior ratio a bit) E31 is 42.4ccE88 has 44.7cc N42 has 44.6 but a better combustion chamber and the larger valvesP90 is 53.6cckeep the comperssion as close to stock as possible till you add an Intercooler, after that the 8.5:1 is a good ratio to run but can be deadly with increased boost without the intercooler

[DustinZ]

evildky, what overall setup would you recomend for sharjt? I thought he would be best with a t3/t4 50 trim but my turbo guy says he should run a 60-1. He plans on intercooling it and I have a 16bit z31 ecu and maf for him. I think he has a set of 550cc injectors to put in when all the upgrades are being done.

DustinZ

[evildky]

the To4E si what I am running, the 50 trim is fine if you want to run 16-20 psi, if you want to run 20-24 psi the 57 trim is a better choice, the 60-1 is quite large and would be too large to spool efficiently and really a good choice for a drag only car, i wouldn't suggest it for a street driven, road race or autocross car, as for the Z31 electronics' if your skilled enough to mapp the ecu for the larger injectors ro send it to jim wolf it's a good choice, i perfer the flexabulity of megasquirt or other stand alones, also with any of these turbo's the compressor housing will hit the exhaust manifold and must be run with a spacer and longer studs, the 60-1 would need about an inch of spacer and piping would be tight, the to4e's require only about 3/8