A few top swap Questions

Ok, I want my car to be boosted and for the longest time now, I can't decide wheather to go turbo or top swap, so I have a few questions:

1. Would l32 heads. lim, and Gen V bolt up to a l36 block( and all the misc other crap, I'm sure a new alt bracket is needed to...)

2. What would be the cost(rough estimate, i know no one nows for sure)

3. I know it is like + 60 -70 hp for a top swap with a stock pulley, but would the added efficiency of the Gen V and l32 heads help out and make more?(on stock pulley)

4. I know MPG is gonna suck if I am always in boost, but do the tuned m90's get better mileage than the turbos, or vise-versa

Thanks in advance for any input

Hmm good questions I am going to keep an eye on this. Well I want to have a DD that is going to be reliable but you have to remember once you start modding that realiablity can go either way. But I had to look at what I was looking for overall out of the car. I want to take it to the track and autox and drag race. I want to get into the low 12's. From what I have read the L36 with a turbo its going to yield larger gains out of the box than a s/c would. Plus I just like the sound of a turbo rather than a s/c. Plus having a s/c and a turbo charge car would be nice too

yeah, i understand, thats why I didn't ask about relaibilty ... I know my trans will fail and I will cook many a tire, but this is my DD and If I want to run a car into the 11's it will be a second car... im looking for a low 13 to high 12, so the top swap, injectors, exhaust and hopefully an intercooler, this would cost less than the turbo(with a l67 top end) this is why Im curious about the L32 top now that there are more starting to show up in junk yards

L32 will work, but it will be a lot more expensive than using L67 stuff, just because it will be low milage. The L32 heads do have bigger vavles and with the added efficeny of the Gen V yes you will make more power pulley for pulley. You'll also "have" to run a 75mm TB because that's what coems stock on the L32's.

I've had a supercharged L36. For all the work it took me I really would have rather had gone to a non-intercooled Turbo kit with meth injection. And keep around 10psi. That would be enough for a low 13's pass if you can launch it well enough. By the time you buy heads/Gen V/TB/Intercooler/Head Studs/headers/gaskets the Top swap will probably be about the same cost as a turbo kit. With less room to advance. The Turbo's also going to be a much easier install !

I've seen turbo cars consistently get better gas milage up here, but that just might be a tuning difference between our two main tuners.

Just an FYI, my SSM90 (S/C kit from ZZP) WIth PEMs/SLP 1.8RR/3" DP/Catback and a 3.5 pulley I went 13.5@98.88 with a 1.9 60' . Stock GT Throttle body, a few degress of KR. So it works, but I really had no where to go without headers/cam etc... I sold the kit and was going to go turbo, but instead sold the car and built a motor for another GP and then it blew up I like the turbo option, with the twist of a wrist you can detrime how much power you want.

if youre only looking for low 13s or high 12s then just downgrade to an l67 system, itll be a lot cheaper and will get you there. honestly, you need the top swap, some headers/pems, rockers, and an intercooler to be there. dont waste money where its not needed.

Originally Posted by Bio248

if youre only looking for low 13s or high 12s then just downgrade to an l67 system, itll be a lot cheaper and will get you there. honestly, you need the top swap, some headers/pems, rockers, and an intercooler to be there. dont waste money where its not needed.

Downgrade? Although I would agree somewhat I wouldn't call switching from a newer na engine to a older sc engine neccesarily a downgrade. Especially when both of the engines are within a couple of years of each other. The advantage of doing a top swap is that it runs higher compression, it makes just a bit more power, it has a lil' weaker pistons and not reccomended for a reliable daily driver. Not saying your going to blow it up as soon as you step on it, because there are a lot of people running top swaps on dd's.

he said he wanted to use some l32 components for the top swap, thatd be the genV supercharged stuff. if he were to just use the l67 stuff itd save him quite a bit of money and his goal would still be very well within reach.

i had a top swapped l36 block and it seemed to run very well for the short time i had it. i am now with a full l67 swap to run more boost.

i suggest the L67 also... you can find the blowers for cheap. buy a machined intake for $100 , heads you can prolly find for $150-$200, youll need the fuel rail and injectors also.. if you get down in the low 13's on street tires.. then you just work on traction some DRs and a cable mod might make you touch a 12

It really almost sounds like if you have a L36 the turbo overall is the better way to go. Because of the advancement you would have vs. the top swap. Power and torque wise I would assume you would also be ahead of the game with a turbo?

i like the idea of a turbo and I know it is faster, I guess I am just having a hard time accepting the price, and if I do build my own turbo kit, It'll cost me 1500 dollars extra to buy a laptop and a turner....

But I guess I just need to stop being cheap and buy a GTP to build or some other car

just do a top swap, but use the l67 components. the car will be more than fast enough for you if youre only looking for low 13s. honestly, it doesnt take much for these cars to run consistant mid 13s and still be very reliable.

Originally Posted by 02BlueGT

i like the idea of a turbo and I know it is faster, I guess I am just having a hard time accepting the price, and if I do build my own turbo kit, It'll cost me 1500 dollars extra to buy a laptop and a turner....

But I guess I just need to stop being cheap and buy a GTP to build or some other car

Modding isn't cheap at all no matter which car you are modding. The top swap may just be the way for you. Can always make it faster too.

Oh I know modding isn't cheap, I meant get another car, so I don't have to risk being stranded with my DD with a blown trans or something.... But I guess we all risk it and that is the price of going fast in style

i spent alittle over $1500 for my top swap including install, had it done last winter. for the money i wish i would of went turbo but ahwell im happy with the added compression and better gearing i got with having a n/a car before hand. oh and i see about 30-35mpg on the eway and about 18-22 in the city. highway mileage went up but city went down as can be expected getting into boost

figure 3 grand for a turbo, or around a grand for a topswap


and to the guy who switched his top swap motor for and l67, that was a mistake. the m90 LOVES higher compression motors, cause the higher compression helps where the m90 falls off, uptop.

i have higher compression then 90% of people, figured 9.7:1, and i run a 2.6 at the track with no knock, and a 2.8 on the street with 18* of timing.

and, if you have a gt, you will have better gears, 3.29's

you will be very pleased.

i didnt say why i swapped it.

spun bearing. and i felt like having a safer to mod car anyway with the less finicky compression ratio.

yeah, this is why I figured the l32 top end, like 1500 for parts, and I could install it at home, just take a week off of work. a lot better than the 3k for a turbo

How does the GT trans hold up to the power, I know it depends on how you drive, but I usually drive pretty slow, and the track is an hour away, so an all out failure at the track would blow

only difference between a gt and gtp trans is the gearing, gt has 3.29's and gtp has 2.93's and the gtp gets an hd diff.

once my gtp trans **** out(its on its way) i am putting a gt trans in along with my hd diff.


dbtk on cgp has like 202k on his gt motor and trans, and puts out the same numbers as me, with no issues

my trans is holding up fine so far. it only starts to go bad if you do a lot of double downshifts or burnouts. if you treat it right it should last for a while with no problems.

take care of your car and it will take care of you.