WWR3VD: Bolt-ons v. Low Budget Turbo

[Andy348]

The car now:

'87 M20B25
Rebuilt 90,000km (55,000 mi) ago
Rebuilt starter/alternator
New distributor cap, plugs, wires
Stock exhaust w/cat removed (quieter than I would have liked)
New timing belt/water pump
Front suspension revamp done + brakes
Apex Springs/Bilstein Sport Shocks
2.73 open-diff
UUC SSK w/DSSR

So I've finally got my M20B25 swapped 325e running, and I'm a little disappointed. I came from the B27, which was slow as balls but felt a little quick (obviously because of the MASSIVE eta torque). Now I didn't expect the 170hp B25 to be fast, but I guess I was hoping it was quicker than what I'm feeling.

I've recently been told there is employment opportunities for me at my parents house in PEI, which includes a large garage and all the tools I will ever need, along with my dad for help (30 years+ car experience).

So now I've got two options. I can go the route of full bolt ons -> 3.73 LSD, Miller MAF + Chip, 19lb injectors, and KAI Motors Intake. I'll probably also run a 2.5" exhaust, sways, nicer stereo, do some weight reduction, and shave the engine bay. Total is ± $1500 (buying used parts).

The second option is a 7-8psi turbo set up running on motronic ecu. Parts would include 24lb injectors, revshift manifold adaptor, Holset HY35, eBay intercooler, ARP head studs, new head gasket, BOV, Begi FMU, stage 2 clutch (maybe not necessary), TCD motronic chip, M30 AFM, and a wideband 02 + other gauges. And before you tell me to buy a PNP megasquirt, try and find someone to tune/have a dyno in rural PEI farm country is not possible.

The greatest thing is that the car is not a DD, because I am not in need of a DD. I live in downtown Montreal, with an 8 minute commute to school. The car is stored at my friends house in the suburbs, where I only really drive it on weekends. However, it will need to make the 1200 km from PEI to Montreal at the end of the build.

While the price difference is quite significant (buying used parts, ±$1500/$2600), I'm more worried about going to bolt on route and feeling no power difference and want to turbo it anyways = $ down the drain. Also, next summer is a long way away, so I will have time to look for great deals to pop up on anything I choose.

Oh, and before you tell me to, all maintenance (hard fuel/brake lines, subframe bushings, rear brakes, tires, valve adjustment, etc) will be done before/at the same time of other modifications.

*flame suit on* Let's hear the suggestions!

[kamotors]

You will make a ton more power with a low budget turbo setup

[evandael]

you need a poll! i vote turbo.. but do it right. and swap the diff to a S3.73 before you do anything else.


i would budget around $3.5K (with a lot of supporting mods/maintenance like guibo, better mounts, o-ring the block, ARP headstuds, clutch, etc)

[Sagaris]

Even guys with the 1000hp Supras want more power.

Personally I would get a 3.73, 3.91, or 4.10 LSD
A MarkD chip
19# Design III injectors
Kamotors intake (for some nice noises)
your choice of exhaust ( also for some nice noises )
Do some weight reduction and spend the rest on upgrades that enhance the driving experience:

grippy tires, Z3 rack, H&R Race springs, and treat yourself to a couple local driving events.

Thats how I would do it at least.

[nando]

a "budget" turbo like you speak of will just end up costing triple what you originally spent, because you'll have to replace all the junkyard parts with better stuff, and doing something like Motronic with 24# injectors and an FMU = you'll blow up the engine sooner or later and have to replace it again.

I'd just leave it alone for now and do it right the first time. it'll be cheaper in the end.

[adonwilson]

Turbo. I have the 3.73, CAI, injectors, and straight pipes and my m20b25 is still WOW slow

Makes a lotta noise tho!

[euro2fast4u]

turbo budget build for me = $1800

http://www.youtube.com/watch?v=U7-ORHDbpq8

http://www.youtube.com/watch?v=CdgxMMIOgk4&feature=relmfu

2.93 open diff 195 tires


just saying with the proper knowledge you can do it

[Sagaris]

turbo budget build for me = $1800

http://www.youtube.com/watch?v=U7-ORHDbpq8

http://www.youtube.com/watch?v=CdgxMMIOgk4&feature=relmfu

2.93 open diff 195 tires


just saying with the proper knowledge you can do it

Very nicely done :up:

Im way too OCD to pull off a budget turbo build

[euro2fast4u]

Very nicely done :up:

Im way too OCD to pull off a budget turbo build

me too im redoing things to increase my reliability because you can only pick 2

fast cheap or reliable ..... choose

[OrganicMechanic]

if you just did the diff to a 3.73 or a 4.10 you will feel a huge difference.

[Andy348]

You will make a ton more power with a low budget turbo setup

No doubt about that. But is 80whp worth $1100 extra + incidentals?

you need a poll! i vote turbo.. but do it right. and swap the diff to a S3.73 before you do anything else.


i would budget around $3.5K (with a lot of supporting mods/maintenance like guibo, better mounts, o-ring the block, ARP headstuds, clutch, etc)

I'll put up a poll now.

My above budget (~$2600) includes a heavier duty eBay clutch, I've got brand new motor and tranny mounts, ARPs are included in the budget. O-ringing the block I may do I may not - I've heard it's not necessary when running 6-8psi, but shit happens.

Even guys with the 1000hp Supras want more power.

Personally I would get a 3.73, 3.91, or 4.10 LSD
A MarkD chip
19# Design III injectors
Kamotors intake (for some nice noises)
your choice of exhaust ( also for some nice noises )
Do some weight reduction and spend the rest on upgrades that enhance the driving experience:

grippy tires, Z3 rack, H&R Race springs, and treat yourself to a couple local driving events.

Thats how I would do it at least.

That's exactly the second option - it'll leave me a decent chunk for random expenses I don't account for, and my savings account will like it better.

a "budget" turbo like you speak of will just end up costing triple what you originally spent, because you'll have to replace all the junkyard parts with better stuff, and doing something like Motronic with 24# injectors and an FMU = you'll blow up the engine sooner or later and have to replace it again.

I'd just leave it alone for now and do it right the first time. it'll be cheaper in the end.

My plan was potentially (if funds allowed) to do the fmu + 24lbs, drive it for the summer and back home to Montreal, and then save up for a pnp MS and get it tuned correctly from a shop here.

I'll keep the in mind.

Turbo. I have the 3.73, CAI, injectors, and straight pipes and my m20b25 is still WOW slow

Makes a lotta noise tho!

This is what I'm afraid of lol, doing it all to find out that it doesn't feel 'fast'. It would help if I could drive a 3.73/CAI/Chip/MAF'd car -_-.

me too im redoing things to increase my reliability because you can only pick 2

fast cheap or reliable ..... choose

I'm going for cheap and reliable - thats why I'd go 6-7, maybe 8 psi max.

if you just did the diff to a 3.73 or a 4.10 you will feel a huge difference.

Yeah - the 2.73 is definitely a pig, but if I'm going turbo I don't think I'd be changing the diff because of the longer gears. And trying to find a LSD under $350 in Montreal is next to impossible.


Not sure where I'm leaning now... poll to be posted in a min


EDIT: I've also got an E block somewhere if someone recommends a 327i...

[nando]

if you already have an M20B25, leave it alone. there's basically nothing for you to gain with a 2.7 bottom end, especially if you're going to turbo it anyway.

[adonwilson]

This is what I'm afraid of lol, doing it all to find out that it doesn't feel 'fast'. It would help if I could drive a 3.73/CAI/Chip/MAF'd car -_-.

Mine doesnt have the MAF, but if you ever find youself in NJ lemme know haha You can take mine for a spin and piss my neighbors off too

[kamotors]

just realized you mention the car is NOT a daily driver, I don't see any reason why you shouldn't turbo if your looking for a fast car. A decent and reliable setup will cost about 2k when your all said and done and the 2 major expenses will be engine management and the turbo.

A GOOD low boost setup will not be much cheaper than a GOOD higher boost setup.

the only things I changed that didn't break and need replacing from my 7psi to 20psi setup is headstuds. even a low boost setup really benefits from a good engine management.

[F34R]

I went all out suspension first, what is the point of speed with a cheap suspension?

Suspension first then collect for a turbo over a small period of time.