basic advice for a turbo'd higher reving 4.8
 

Hey guys I picked up an 87 e30 Im planning on doing a budget 4.8 turbo swap in and for starters hoping to make 400-500 whp and very drift friendly. anyways...

First and foremost(I know not the best place for a trans question)

1. Manual Transmission/what are good budget options that will bolt up to a 4.8 (2004)

• t56 (obviously) but quite spendy
• I read old muncies?
• super T10's might work?
• I also see the 4.8's came with a manual does anyone know what these can handle??

Engine
I have access to local 2003 and 2004 4.8's with 140XXX or so for 300$ Im ready to pull the trigger on. Im looking to keep this as stock as possible/save my money and throw a turbo in (ebay Gt45 seems to be quite common on here?)

REV Ive read in here ppl get these revving to 7700rpm with very minor work but I cant find exactly whats needed to do so. I'm assuming valve springs at the least?


I'll keep researching my other questions in the mean time but for now if anyone could weigh in Id be very appreciative
Thank you!
Phil

The thing with turbos and high revving is it's not needed and is entirely subject to turbo size. You can get away with a lot of hp and only 6500 rpm but if you want to zing it I would put some 243's, springs, cam and a Victor jr then take it to 8500.

Hey thanks for the reply,
that makes sense prolly only need it to rev high with a larger turbo, Id love for this to rev out especially being a manual.. but I dont want to get over my head with everything

I can get a victor jr for 150(granted it clears the hood). can I ask the point of this intake?
243's maybe for 250ish used
ls9 cam 115$ I do nottt want an aggressive cam, (hoping to idle like a sleeper)
ls1/6 beehive springs? go 65 on ebay...$

So 600$ in parts will rev this to 8500? In all reality i might just throw this engine in with a turbo for starters and go from there BUT can anyone weigh in on how worth while it would be to make this rev that high

i spin my 4.8 / 7875 combo to 7200 100% stock internals


there is no cheap manual transmission that can hold a turbo'd V8

I've had mine up to 7800 on accident a few times. Stock bottom with cam/spings/pushrods. Not really any reason to take it that high unless its still making power. With your power goal, you won't need anywhere near that rpm.

You'll probably run into valve float with stock lifters if you plan to run it much past 7k. To build an engine that revs to 8500 more reliably, you'll probably need solid lifters. As others have said though, for your goals you shouldn't need to rev that high. You'll be blowing tires off as soon as it's in boost which depending on your setup is probably closer to 3k. Feathering it to stay around 6k would be a good range for drifting and will be much more friendly on your valvetrain.

As far as turbo selection, the cheap GT45 turbos aren't very compatible with nearly any other supporting parts. There are better cheap turbos to go with that will be more interchangeable. On3performance has some really inexpensive turbos.

For further info and references, I'll direct you to Moat Hoeppel's pages:
https://sites.google.com/site/sloppywiki/
https://sloppymechanics.com/
https://www.youtube.com/user/denmah

another issue you may find the hard way, is the oil pump isn't really adequate for sustained high rpm flow, without getting air (cavitation), I'd say above 7500 for long durations like Drifting where the load and rpm are high on parts and oil pickup... many who know they plan to rev usually plan out a dry sump, yet you could get lucky and swap out the stock pump for a upgraded Katech unit, or roll the dice and enjoy, since its a $300 engine.... as others mention, Cam, Valve Train, properly sized turbo for what your planning, you could get the 400-500 rwhp with a 5.3 and good heads with proper RPM and matched components

So 600$ in parts will rev this to 8500? love it!!!!!

If you want longevity keep the revs below 7200rpm. The higher you rev it..... truly the less life you will get. Even with titanium valves. Going above that number for the most part should require lighter valves and better lifters. Most go solid roller for reliability.

I rev'd a turbo setup (4.065" bore/3.622" stroke) to 7500rpm + hundreds of times making over 1000rwhp..... but after tear down my machinist said I beat up the valves and it needed a fresh valve job which was only about 3-4K miles. Albeit very hard miles. 2.16" s/s valves and believe it or not LS7 lifters.

Downshift- spend the entire weekend or longer on here doing research. You can actually educate yourself and answer 95% of your own questions.

Bottom line... there is no cheap way to make an engine reliable above 7500rpm.... 8000rpm costs $$$ 8500rpm+ costs $$$$ and so on!

Hey everyone thanks for all the advice!
I'll definitely look into those other turbos and keep all this in mind! im definitely going to keep researching before i do anything

"truck doug" Thats pretty cool, 7200 would be a cool # for me to start but im at work and i'll read through all this a bit more thoroughly later
thanks again

Any suggestions on a good platform for a transmission to build that might not blow my budget...?

Look into Nissan 300zx (Z32) 5 speed transmission swaps. You can buy a swap kit for about $600 and they claim these transmission will hold around 700hp in stock form and cheap ($300ish) from the junkyard.

isnt that basically a t5?


edit, nope i'm wrong. it was the z31 trans that was a BW T5 with nissan bell and output
aka the FS5R90A

KB is talking about the RS5R30A

What cam?

very similar to the sloppy stage 2 cam, psi 1511ml springs. Sorry I meant stock bottom end.

You'll need to either decap injectors or buy some 80's and make sure you have enough pump to support the fuel needs.

If you decap you might want to send them out for cleaning and flow work.

Alot of wear and tear lies in the cam lobe profile/lift and the weight of the valve itself. The larger the valve the less you can get away with... same goes for the ramp rate on the cam lobe.

Grab a super mild symmetrical lobe cam with a .600" or less lift. Stick with the small valve (aka lighter weight valve) OEM heads no one wants. Run a quality light weight single beehive like the PSI 1511 with titanium retainers and a decent push rod.

Friends 4.8 has been running for years buzzing 7500 on a regular basis with no signs of valve damage. Factory lifters and all... Recently had the heads off for inspection and they looked great. This is with the factory original valve job and 150k on the heads when he installed the cam.