TOMEI PONCAMS ON S15 TURBO and E85.

[Dboyizmlg]

It's been a few weeks since I got my tune.
I want to add Tomei 256 poncams I'm thinking I will have an extra 15-20whp by adding this to my set up.

Any ways my question is will I have to get a re-tune for this, or just slap them on and call it a day.

Here is the mood list:
S13 Sr20det
-stock every thing (block, and head)
-S15 turbo (plain bearing 75foo model)
-tomei 740cc inj
-PFC
-3inch back exhaust from elbow to muffler.
-E85

It made 284 whp, and 310lbs tq at 18psi (dropped back down to 14psi around 6k. It was tuned by Kogi on a Dyna pack.

Will I need a re tune, or is it safe without it?

[teh smithers]

Straight from Tomei's catalog:

"PONCAM: High performance can be gained by easy installation. Drop in camshafts that are designed to suit the stock valve train and ECU."

Based on that, I'd say you probably won't grenade your motor if you just slap them on. But if I were you, I'd get it tuned again. It's safer, and you'll probably get better gains out of the cams.

[genericforumname]

My Zenki S14sr is mostly the same as your S15 model except I'm using 550's without E85 and a 3 inch turbo back and I'm using Tomei 256's as well and honestly I would re-tune it. Mine's running a ROM so it's easy to re-flash but I agree with Teh Smithers it will probably be fine for a short time under low loads but I wouldn't floor it and I wouldn't leave it like that forever either.

[Dboyizmlg]

Straight from Tomei's catalog:

"PONCAM: High performance can be gained by easy installation. Drop in camshafts that are designed to suit the stock valve train and ECU."

Based on that, I'd say you probably won't grenade your motor if you just slap them on. But if I were you, I'd get it tuned again. It's safer, and you'll probably get better gains out of the cams.

That's what I was thinking!
Just glad I had the same opinion.

[Dboyizmlg]

My Zenki S14sr is mostly the same as your S15 model except I'm using 550's without E85 and a 3 inch turbo back and I'm using Tomei 256's as well and honestly I would re-tune it. Mine's running a ROM so it's easy to re-flash but I agree with Teh Smithers it will probably be fine for a short time under low loads but I wouldn't floor it and I wouldn't leave it like that forever either.

Since I'm on E85 I would think I have a lot more room to go lean with the Cam upgrade so I was a bit worried about that.
But you are right, as long as I'm not at WOT most the time I would be ok.

Re-tune would be wise decision

[pacotaco345]

Do you have a wideband? I know with my poncams (rebuilt stock sr with s15bb t28) the mileage dropped a decent amount post cams and retune. This was just cruising along too not in boost.

[RalliartRsX]

Since I'm on E85 I would think I have a lot more room to go lean with the Cam upgrade so I was a bit worried about that.
But you are right, as long as I'm not at WOT most the time I would be ok.

Re-tune would be wise decision


That is the incorrect thought process. E85 is able to burn much cooler and has the octane (knock prevention) rating close to race gas. This means you can get away with MUCH more timing (where ICE make thier power) NOT leaner conditions!

Be careful!

Typically, drop in cams (like the pon cams) only need a slight adjustment in tune as they do not necessarily change the A/F ratio (or I should say, not by too much, unless the tune is on the raged edge) in a huge way as compared to the ability for the engine to ingest and expel it's charge more efficiently (more charge may mean a leaner A/f mixture).

[Def]

E85 will make more power at richer mixtures, but it will also tolerate running a bit leaner than 93 when pushed to the limit. The knock limit is so far out there it gives lots of headroom for a variety of operating conditions vs. 93 octane (or the dreaded 91 octane CA pee-gas).

[Dboyizmlg]

That is the incorrect thought process. E85 is able to burn much cooler and has the octane (knock prevention) rating close to race gas. This means you can get away with MUCH more timing (where ICE make thier power) NOT leaner conditions!

Be careful!

Typically, drop in cams (like the pon cams) only need a slight adjustment in tune as they do not necessarily change the A/F ratio (or I should say, not by too much, unless the tune is on the raged edge) in a huge way as compared to the ability for the engine to ingest and expel it's charge more efficiently (more charge may mean a leaner A/f mixture).


I am aware of how E85 works.

With the Cam upgrade I would think it would lean it out a bit is what I was trying to say.

[Dboyizmlg]

The tune is also a very conservative one.
Safe to say its good for a DD beating, and track car beating.